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Y E. " Sustainable Materials and Construction Technology.". In: AAK Mombasa Chapter: Seminar. Royal Court Hotel, Mombasa; 2006.
Y E. "Environmental considerations shaping the hospital building and governing its space.". In: AMEK 3rd Scientific Conference & Exhibition,. NHIF Building, Nairobi.; 2005.
Y G, M K, NM I, ILAKO DR. "The Influence of Central Corneal Thickness on Intraocular Pressure Measured by Goldmann Applanation Tonometry Among Selected Ethiopian Communities." J Glaucoma. 2010 Feb 15. 2010. Abstract

BACKGROUND: Estimates of intraocular pressure (IOP) are influenced directly by the central corneal thickness (CCT). We assume and apply a single value for CCT (520 mum) in applanation tonometry estimates, although there is compelling evidence that CCT varies between individuals.
OBJECTIVE: To determine the influence of CCT and other factors on IOP among Ethiopians.
METHODS: A cross sectional study was conducted among 300 sampled individuals from June to July 2006. The CCT was measured using OcuScan(R) RxP Ophthalmic Ultrasound and readings of IOP were made with Goldmann applanation tonometer. The data was analyzed using SPSS version 12 and S-Plus 2000 of statistical packages.
RESULTS: Out of 300 individuals, 184 (61.3%) were males. The mean age was 42.57 years (SD+/-16.71), mean IOP 13.39 mm Hg (SD+/-2.81), and mean CCT 518.68 mum (SD+/-32.92). There was statistically significant relationship between CCT and IOP (r=0.199, P<0.001) and a borderline statistically significant detectable change of CCT with age (r=0.012

J
JOHN DRYABS, YABS DRJOHN. "Kenya's Role in the Implementation of Industrial Development Decate for Africa (I.D.D.A.). A Paper presented at a Regional Workshop on I.D.D.A in Addis Ababa,.". In: An Article in the Underwriter Journal. SITE; Submitted. Abstract

This paper describes the methodology and presents preliminary results of an economic appraisal of a community based health care project in Kenya. Community health workers, trained for 12 weeks and deployed in two locations in Kenya's Western Province, act as first contact providers of basic health care and promoters of selected health, sanitation and nutrition practices. A Cost Benefit Analysis has been undertaken using the Willingness to Pay approach to compare the costs of the project and its benefits. The benefits are in the form of more easily accessible basic health care and are measured as consumer surplus accruing to the community. Gain in consumer surplus is consequent on the fall of average user costs and rise in utilisation of the project established points of first contact with primary health care. The argument for the economic viability of the project is validated by the large Net Present Value and Benefit Cost Ratio obtained for the whole of the project area and for the two locations separately. Although the evaluation technique used faces the problem of valuation of community time, aggregation of health care services at all points of first contact and the partial nature of cost benefit analysis evaluations, the results are strongly in favour of decentralisation of primary health care on similar lines in the rest of the country.

Y
YABS DRJOHN. "Small Business Powers Development. The role of Small Scale Business in Economic Developent in Kenya.". In: Ufanisi Journal No.47. Lelax Global (K) Ltd; Submitted. Abstract

The book is a biography of the author. He begins with fundamenbtal question whether we can determine our destiny or we are just fulfiling what has already been ordained. He then explains how he has grown over the yeas experiencing changes.  

Yadav G, Saskin R, Ngugi E, Kimani J, Keli F, Fonck K, MacDonald KS, Bwayo JJ, Temmerman M, Moses S, others. "Associations of sexual risk taking among Kenyan female sex workers after enrollment in an HIV-1 prevention trial." JAIDS Journal of Acquired Immune Deficiency Syndromes. 2005;38:329-334. Abstract
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and Yalla GPPO. "Effect of National Strategy Implemetation on Competitiveness: A case of Kenya's Trade, International Marketing and Investment Strategies." International Journal of Business and Public Management. 2011;Vol 1, No. 1: (April, 2011):60-68.
Yamamoto LG, Morita SY, Boychuk RB, Inaba AS, Rosen LM, Yee LL, Young LL. "Stool appearance in intussusception: assessing the value of the term “currant jelly”." The American journal of emergency medicine. 1997;15:293-298. AbstractWebsite
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Yamoah CF;, Mulongoy K;, Agboola AA;, Ssali H;, Keya SO. "Decomposition and nitrogen contribution by prunings of selected legumes in alley cropping."; 1985.
Yanda PZ, Wandiga SO, Kangalawe RYM, Opondo M, Olago D. "Adaptation to Climate Change - Induced Malaria and Cholera in the Lake Victoria Region.". 2018. Abstractrepository.costech.or.tz

AIACC Working Papers, published on-line by Assessments of Impacts and Adaptations to Climate Change (AIACC), is a series of papers and paper abstracts written by researchers participating in the AIACC project. Papers published in AIACC Working Papers have been peer reviewed and accepted for publication in the on-line series as being (i) fundamentally sound in their methods and implementation, (ii) informative about the methods and/or findings of new research, and (iii) clearly written for a broad, multi-disciplinary audience. The purpose of the series is to circulate results and descriptions of methodologies from the AIACC project and elicit feedback to the authors. The AIACC project is funded by the Global Environment Facility, the Canadian International Development Agency, the U.S. Agency for International Development, and the U.S. Environmental Protection Agency. The project is co-executed on behalf of the United Nations Environment Programme by the global change SysTem for Analysis Research and Training (START) and The Academy of Sciences for the Developing World (TWAS).

Yanda P, Wandiga S, Kangalawe R, Opondo M, Olago D, Githeko A, Downs T, Robert Kabumbuli, Opere A, Githui F, Kathuri J, Olaka L, Apindi E, Marshall M, Ogallo L, Mugambi P, Kirumira E, Nanyunja R, Baguma T, Sigalla R, Achola P. "Climate, Malaria and Cholera in the Lake Victoria Region: Adapting to Changing Risks.". In: Climate Change and Adaptation. Routledge; 2012. Abstract

In the East African countries, malaria is ranked as the primary cause of morbidity and mortality in both children and adults. It causes about 40,000 infant deaths in Kenya each year; in Uganda annual cases of malaria range between 6 to 7 million, with 6500 to 8500 fatalities, and in Tanzania the annual death toll is between 70,000 and 125,000 and accounts for 19 per cent of health expenditure (De Savigny et al, 2004a and b). In the case of cholera, the first epidemic in Africa was reported as far back as 1836 (Rees, 2000). Major outbreaks were next reported in 1970 and affected West Africa (Guinea), the horn of Africa (Ethiopia, Somalia and Sudan) and Kenya (Waiyaki, 1996). The most severe cholera outbreak on the African continent was in 1998, accounting for more than 72 per cent of the global total number of cholera cases and acutely affecting the Democratic Republic of Congo, Kenya, Mozambique, Uganda and the United Republic of Tanzania. Cholera outbreaks in East Africa have been reported to the World Health Organization (WHO) since 1972. In the Lake Victoria region of East Africa both malaria and cholera are common, with malaria endemic in the lowlands and epidemic in the highland areas and cholera endemic in the basin since the early 1970s (Rees, 2000).

Yanda PZ, Wandiga SO, Kangalawe RYM, Opondo M. "Adaptation to climate change/variabilityinduced highland malaria and cholera in the Lake Victoria Region." COSTECH Integrated Repository. 2016. AbstractWebsite

Global climate change and its interactive components, such as water availability, related vulnerability of natural and socio-economic systems and health, changes in land use, as well as availability, quality, quantity of water and related policies, affects human wellbeing. The apparent correlation between disease outbreaks, such as malaria, cholera, rift valley fever, and meningitis—all of which are sensitive to climate variability (McCarthy et al., 2001)—and the strong El Niño years, e.g., 1982–1983 and the 1997–1998 events indicates a causal link between climate and health. Integrated climate-disease models show that rates of infections can be affected by climatic anomalies.

Yangyuoru PM, Otieno AC, Mwongela SM. "Determination of Sphingosine Kinase 2 Activity using Fluorescent Sphingosine by Capillary Electrophoresis." Electrophoresis. 2011;32(13):1742-9.
Yangyuoru PM, Latanya Hammonds-Odie, Mwongela SM. "Fluorescent lipids as probes for sphingosine kinase activity by capillary electrophoresis." Capillary Electrophoresis of Biomolecules. 2013:329-340.
Yangyuoru PM, Antonio MD, Ghimire C, Biffi G, Balasubramanian S, Mao H. "Dual Binding of an Antibody and a Small Molecule Increases the Stability of TERRA G‐Quadruplex." Angewandte Chemie International Edition. 2015;54(3):910-913.
Yangyuoru PM, Dhakal S, Yu Z, Koirala D, Mwongela SM, Mao H. "Single-molecule measurements of the binding between small molecules and DNA aptamers." Analytical chemistry. 2012;84(12):5298-5303.
Yangyuoru PM, Zhang AYQ, Shi Z, Koirala D, Balasubramanian S, Mao H. "Mechanochemical Properties of Individual Human Telomeric RNA (TERRA) G‐Quadruplexes." ChemBioChem. 2013;14(15):1931-1935.
Yangyuoru PM, Bradburn DA, Liu Z, Xiao TS, Russell R. "The G-quadruplex (G4) resolvase DHX36 efficiently and specifically disrupts DNA G4s via a translocation-based helicase mechanism." Journal of Biological Chemistry. 2017:jbc. M117. 815076.
Yaouba S, Koch A, Guantai EM, Derese S, Irungu B, Heydenreich M, Yenesew A. "Alkenyl cyclohexanone derivatives from Lannea rivae and Lannea schweinfurthii." Phytochemistry letters. 2018;23:141-148. AbstractJornal article

Abstract
Phytochemical investigation of the CH2Cl2/MeOH (1:1) extract of the roots of Lannea rivae (Chiov) Sacleux (Anacardiaceae) led to the isolation of a new alkenyl cyclohexenone derivative: (4R,6S)-4,6-dihydroxy-6-((Z)-nonadec-14′-en-1-yl)cyclohex-2-en-1-one (1), and a new alkenyl cyclohexanol derivative: (2S*,4R*,5S*)-2,4,5-trihydroxy-2-((Z)-nonadec-14′-en-1-yl)cyclohexanone (2) along with four known compounds, namely epicatechin gallate, taraxerol, taraxerone and β-sitosterol; while the stem bark afforded two known compounds, daucosterol and lupeol. Similar investigation of the roots of Lannea schweinfurthii (Engl.) Engl. led to the isolation of four known compounds: 3-((E)-nonadec-16′-enyl)phenol, 1-((E)-heptadec-14′-enyl)cyclohex-4-ene-1,3-diol, catechin, and 1-((E)-pentadec-12′-enyl)cyclohex-4-ene-1,3-diol. The structures of the isolated compounds were determined by NMR spectroscopy and mass spectrometry. The absolute configuration of compound 1 was established by quantum chemical ECD calculations. In an antibacterial activity assay using the microbroth kinetic method, compound 1 showed moderate activity against Escherichia coli while compound 2 exhibited moderate activity against Staphylococcus aureus. Compound 1 also showed moderate activity against E. coli using the disc diffusion method. The roots extract of L. rivae was notably cytotoxic against both the DU-145 prostate cancer cell line and the Vero mammalian cell line (CC50 = 5.24 and 5.20 μg/mL, respectively). Compound 1 was also strongly cytotoxic against the DU-145 cell line (CC50 = 0.55 μg/mL) but showed no observable cytotoxicity (CC50 > 100 μg/mL) against the Vero cell line. The roots extract of L. rivae and L. schweinfurthii, epicatechin gallate as well as compound 1 exhibited inhibition of carageenan-induced inflammation.

Graphical abstract

Yaouba S, Valkonen A, Coghi P, Gao J, Guantai EM, Derese S, Wong VKW, Erdélyi Máté, Yenesew A. "Crystal Structures and Cytotoxicity of ent-Kaurane-Type Diterpenoids from Two Aspilia Species." Molecules. 2018;23(12):31-99. Abstract

A phytochemical investigation of the roots of Aspilia pluriseta led to the isolation of ent-kaurane-type diterpenoids and additional phytochemicals (1–23). The structures of the isolated compounds were elucidated based on Nuclear Magnetic Resonance (NMR) spectroscopic and mass spectrometric analyses. The absolute configurations of seven of the ent-kaurane-type diterpenoids (3–6, 6b, 7 and 8) were determined by single crystal X-ray diffraction studies. Eleven of the compounds were also isolated from the roots and the aerial parts of Aspilia mossambicensis. The literature NMR assignments for compounds 1 and 5 were revised. In a cytotoxicity assay, 12α-methoxy-ent-kaur-9 (11), 16-dien-19-oic acid (1)(IC 50= 27.3±1.9 µM) and 9β-hydroxy-15α-angeloyloxy-ent-kaur-16-en-19-oic acid (3)(IC 50= 24.7±2.8 µM) were the most cytotoxic against the hepatocellular carcinoma (Hep-G2) cell line, while 15α-angeloyloxy-16β, 17-epoxy-ent-kauran-19-oic acid (5)(IC 50= 30.7±1.7 µM) was the most cytotoxic against adenocarcinomic human alveolar basal epithelial (A549) cells.

Yarmoshuk AN, Gauntai A, Mwangu M, Cole D, Zarowsky C. "Resilient and responsive Global Health partnerships of East African universities in a changing world.". In: Fourth Global Symposium on Health Systems Research.; 2016.resilient_and_responsive_global_health_partnerships_of_east_african.pdf
Yarmoshuk AN, Guantai AN, Mwangu M, Cole DC, Zarowsky C. "Mapping International University Partnerships Identi fi ed by East African Universities as Strengthening Their Medicine, Nursing, and Public Health Programs." Annals of Global Health. 2016;82(5):665-677. Abstract2016_-_mapping_international_university_partnerships.pdf

Background: International university partnerships are recommended for increasing the capacity of sub-Saharan African universities. Many publications describe individual partnerships and projects, and tools are available for guiding collaborations, but systematic mappings of the basic, common characteristics of partnerships are scarce.

Objective: To document and categorize the international interuniversity partnerships deemed significant to building the capacity of medicine, nursing, and public health programs of 4 East African universities.

Methods: Two universities in Kenya and 2 in Tanzania were purposefully selected. Key informant interviews, conducted with 42 senior representatives of the 4 universities, identified partnerships they considered significant for increasing the capacity of their institutions' medicine, nursing, and public health programs in education, research, or service. Interviews were transcribed and analyzed. Partners were classified by country of origin and corresponding international groupings, duration, programs, and academic health science components.

Findings: One hundred twenty-nine university-to-university partnerships from 23 countries were identified. Each university reported between 25 and 36 international university partners. Seventy-four percent of partnerships were with universities in high-income countries, 15% in low- and middle-income countries, and 11% with consortia. Seventy percent included medicine, 37% nursing, and 45% public health; 15% included all 3 programs. Ninety-two percent included an education component, 47% research, and 24% service; 12% included all 3 components.

Conclusions: This study confirms the rapid growth of inter-university cross-border health partnerships this century. It also finds, however, that there is a pool of established international partnerships from numerous countries at each university. Most partnerships that seek to strengthen universities in East Africa should likely ensure they have a significant education component. Universities should make more systematic information about past and existing partnerships available publicly.

Yaşargil MG. Clinical {Considerations}, {Surgery} of the {Intracranial} {Aneurysms} and {Results}. Newyork: Thieme; 1984. Abstract

Clinical Considerations, Surgery of the Intracranial Aneurysma and Results

Yaşargil MG. Clinical {Considerations}, {Surgery} of the {Intracranial} {Aneurysms} and {Results}. Thieme; 1984. Abstract

Clinical Considerations, Surgery of the Intracranial Aneurysma and Results

Yazan A.M. Elhadi, D.M. Nyariki WVO, Ekaya WN. "Factors Influencing Transient Poverty among Agro-pastoralists Semi-Arid areas of Kenya." African Crop Science Journal. 2012;20:113-122. Abstract
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Yazan A.M. Elhadi, D.M. Nyariki WVO, Ekaya WN. "Transient Poverty among Pastoral Households in the Semi-Arid Lowlands of Baringo District, Kenya." . Ozean Journal of Social Sciences. 2012;5:9-19. Abstract
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Yazan Elhadi A, Nyariki DM, Wasonga VO. "Food Poverty among Pastoral Communities in Dryland Kenya.". In: RUFORUM Third Biennial Conference, Entebbe, Uganda, 24-28 September 2012. RUFORUM; 2012. Abstract
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Yenesew A, Muiva-Mutisya L, Macharia B, Heydenreich M, Andreas Koch, Hoseah M. Akala SDLOK. "6α-Hydroxy-α-toxicarol and (+)-Tephrodin with antiplasmodial activities from Tephrosia species." Phytochemistry Letters . 2014. Abstractpaper_75_muiva_et_al_phyto_2014.pdf

The CH2Cl2/MeOH (1:1) extract of the roots of Tephrosia villosa showed good antiplasmodial activity against the chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum with IC50 values of 3.1 ± 0.4 and 1.3 ± 0.3 μg/mL, respectively. Chromatographic separation of the extract yielded a new rotenoid, 6α-hydroxy-α-toxicarol, along with five known rotenoids, (rotenone, deguelin, sumatrol, 12a-hydroxy-α-toxicarol and villosinol). Similar treatment of the extract of the stem of Tephrosia purpurea (IC50 = 4.1 ± 0.4 and 1.9 ± 0.2 μg/mL against D6 and W2 strains of P. falciparum, respectively) yielded a new flavone having a unique substituent at C-7/C-8 [trivial name (+)-tephrodin], along with the known flavonoids tachrosin, obovatin methyl ether and derrone. The relative configuration and the most stable conformation in (+)-tephrodin was determined by NMR and theoretical energy calculations. The rotenoids and flavones tested showed good to moderate antiplasmodial activities (IC50 = 9 − 23 μМ). Whereas the cytotoxicity of rotenoids is known, the flavones (+)-tephrodin and tachrosin did not show significant cytotoxicity (IC50 > 100 μМ) against mammalian African monkey kidney (vero) and human larynx carcinoma (HEp2) cell lines.

Yenesew A, KARIUKI HELLENN, Patel NB, Mbugua PM, Kanui TI. "Antinocieptive activity of Toddalia asiatica (L) Lam. in models of central and peripheral pain.". 2012.
Yenesew A. "The first 9-hydroxyhomoisoflavanone, and antiplasmodial chalcones, from the aerial exudates of Polygonum senegalense." Arkivoc 21-27. . 2007;ix:21-27. Abstractpaper_43_midiwo_et_al_arkivok_2007_21-27.pdf

Phytochemical re-examination of the aerial exudates of Polygonum senegalense forma senegalense has resulted in the isolation and charachterization of a novel homoisoflavonoid, 5,7-dihydroxy-3-(hydroxy-phenyl-methyl)-6-methoxy-chroman-4-one (trivial name: polygohomoisoflavanone). The structure was determined on the basis of spectroscopic evidence. The new compound along with other components of the aerial exudate showed good antiplasmodial activities towards chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum.

Yenesew A. "Bioactive compounds from some Kenyan ethnomedicinal plants: Myrsinaceae, Polygonaceae and Psiadia punctulata." Phytochemical Reviews . 2002;1:311-323. Abstractpaper_29_midiwo_et_al_phytochemical_rev_2002.pdf

here are several described medicinal plants in Kenya from a flora of approximately 10,000 members. Strong cross-medical information from the 42 ethnic groups points to the high potential of some of these species. The Myrsinaceae are well established ethno-anthelmintics and anti-bacterials. They are harbingers of long alkyl side chain benzoquinones which clearly have a protective function from their histochemical disposition. The main benzoquinone in the sub-family Myrsinodae is embelin while for the Maesodae it is maesaquinone together with its 5-acetyl derivative; the distribution of these benzoquinones by their alkyl side chain length or the presence/absence of a 6-methyl group is in accord with morphological sub-family de-limitation. The benzoquinones showed anti-feedant, anti-microbial, phytotoxic, acaricidal, insecticidal and nematicidal activity. Many other benzoquinones of medium and minor concentration were also isolated and characterised. Some plants belonging to the Polygonaceae which are widely used as ethno-anthelmintics have been studied. The common anthelmintic anthraquinones were obtained from all five Rumex species while the naphthalenic acetogenin derivative, nepodin was more selectively distributed. The leaf of Polygonum senegalense is up to 17% surface exudate; about thirteen non polar flavonoid derivatives (chalcones, dihydrochalcones, flavanones and a flavone) have been isolated from it. From the internal aerial tissues of this plant, the major flavonoids were common flavonoids, quercetin, kaempferol, luteolin and their glycosides. The only unique compound isolated from this plant was 2′-glucosyl-6′-hydroxy-4′-methoxydihydrochalcone whose aglycone, uvangolatin is part of the exudate mixture. Other leaf exudate plants studied include the stomach-ache medicine, Psiadia punctulata (Compositae) from which novel methylated flavonoids, kaurene and trachyloban diterpenes have been found.

Yenesew A, Kiplagat J, Derese S, Midiwo JO, Kabaru JM, Heydenreich M, Peter MG. "Two unusual rotenoid derivatives 7a-o-methyl-12a-hydroxydeguelol and spiro-13-homo-13-oxaelliptone, from the seeds of Derris trifoliata." Phytochemistry. 2006;67:988-991.
Yenesew A. "8-Methoxyneorautenol and Radical Scavenging flavonoids from Erythrina abyssinica." Bull. Chem. Soc. Ethiopia . 2009;23:205-210. Abstractpaper_47_yenesew_et_l_bull_chem_soc_ethiop-2009-23-205.pdf

A new pterocarpan (named 8-methoxyneorautenol) was isolated from the acetone extract of the
root bark of Erythrina abyssinica. In addition, the known isoflavonoid derivatives eryvarin L, erycristagallin and
shinpterocarpin were identified for the first time from the roots of this plant. The structures were determined on the basis of spectroscopic evidence. The new compound showed selective antimicrobial activity against
Trichophyton mentagrophytes. The acetone extract of the root bark of E. abyssinica showed radical scavenging activity towards 2,2-diphenyl-1-picrylhydrazyl radical (DPPH). The pterocarpenes, 3-hydroxy-9-methoxy-10-(3,3-dimethylallyl)pterocarpene and erycristagallin, were the most active constituents of the roots of this plant and showing dose-dependent activities similar to that of the standard quercetin.

KEY WORDS: Erythrina abyssinica, Root bark, Leguminosae, Pterocarpan, 8-Methoxyneorautenol,
Pterocarpenes, 3-Hydroxy-9-methoxy-10-(3,3-dimethylallyl)pterocarpene, Erycristagallin, Antimicrobial, Radical scavengers, DPPH

Yenesew A. "Flavonoids and isoflavonoids with anti-plasmodial activities from the roots of Erythrina abyssinica." Planta medica. 2003;69 :658-661. Abstractpaper_33__yenesew_et_al_planta_med_2003.pdf

From the root bark of Erythrina abyssinica a new pterocarpene [3-hydroxy-9-methoxy-10-(3,3-dimethylallyl)pterocarpene] and a new isoflav-3-ene [7,4′-dihydroxy-2′,5′-dimethoxyisoflav-3-ene] were isolated. In addition, the known compounds erycristagallin, licoagrochalcone A, octacosyl ferulate and triacontyl 4-hydroxycinnamate were identified. The structures were determined on the basis of spectroscopic evidence. The crude extract and the flavonoids and isoflavonoids obtained from the roots of this plant showed antiplasmodial activities.

Yenesew A, Endale M, M., Erdelyi, Ekberg A, HM A, Ndakala A, A., Sunnerhagen. "Anthraquinonesof the roots of Pentas micrantha." Molecules . 2013;18,:311-321. Abstractpaper_61_endale_et_al_molecules-2013-18-00311.pdf

Pentas micrantha is used in the East African indigenous medicine to treat malaria. In the first investigation of this plant, the crude methanol root extract showed moderate antiplasmodial activity against the W2- (3.37 μg/mL) and D6-strains (4.00 μg/mL) of Plasmodium falciparum and low cytotoxicity (>450 μg/mL, MCF-7 cell line). Chromatographic separation of the extract yielded nine anthraquinones, of which 5,6-dihydroxylucidin-11-Omethyl ether is new. Isolation of a munjistin derivative from the genus Pentas is reported
here for the first time. The isolated constituents were identified by NMR and mass spectrometric techniques and showed low antiplasmodial activities.

Keywords: anthraquinone; malaria; Pentas micrantha; Rubiaceae; 5,6-dihydroxylucidin-11-O-methyl ether 1.

Yenesew A. "Phytochemical and Antimicrobial Investigation of Girardinia diversifolia (Link) Friis (Urticaceae)." East and Central African Journal of Pharmaceutical Sciences. 2011;14:89-94.njogu_et_al-2011-ecajps.pdf
Yenesew A. "The Antiplasmodial and Radical Scavenging Activities of Flavonoids of Erythrina burttii." Acta Tropica . 2012;123:123-127. Abstract

The acetone extract of the root bark of Erythrina burttii showed in vitro antiplasmodial activity against
the chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum with
IC50 values of 0.97 ± 0.2 and 1.73 ± 0.5 g/ml respectively. The extract also had radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical with an EC50 value of 12.0 g/ml. The isoflav-3-enes burttinol-A and burttinol-C, and the 2-arylbenzofuran derivative burttinol-D were identified as the most active antiplasmodial (IC50 < 10 M) and free radical scavenging (EC50 ca. 10 M) principles. The acetone extract of E. burttii at 800 mg/kg/day, in a 4-day Plasmodium berghei ANKA suppressive test, showed in vivo antimalarial activity with 52% hemosuppression. In the same in vivo test, marginal activities were also
observed for the extracts of the root and stem bark of Erythrina abyssinica and the root bark of Erythrina
sacleuxii.

Yenesew A. "7a-O-Methyldeguelol, a modified rotenoid with an open ring-C, from the roots of Derris trifoliata.." Phytochemistry . 2005;66:653-657. Abstractpaper_36_yenesew_et_al_phyto_2005_66_653.pdf

From the acetone extract of the roots of Derris trifoliata an isoflavonoid derivative, named 7a-O-methyldeguelol, a modified rotenoid with an open ring-C, representing a new sub-class of isoflavonoids (the sub-class is here named as rotenoloid), was isolated and characterised. In addition, the known rotenoids, rotenone, deguelin and a-toxicarol, were identified. The structures were determined on the basis of spectroscopic evidence. Rotenone and deguelin were identified as the larvicidal principles of the acetone extract of the roots of Derris trifoliata.

Yenesew A, Sunnerhagen, P., Erdelyi M, Abdissa N, Induli, M., Fitzpatrick P, Alao JP, Landberg G. "Cytotoxic Quinones from the Roots of Aloe dawei." Molecules. 2014;19,:3264-3273. Abstractpaper_69_abdissa_et_al_molecules_2014.pdf

Seven naphthoquinones and nine anthraquinones were isolated from the roots of Aloe dawei by chromatographic separation. The purified metabolites were identified by NMR and MS analyses. Out of the sixteen quinones, 6-hydroxy-3,5-dimethoxy-2-methyl-1,4-naphthoquinone is a new compound. Two of the isolates, 5,8-dihydroxy-3-methoxy-2-methylnaphthalene-1,4-dione and 1-hydroxy-8-methoxy-3-methylanthraquinone showed high cytotoxic activity (IC₅₀ 1.15 and 4.85 µM) on MCF-7 breast cancer cells, whereas the others showed moderate to low cytotoxic activity against MDA-MB-231 (ER Negative) and MCF-7 (ER Positive) cancer cells.

Yenesew A. "Antimicrobial and Anticancer Carvotacetone Derivativesof Sphaeranthus." Natural Product Communications . 2012;7:1123-1126. Abstractpaper_58_machumi_npc_publication-sphaeranthus_bullatus-2012.pdf

The CH2Cl2-MeOH (1:1) extract of the aerial parts of Sphaeranthus bullatus, an annual herb native to tropical East Africa, showed activity against chloroquine sensitive D6 (IC50 9.7 μg/mL) and chloroquine resistant W2 (IC50 15.0 μg/mL) strains of Plasmodium falciparum. Seventeen secondary metabolites were isolated from the extract through conventional chromatographic techniques and identified using various spectroscopic methods. The compounds were evaluated for their in vitro antiplasmodial, antileishmanial and anticancer activities revealing activity of four carvotacetone derivatives, namely 3-acetoxy-7-hydroxy-5-tigloyloxycarvotacetone (1), 3,7-dihydroxy-5-tigloyloxycarvotacetone (2), 3-acetoxy-5,7-dihydroxycarvotacetone (3) and 3,5,7-trihydroxycarvotacetone
(4); with antiplasmodial IC50 values of 1.40, 0.79, 0.60 and 3.40 μg/mL, respectively, against chloroquine sensitive D6 strains of P. falciparum;
antiplasmodial activity of IC50 2.00, 0.90, 0.68 and 2.80 μg/mL, respectively, against chloroquine resistant W2 strains of P. falciparum; antileishmanial IC50
values of 0.70, 3.00, 0.70 and 17.00 μg/mL, respectively, against the parasite L. donovanii promastigotes, and anticancer activity against human SK-MEL, KB,
BT-549 and SK-OV-3 tumor cells, with IC50 values between <1.1 - 5.3 μg/mL for 1-3. In addition, cytotoxic effects of the active compounds were evaluated against monkey kidney fibroblasts (VERO) and pig kidney epithelial cells (LLC-PK11). The structures of carvotacetone derivatives were determined by 1D and 2D NMR spectroscopy; the absolute stereochemical configuration of 3-acetoxy-7-hydroxy-5-tigloyloxycarvotacetone (1) was determined as 3R, 4R, 5S by circular dichroism, specific rotation, 1H NMR and 2D NMR ROESY and NOESY experiments.

Keywords: Sphaeranthus bullatus, Asteraceae, Antiplasmodial, Antileishmanial, Anticancer, Carvotacetones.

Yenesew A. "Anti-plasmodial activities of flavonoids from Erythrina sacleuxii." Planta Medica . 2006;72:187-189. Abstractpaper_39_andayi_et_al_planta_med.-_2006_antiplasmodial_flavonoids_from_erythrina_sacleuxii.pdf

The acetone extracts of the root bark and stem bark of Erythrina sacleuxii showed antiplasmodial activities against the chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum. Chromatographic separation of the acetone extract of the root bark afforded a new isoflavone, 7-hydroxy-4'-methoxy-3'-prenylisoflavone (trivial name 5-deoxy-3'-prenylbiochanin A) along with known isoflavonoids as the antiplasmodial principles. Flavonoids and isoflavonoids isolated from the stem bark of E. sacleuxii were also tested and showed antiplasmodial activities. The structures were determined on the basis of spectroscopic evidence.

Yenesew A, Twinomuhwezi H, Kabaru JM, Akala HM, Kiremire BT, Heydenreich M, Peter. "Antiplasmodial and larvicidal flavonoids from Derris trifoliata.". 2009.Website
Yenesew A, Irungu BN, Erdélyi M., Orwa, J.A. GFLKMAPG. "Constituents of the roots and leaves of Ekebergia capensis and their potential antiplasmodial and cytotoxic activities." Molecules . 2014;19:14235-14246. Abstractirungu_et_al_molecules-2014-19-14235-v2.pdf

A new triterpenoid, 3-oxo-12β-hydroxy-oleanan-28,13β-olide (1), and six known
triterpenoids 2–7 were isolated from the root bark of Ekebergia capensis, an African
medicinal plant. A limonoid 8 and two glycoflavonoids 9–10 were found in its leaves. The
metabolites were identified by NMR and MS analyses, and their cytotoxicity was evaluated
against the mammalian African monkey kidney (vero), mouse breast cancer (4T1), human
larynx carcinoma (HEp2) and human breast cancer (MDA-MB-231) cell lines. Out of the
isolates, oleanonic acid (2) showed the highest cytotoxicity, i.e., IC50’s of 1.4 and 13.3 μM
against the HEp2 and 4T1 cells, respectively. Motivated by the higher cytotoxicity of the
crude bark extract as compared to the isolates, the interactions of oleanonic acid (2) with five triterpenoids 3–7 were evaluated on vero cells. In an antiplasmodial assay, seven
of the metabolites were observed to possess moderate activity against the D6 and W2
strains of P. falciparum (IC50 27.1–97.1 μM), however with a low selectivity index
(IC50(vero)/IC50(P. falciparum-D6) < 10). The observed moderate antiplasmodial activity
may be due to general cytotoxicity of the isolated triterpenoids.

Keywords: Ekebergia capensis; tritepenoid; antiplasmodial; cytotoxicity; Vero; 4T1;
HEp2; MDA-MB-231; 3-oxo-12β-hydroxy-oleanan-28,13β-olide

Yenesew A. "Vangueria, infausta, root bark: in vivo and in vitro antiplasmodial activity." British Journal of Biomedical Science . 2006; 63,:129-133. Abstractpaper_42_abosi_et_al-2006.pdf

Vangueria infausta burch subsp. infausta (Rubiaceae) produces fruits eaten by humans and animals. The leaf, fruit, stem bark and root bark are used as a remedy for many ailments and the roots are used to treat malaria. In this study, concentrations of fractions of the V. infausta root bark extract that produce 50% inhibition (IC50) are determined using the ability of the extract to inhibit the uptake of [G3H]-hypoxanthine by P. falciparum cultured in vitro. The root bark extract showed antimalarial activity against Plasmodium berghei in mice. It gave a parasite suppression of 73.5% in early infection and a repository effect of 88.7%. One fraction obtained from a chloroform extract gave an IC50 value of 3.8±1.5 μg/mL and 4.5±2.3 μg/mL against D6 and W2 strains of P. falciparum, respectively, and another from the butanol extract gave an IC50 value of 3.9±0.3 μg/mL against the D6 strain. Chloroquine had an IC50 value of 0.016 μg/mL and 0.029 μg/mL against D6 and W2 strains, respectively. The plant showed the presence of flavonoids, coumarins,
tannins, terpenoids, anthraquinones and saponins.

Yenesew A, Atilaw Y, Heydenreich, Ndakala A, Hoseah M, Akala, M Kamau E. "3-Oxo-14α,15α-epoxyschizozygine: A new schizozygane indoline alkaloid from Schizozygia coffaeoides." Phytochemistry Letters . 2014;10:28-31. Abstractpaper_73_atilaw_et_al_phyto_2014.pdf

The stem bark extract of Schizozygia coffaeoides (Apocynaceae) showed moderate antiplasmodial activity (IC50 = 8–12 μg/mL) against the chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum. Chromatographic separation of the extract led to the isolation of a new schizozygane indoline alkaloid, named 3-oxo-14α,15α-epoxyschizozygine. In addition, two dimeric anthraquinones, cassiamin A and cassiamin B, were identified for the first time in the family Apocynaceae. The structures of the isolated compounds were deduced on the basis of spectroscopic evidence. The schizozygane indole alkaloids showed good to moderate antiplasmodial activities (IC50 = 13–52 μМ).

Yenesew A. "Antimicrobial activities of a new schizozygane indoline alkaloid from Schizozygia coffaeoides and the revised structure of isoschizogaline." Journal of Natural Products. 2002;65:566-569. Abstractpaper_28_kariba_et_al_j.nat_._prod._2002.pdf

Extracts from Schizozygia coffaeoides showed antimicrobial activity against fungal and bacterial species. Alkaloids isolated using bioassay-guided fractionation were isoschizogaline, schizogynine, and a new indoline alkaloid, 7,8-dehydro-19beta-hydroxyschizozygine, shown to be the most active antifungal compound. The structure of isoschizagaline, the only active antibacterial, is revised on the basis of NMR analysis.

Yenesew A, Mushibe EK, Induli M, Derese S, Midiwo JO, Kabaru JM, Heydenreich M, Cock A, Peter MG. "7a-O-methyldeguelol, a modified rotenoid with an open ring--C, from the roots of Derris trifoliata." Phytochemistry. 2005;66:653-657.
Yenesew A. "Joziknipholones A and B: The First Dimeric Phenylanthraquinones, from the Roots of Bulbine frutescens." Chem. Eur. J. . 2008; 14:1420-1429. Abstractpaper_45_Bringmann_et_al_joziknipholones.pdf

From the roots of the African plant Bulbine frutescens (Asphodelaceae), two unprecedented novel dimeric
phenylanthraquinones, named joziknipholones A and B, possessing axial and centrochirality, were isolated,
together with six known compounds. Structural elucidation of the new metabolites was achieved by spectroscopic and chiroptical methods, by reductive cleavage of the central bond between the monomeric phenylanthraquinone and -anthrone portions with sodium dithionite, and by quantum chemical CD
calculations. Based on the recently revised absolute axial configuration of the parent phenylanthraquinones, knipholone and knipholone anthrone, the new dimers were attributed to possess the P-configuration (i.e., with the acetyl portions below the anthraquinone plane) at both axes in the case of joziknipholone A, whereas in joziknipholone B, the knipholone part was found to be M-configured. Joziknipholones A and B are active against the chloroquine resistant strain K1 of the malaria pathogen, Plasmodium falciparum, and show moderate activity against murine leukemic lymphoma L5178y cells.

Yenesew A. "A new isoflavone from stem bark of Millettia dura." Bulletin of the Chemical Society of Ethiopia.. 2003;17:113-115. Abstractpaper_31_derese_et_al_bull_chem_soc._ethiopia_2003.pdf

A new isoflavone (7,3’-dimethoxy-4’,5’-methylenedioxyisoflavone) and three known isoflavones [isoerythrinin A 4’-(3-methylbut-2-enyl) ether, isojamaicin and nordurlettone] were isolated from the stem bark of Millettia dura (Leguminosae). The structures were determined by spectroscopic methods.

Yenesew A, Abdissa, N., Ndakala A, Induli, M., Akala, H.M., Heydenrich, M., Midiwo, J.O. "Knipholone Cyclooxanthrone and an Anthraquinone Dimer with Antiplasmodial Activities from the Roots of Kniphofia foliosa." Phytochemistry Letters . 2013;6:241-245. Abstractpaper_62_abdissa_phytol-2013.pdf

A new phenylanthrone, named knipholone cyclooxanthrone and a dimeric anthraquinone, 10-methoxy-
10,70-(chrysophanol anthrone)-chrysophanol were isolated from the roots of Kniphofia foliosa together
with the rare naphthalene glycoside, dianellin. The structures were determined by NMR and mass
spectroscopic techniques. The compounds showed antiplasmodial activities against the chloroquineresistant (W2) and chloroquine-sensitive (D6) strains of Plasmodium falciparum with 10-methoxy-10,70-(chrysophanol anthrone)-chrysophanol being the most active with IC50 values of 1.17 0.12 and 4.07 1.54 mg/ml, respectively.

Yenesew A. "Four Isoflavanones from the stem bark of Platycelphium voënse." Phytochemistry Letters . 2012;5:150-154. Abstractpaper_54_ivan_et_al_phytol-2012.pdf

From the stem bark of Platycelphium voe¨nse (Leguminosae) four new isoflavanones were isolated and
characterized as (S)-5,7-dihydroxy-20,40-dimethoxy-30-(300-methylbut-200-enyl)-isoflavanone (trivial
name platyisoflavanone A), ()-5,7,20-trihydroxy-40-methoxy-30-(300-methylbut-200-enyl)-isoflavanone
(platyisoflavanone B), 5,7-dihydroxy-40-methoxy-200-(2000-hydroxyisopropyl)-dihydrofurano-[400,500:30,20]-
isoflavanone (platyisoflavanone C) and 5,7,20,300-tetrahydroxy-200,200-dimethyldihydropyrano-[500,600:30,40]-isoflavanone (platyisoflavanone D). In addition, the known isoflavanones, sophoraisoflavanone A and glyasperin F; the isoflavone, formononetin; two flavones, kumatakenin and isokaempferide; as well as two triterpenes, betulin and b-amyrin were identified. The structures were elucidated on the basis of spectroscopic evidence. Platyisoflavanone A showed antibacterial activity against Mycobacterium tuberculosis in the microplate alamar blue assay (MABA) with MIC = 23.7 mM, but also showed cytotoxicity (IC50 = 21.1 mM) in the vero cell test.

Yenesew A. "Anti-plasmodial Flavonoids from the roots of Erythrina abyssinica." Phytochemistry. 2004; 65:3029-3032. Abstractpaper_35_yenesew_et_al_phyto_2004-erythrina_abyssinica.pdf

The ethyl acetate extract of the stem bark of Erythrina abyssinica showed anti-plasmodial activity against the chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum with IC50 values of 7.9 ± 1.1 and 5.3 ± 0.7 lg/ml, respectively. From this extract, a new chalcone, 20,3,4,40-tetrahydroxy-5-prenylchalcone (trivial name 5-prenylbutein) and a new flavanone, 40,7-dihydroxy-30-methoxy-50-prenylflavanone (trivial name, 5-deoxyabyssinin II) along with known flavonoids have been isolated as the anti-plasmodial principles. The structures were determined on the basis of spectroscopic evidence.

Yenesew A, Derese, S., Barasa, L., Akala HM, Yusuf, A.O., Kamau E, Heydenreich. "4'-Prenyloxyderrone from the stem bark of Millettia oblata ssp. teitensis and the antiplasmodial activities of isoflavones from some Millettia species." Phytochemistry Letters ,. 2014;8:69-72. Abstractpaper_68_derese_et_al_phyto_2014.pdf

The CH2Cl2/MeOH (1:1) extract of the stem bark of Millettia oblata ssp. teitensis showed antiplasmodial activity (IC50 = 10–12 μg/mL) against the chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum. Chromatographic separation of the extract led to the isolation of a new isoflavone, 4′-prenyloxyderrone (1), together with known isoflavones (8-O-methylretusin, durmillone, maximaisoflavone B, maximaisoflavone H and maximaisoflavone J), a rotenoid (tephrosin) and a triterpene (lupeol). Similar investigation of Millettia leucantha resulted in the identification of the isoflavones afrormosin and wistin, and the flavone chrysin. The identification of these compounds was based on their spectroscopic data. Five of the isoflavones isolated from these plants as well as 11 previously reported compounds from Millettia dura were tested and showed good to moderate antiplasmodial activities (IC50 = 13–53 μM), with the new compound, 4′-prenyloxyderrone, being the most active (IC50 = 13–15 μM).

Yenesew A. "Busseihydroquinones A-D from the Roots of Pentas bussei." Journal of Natural Products. 2012;75 :1299-1304. Abstractpaper_57_endale_et_al_j_nat_prod_2012.pdf

Four new naphthohydroquinones, named busseihydroquinones A−D (1−4), along with a known homoprenylated dihydronaphthoquinone (5), were isolated from the CH2Cl2/MeOH (1:1) extract of the roots of Pentas bussei. Although the genus Pentas is frequently used by traditional healers for the treatment of malaria, only marginal activities against the chloroquine-sensitive (D6) and the chloroquineresistant (W2) strains of Plasmodium falciparum were observed for the crude root extract and the isolated constituents of this plant.

Yenesew A. "Antimicrobial flavonoids from the stem bark of Erythrina burttii." Fitotherapia . 2005;76:469-472. Abstractpaper_38_yenesew_et_al_fito_2005_76_469.pdf

The chloroform extract of the stem bark of Erythrina burttii showed antifungal and antibacterial activities using the disk diffusion method. Flavonoids were identified as the active principles. Activities were observed against fungi and Gram(+) bacteria, but the Gram() bacteria Escherichia coli was resistant.

Yenesew A, Gumuia I, Heydenreich M, Derese S, Okalebo FA, Ndiege IO, Erdelyi M. "Bioactivity of 'Flemingin A' and other Natural Products from the leaves of Flemingia grahamiana.". 2011.yenesew.pdfWebsite
Yenesew A, Bosire CM, Deyou T, Kabaru JM, Kimata DM. "Larvicidal activities of extracts and rotenoids from Millettia usaramensis subspecies usaramensis on Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae)." Journal of Asia-Pacific Entomology . 2014; 17(3):531-535. Abstractpaper_71_bosire_et_al__asia-2014.pdf

The dichloromethane/methanol (1:1) extract of the stem bark of Millettia usaramensis subspecies usaramensis was tested for its larvicidal activity against the 4th instar Aedes aegypti larvae and demonstrated activity with LC50 value of 50.8 ± 0.06 μg/mL at 48 h. Compounds isolated from the extract were also tested for their larvicidal activities, and the rotenoid usararotenoid-A (LC50 4.3 ± 0.8 μg/mL at 48 h) was identified as the most active principle. This compound appears to be the first rotenoid having a trans-B/C ring junction and methylenedioxy group at C-2/C-3 with high larvicidal activity. Related rotenoids with the same configuration at the B/C-ring junction did not show significant activity at 100 μg/mL.

Yenesew A. "Antinocieptive activity of Toddalia asiatica (L) Lam. in models of central and peripheral pain." Phytopharmacology . 2012;3(1):122-129. Abstractpaper_60_kariuki_et_al_phytopharmacology_2012.pdf

Toddalia asiatica within the context of traditional African medicine is a commonly used medicinal plant in East Africa for the management of pain and inflammatory conditions. It is used by the Masai in both Kenya and Tanzania for management of rheumatism among others. The present study was undertaken to investigate the antinociceptive activities of T. asiatica in Swiss albino mice in acetic acid-induced writhing, tail-flick and hot plate pain tests. The extract solvent (vehicle), morphine and aspirin were employed as negative and positive controls respectively. The acetic acid -induced writhing test was used as the screening test and as the root bark extract was found to be more potent than the leaf extract, the former was investigated using the hot plate and the tail flick tests. The root bark extract (200 mg / kg) showed highly significant (p < 0.001) antinociceptive activity in the hot plate and the tail flick tests. The 100mg/kg dose showed significant (p < 0.05) activity in the tail flick test but not significant in the hot plate test. The present study, therefore lends support to the anecdotal evidence for use of T. asiatica in the management of painful conditions.

Yenesew A. "Three ent-trachylobane diterpenes in the leaf exudates of Psiadia punctulata." Phytochemistry. 2006;67,:1322-1325. Abstractpaper_41_juma_et_al_phyto_2006_67_1322.pdf

Three ent-trachylobane diterpenes have been isolated from the leaf exudates of Psiadia punctulata and characterised as 6a,17,19-enttrachylobantriol; 2a,18,19-ent-trachylobantriol; and 2b,6a,18,19-ent-trachylobantetraol. The structures were determined on the basis of spectroscopic evidence.

Yenesew A, Gumula I, Erdélyi M, Patrick. A, J Isaiah Omolo Ndiege PS, Omolo, N, Sunnerhagen P. "Cytotoxic and Antioxidant Flemingins G-P from the Leaves of Flemingia grahamiana." Journal of Natural Products . 2014. Abstractpaper_76_ivan_et_al_jnp_2014_77_2060_2067.pdf

The known flemingins A-C (1-3) and nine new chalcones, named flemingins G-O (4-12), along with deoxyhomoflemingin (13) and emodin (14) were isolated from a leaf extract of Flemingia grahamiana. The isolated chalcones were found to have a geranyl substituent modified into a chromene ring possessing a residual chain, as shown by spectroscopic methods. The leaf extract showed an IC50 value of 5.9 μg/mL in a DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging assay. The chalcones flemingins A, B, C, G, and H were active in the DPPH radical scavenging assay (ED50 4.4-8.9 μM), while flemingins A and C showed cytotoxicity against MCF-7 human breast cancer cells (IC50 8.9 and 7.6 μM, respectively).

Yenesew A. "C-Methylated and C-prenylated isoflavonoids from root extracts of Desmodium uncinatum." Phytochemistry 68, 646-651.. 2007;68(5):646-651. Abstractpaper_44_guchu_et_al_phyto_2007_68_646.pdf

A pterocarpan, 1,9-dihydroxy-3-methoxy-2-methylpterocarpan (named uncinacarpan) and two isoflavanones, 5,7-dihydroxy-2',3',4'-trimethoxy-6-(3-methylbut-2-enyl)isoflavanone (named uncinanone D) and ,4'-dihydroxy-7,2'-dimethoxy-6-methylisoflavanone (named uncinanone E), were isolated from the CH(2)Cl(2) root extract of Desmodium uncinatum (Jacq.) DC and characterised by spectroscopic methods. In addition, a rare pterocarpan edudiol and two known abietane diterpenes, 7-oxo-15-hydroxydehydroabietic acid and 7-hydroxycallitrisic acid were identified. The fraction of the root extract that was analysed induced germination of Striga hermonthica seeds, but none of the isolated compounds showed this activity.

Yenesew A, Judith O, Saffudin D, Catherine L. "Phytochemical screening of Dierama cupuliflorum Klatt. (Iridaceae)." Journal of Pharmacy Research. 2014; 8:589-592. Abstractpaper_72_judith_et_al_jou_of_pharma._res._2014.pdf

Background: Plants continue to play a vital role in their therapeutic value. This is because of the vast secondary metabolites that many of them produce. These natural products have been utilised as single or in combination with other compounds for utilization as source of drugs for many ailments in form of antibacterials, antifungals, antivirals, antihelminthes, and antimalarials among others. Plants evaluated phytochemically in most cases have previous reports on biological activity, ethnomedicinal or traditional medicine usage. However, many other plants with no such previous reports may be as important with variety of natural products with potential significance in pharmaceuticals for drug development. Dierama cupuliflorum is one such plant. The aim of the present study was to investigate the presence of phytochemicals in this plant. Method : The organic solvent extracts from Methanol: Dichloromethane (1:1) along with dry powder/ground portions from corms and aerial parts were screened for the presence of selected phytochemicals using standard chemical procedures. Results: Phytochemical screening revealed the presence of terpenoids, alkaloids, saponins, tannins, flavanoids, glycosides and anthraquinones. More phytochemicals were detected in corms than in the aerial parts. Conclusion: Although there is no available report on the use of this plant for medicinal purposes, the phytochemical data presented here has demonstrated that this plant has the potential to be used significantly for therapeutic purposes in many health challenges. This study has therefore laid down a good foundation for future studies on this plant whose bioactivity studies are currently underway.

Yenesew A. "Antiplasmodial b-hydroxydihydrochalcone from seedpods of Tephrosia elata." Phytochemistry Letters . 2009;2:99-102. Abstractpaper_46_muiva_et_al_phytol-2009.pdf

From the seedpods of Tephrosia elata, a new b-hydroxydihydrochalcone named (S)-elatadihydrochalcone
was isolated. In addition, the known flavonoids obovatachalcone, obovatin, obovatin methyl ether
and deguelin were identified. The structures were determined on the basis of spectroscopic evidence.
The crude extract and the flavonoids obtained from the seedpods of this plant showed antiplasmodial
activities. The literature NMR data on b-hydroxydihydrochalcones is reviewed and the identity of some
of the compounds assigned b-hydroxydihydrochalcone skeleton is questioned.

Yenesew A, Twinomuhwezi H, Kabaru JM, Akala HM, Kirimire B, Heydenreich M, Peters MG, Eyase FL, Waters NC, Walsh DS. "Antiplasmodial and larvicidal flavonoids from Derris trifoliata." Bull. Chem. Soc. Ethiop. 2009;23(3):001-006.
Yenesew A. "Antiplasmodial and larvicidal activities of flavonoids of Derris trifoliata." Bull. Chem. Soc. Ethiopia . 2009;23:409-414. Abstractpaper_48_yenesew_et_al_bull_chem_soc_ethiop-2009-23-409.pdf

From the dichloromethane-methanol (1:1) extract of the seed pods of Derris trifoliata, a new flavanone derivative (S)-lupinifolin 4´-methyl ether was isolated. In addition, the known flavonoids lupinifolin
and rotenone were identified. The structures were determined on the basis of spectroscopic evidence. Lupinfolin showed moderate in vitro antiplasmodial activity against the D6 (chloroquine-sensitive) and W2 (chloroquineresistant) strains of Plasmodium falciparum. The different parts of this plant showed larvicidal activities against Aedes aegypti and rotenoids were identified as the active principles.

KEY WORDS: Derris trifoliata, Leguminosae, Flavanone, (S)-Lupinifolin 4´-methyl ether, Lupinifolin,
Antiplasmodial, Rotenoid, Larvicide, Aedes aegypti

Yenesew A. "Antiplasmodial activities and X-ray crystal structures of rotenoids from the stem bark of Millettia usaramensis subspecies usaramensis." Phytochemistry. 2003;64:773-779. Abstractpaper_34_yenesew_et_al_phyto_2003_64_773.pdf

The dichloromethane extract of the stem bark of Millettia usaramensis subspecies usaramensis showed anti-plasmodial activity against the chloroquine sensitive (D6) and chloroquine resistant (W2) strains of Plasmodium falciparum. Chromatographic separation of the extract led to the identification of a new rotenoid, (6aR,12aS)-2,3-methylenedioxy-9-methoxy-8-(3,3-dimethylallyl)-12ahydroxyrotenoid (trivial name, usararotenoid C) along with known flavonoids (usararotenoid A, 12a-epimillettosin, 6a,12a-dehydromillettone, barbigerone and 40-O-geranylisoliquiritigenin) as the anti-plasmodial principles. The structures were determined by spectroscopic analyses. CD and X-ray analyses established absolute configurations.

Yenesew A, L. K., Omosa, Beatrice, Amugune, Ndunda B, Milugo TKTK, Heydenreich M, Midiwo JO. "Antimicrobial flavonoids and diterpenoids from Dodonaea angustifolia." South African Journal of Botany. . 2014;91, :58-62. Abstractpaper_67_omosa_et_al_south_africa_jou..2014.pdf

The surface exudates of the leaves of Dodonaea angustifolia from Ngong forest population (6 km from Nairobi city center, Kenya) demonstrated antimicrobial activity against Gram-negative (Escherichia coli), Gram-positive (Staphylococcus aureus and Bacillus pumilus) bacteria and the fungus Sacchromyces cerevisiae. Chromatographic separation of the exudates yielded eight methylated flavonoids; 5-hydroxy-3, 4′,7-trimethoxyflavone (1), 3,5-dihydroxy-4′,7-dimethoxyflavone (2), santin (3), kumatakenin (4), rhamnocitrin (5), isokaempferide (6), 3,4′,5,7, tetrahydroxy-6-methoxyflavone (7), pinocembrin (8); two clerodanes, dodonic acid (9) and 2β-hydroxyhardwickiic acid (10) and one labdane; (ent-3β,8α)-15,16-epoxy-13(16),14-labdadiene-3,8-diol (11) diterpenoids. The flavonoid aglycones; 6, 7 and the clerodane diterpenoids; 9 and 10 and labdane diterpenoid, 11 were isolated for the first time from this plant species. The structures of the isolated compounds were identified using ultraviolet (UV), mass spectroscopy (MS), one dimension (1D) and two dimension (2D) nuclear magnetic resonance (NMR) spectroscopy and by comparison of the spectral data with literature. The quercetin derivative, 3,4′,5-trihydroxy-3′,7-dimethoxyflavone (12) showed broad spectrum antibacterial activities against E. coli and B. pumilus with minimum inhibition concentration (MIC) values less than 31.25 μg/well and against S. aureus with MIC below 62.5 μg/well. This compound showed poor antifungal activity against S. cerevisiae (MIC < 500 μg/well). Good antifungal activities were observed for 5,4′-dihydroxy-7-methoxyflavanone (13) and hautriwaic acid lactone (14) against S. cerevisiae with MIC values less than 7.8 μg/well. The most active antifungal compound was 5,7-dihydro-3,4′,6-trimethoxyflavone (3, santin) with an MIC value less than 3.9 μg/well against S. cerevisiae. The rest of the compounds exhibited weak to moderate activities. For comprehensive structure activity relationship studies (SAR), hautriwaic acid lactone (14), hautriwaic acid (15), penduletin (16) isolated from the surface exudates of D. angustifolia from Voi (200 km from Mombasa city center, Kenya) and 12 and 13 from Senecio roseiflorus isolated earlier were included in the bioassays.

Yenesew A. "Phtytochemical evaluation of Kenyan medicinal plants. .". In: The 11th NAPRECA Symposium. Antananarivo, Madagascar; 2005.midiwo_et_al-11th_napreca_proceedings.pdf
Yenesew A. "Naphthoquinones from the roots of Aloe secundiflora (Asphodelaceae)." Phytochemistry Letters . 2012;5:506-509. Abstractpaper_56_induli_et_al_phytol_-2012.pdf

Two new naphthoquinones, 5-hydroxy-3,6-dimethoxy-2-methylnaphthalene-1,4-dione and 5,8-dihydroxy-
3-methoxy-2-methylnaphthalene-1,4-dione, were isolated from the roots of Aloe secundiflora together with the known compounds chrysophanol, helminthosporin, isoxanthorin, ancistroquinone C, aloesaponarins I and II, aloesaponols I and II, laccaic acid D methyl ester and asphodelin. The structures were elucidated based on spectroscopic evidence. This appears to be the first report on the occurrence of naphthoquinones in the genus Aloe. Aloesaponarin I and 5-hydroxy-3,6-dimethoxy-2-methylnaphthalene-1,4-dione showed anti-bacterial activity against Mycobacterium tuberculosis with MIC values of 21–23 mg/mL in the Microplate Alamar Blue Assay (MABA) and Low Oxygen Recovery Assay (LORA); 5-hydroxy-3,6-dimethoxy-2-methylnaphthalene-1,4-dione also showed cytotoxicity against the Vero cell line (IC50 = 10.2 mg/mL)

Yenesew A. "Three dimeric anthracene derivatives from Bulbine abyssinica." Tetrahedron . 2005;61:2667-2674. Abstractpaper_37_wanjohi_et_al_tetra_2005_61_2667.pdf

From the fruits of Bulbine abyssinica three new dimeric anthracene derivatives, (P)-8,9,10,80-tetrahydroxy-3,30-dimethyl[10,70-bianthracene]-1,4,90,100-tetraone (trivial name abyquinone A), (10R)-1,4,8,10,80-pentahydroxy-3,30-dimethyl-[10,70-bianthracene]-9,90,100(10H)-trione (trivial name abyquinone B), and (10R)-30,40-dihydro-1,4,8,30,80,90-hexahydroxy-3,30-dimethyl-[10,70-bianthracene]-9,10(10H,20H)-dione (trivial name abyquinone C) were isolated. Despite their structural differences, these three compounds are connected to each other by the apparently biomimetic conversion of abyquinone
C (a preanthraquinonylanthrone with two stereogenic centers) into
B (an anthraquinonylanthrone with one stereogenic center) and finally into A (an axially chiral bianthraquinone) under mild conditions, involving a highly efficient center-to-axis chirality transfer. In addition, the known anthraquinones islandicin and chrysophanol were identified. The structures were determined on the basis of spectroscopical evidences, chemical transformations, and quantum chemical CD calculations.

Yenesew A, N A, Heydenreich M, Midiwo JO, Ndakala A, Majer Z, Neumann B, Stammler H-G, Sewald N. "8-Hydroxy-6-methylxanthone-1-carboxylic acid and 6',8-O-dimethylknipholone from the roots of Bulbine frutescens." Phytochemistry Letters . 2014;9:67-73. Abstractpaper_70_abdissa_et_al_phyto_2014.pdf

Phytochemical investigation of the dichloromethane/methanol (1:1) extract of the roots of Bulbine frutescens led to the isolation of a new xanthone, 8-hydroxy-6-methylxanthone-1-carboxylic acid (1) and a new phenylanthraquinone, 6′,8-O-dimethylknipholone (2) along with six known compounds. The structures were elucidated on the basis of NMR and MS spectral data analyses. The structure of compound 1 was confirmed through X-ray crystallography which was then used as a reference to propose the revision of the structures of six seco-anthraquinones into xanthones. The isolated compounds were evaluated for cytotoxicity against human cervix carcinoma KB-3-1 cells with the phenylanthraquinone knipholone being the most active (IC50 = 0.43 μM). Two semi-synthetic knipholone derivatives, knipholone Mannich base and knipholone-1,3-oxazine, were prepared and tested for cytotoxic activity; both showed moderate activities (IC50 value of 1.89 and 2.50 μM, respectively).

Yenesew A. "Antinocieptive Activities of the Root Extracts of Rhus natalensis Kraus and Senna singueana." Phytopharmacology . 2012;2:1-6. Abstractpaper_59_karuki_et_al-2012.pdf

Rhus natalensis and Senna singuaenae are traditional African plants commonly used as medicinal plant in East Africa for the management of pain. The plants are used for management of rheumatism among others. This study investigated the antinociceptive activities of R. natalensis and S. singuaenae in Swiss albino mice using the tail-flick and hot plate tests. Extract solvent (vehicle), morphine and aspirin were employed as controls. Root extract of R. natalensis (100 and 200 mg /kg) and 100 mg /kg of S. singuaenae showed no significant antinociceptive activity in the hot plate while the 200mg /kg of S. singuaenae showed significant antinociceptive activity (p<0.05). In the tail flick tests, root extract of R. natalensis (100 and 200 mg / kg) showed highly significant antinociceptive activity (p<0.01) while 200mg / kg of S. singuaenae showed significant antinociceptive activity (p<0.05) compared to the controls. The 100 mg /kg of S. singuaenae showed no significant antinociceptive activity in the tail flick. This study lends support to the anecdotal evidence for use of R. natalensis and S. singuaenae in the management of painful conditions.

Keywords: Rhus natalensis; Senna singuaenae; analgesic; Rhus natalensis; Senna singuaenae; rheumatism

Yenesew A. "Two unusual rotenoid derivatives, 7a-O-methyl-12a-hydroxydeguelol and spiro-13-homo-13-oxaelliptone, from the seeds of Derris trifoliata." Phytochemistry. 2006;67:988-991. Abstractpaper_40_yenesew_et_al_derris-phyto-2006.pdf

The crude methanol extract of the seeds of Derris trifoliata showed potent and dose dependent larvicidal activity against the 2nd instar larvae of Aedes aegypti. From this extract two unusual rotenoid derivatives, a rotenoloid (named 7a-O-methyl-12a-hydroxydeguelol) and a spirohomooxarotenoid (named spiro-13-homo-13-oxaelliptone), were isolated and characterised. In addition a rare natural chromanone (6,7-dimethoxy-4-chromanone) and the known rotenoids rotenone, tephrosin and dehydrodeguelin were identified.
The structures were assigned on the basis of spectroscopic evidence. The larvicidal activity of the crude extract is mainly due to rotenone.

Yenesew A., Dagne E. "Knipholone anthrone from Kniphofia foliosa." Phytochemistry . 1993;34 :1440-1441. Abstractpaper_14_dagne_et_al_phyto_1994_35_401.pdf

A new anthrone named knipholone anthrone was isolated from the stem of Kniphofia foliosa. Its structure was determined by spectral analysis as well as conversion to knipholone.

Yenesew A., Machumi, F. SDMWJTKWVSJ. "Antimicrobial and Antiparasitic Abietane Diterpenoids from the roots of Clerodendrum eriophyllum." Natural Product Communications . 2010;5 :853-858. Abstractpaper_49_machumi_et_al-npc-2010.pdf

Chromatographic separation of the roots of a Kenyan medicinal plant, Clerodendrum eriophyllum, led to the isolation of ten abietane diterpenoids (1-10), one of which (1) was isolated for the first time from a natural source. Using spectroscopic data, the structure of 1 was determined to be 12-hydroxy-8,12-abietadiene-3,11,14-trione. Circular dichroism (CD) spectra showed that the stereochemistry of compounds 1, 3, and 6-8 belongs to the normal series of abietane diterpenes, which confirmed the absolute stereochemistry of the isolated compounds. Compounds 1-10 were evaluated for their in vitro antiplasmodial, antileishmanial, antifungal and antibacterial activities. Compounds 3 and 7 exhibited potent antifungal activity (IC50/MIC 0.58/1.25 and 0.96/2.5 microg/mL, respectively) against C. neoformans, whereas 3, 6 and 7 showed strong antibacterial activity against Staphylococcus aureus and methicillin-resistant S. aureus with IC50/MIC values between 1.33-1.75/2.5-5 and 0.96-1.56/2.5 microg/mL, respectively. In addition, compounds 3 and 9 exhibited potent antileishmanial activity (IC50 0.08 and 0.20 microg/mL, respectively) against L. donovani, while 3 and 7 displayed weak antimalarial activity against Plasmodium falciparum, but 9 was inactive

Yenesew A., Juma, W.P. AEMHOGPWIHMFL. "Terpurinflavone: An Antiplasmodial Flavone from The Stem of Tephrosia purpurea." Phytochemistry Letters .. 2011;4:176-178. Abstractpaper_51_juma_et_al_phytol-2011.pdf

The stem extract of Tephrosia purpurea showed antiplasmodial activity against the D6 (chloroquine-sensitive) and W2 (chloroquine-resistant) strains of Plasmodium falciparum with IC50 values of 10.47 ± 2.22 μg/ml and 12.06 ± 2.54 μg/ml, respectively. A new prenylated flavone, named terpurinflavone, along with the known compounds lanceolatin A, (−)-semiglabrin and lanceolatin B have been isolated from this extract. The new compound, terpurinflavone, showed the highest antiplasmodial activity with IC50 values of 3.12 ± 0.28 μM (D6) and 6.26 ± 2.66 μM (W2). The structures were determined on the basis of spectroscopic evidence.

Yenesew A., and E. Dagne MSMW. "An anthrone, anthraquinone and two oxanthrones from Kniphofia foliosa." Phytochemistry . 1994;37:525-528. Abstractpaper_15_yenesew_et_al_phyto_1994_37_525.pdf

The compounds isoknipholone, isoknipholone anthrone, foliosone and isofoliosone were isolated from the stem of Kniphofia foliosa and their structures determined by spectral analyses. In addition, the known compounds, aloesaponol Ill, aloesaponol III-8-methyl ether and 4,6-dihydroxy-2-methoxyacetophenone were isolated and identified.

Yenesew A., and Dagne DHE. "Isoflavonoids from Taverniera abyssinica." Bulletin of the Chemical Society of Ethiopia. 1987;1: 36-41.paper_2_yenesew_et_al_bull._1987_isoflavonoids_from_taverniera_abyssinica.pdf
Yenesew A., Martha Induli, Meron Gebru NAHAIWRBMHSM. "Antiplasmodial Quinones from the Rhizomes of Kniphofia foliosa." Natural Products Comunications . 2013;8:1261-1264. Abstractpaper_64_induli_et_al-npc-2013.pdf

Extracts of the rhizomes of Kniphofia foliosa exhibited antiplasmodial activities against the chloroquine-sensitive (D6) and chloroquine-resistant (W2) strains of Plasmodium falciparum with IC50 values of 3-5 microg/mL. A phenyloxanthrone, named 10-acetonylknipholone cyclooxanthrone (1) and an anthraquinone-anthrone dimer, chryslandicin 10-methyl ether (2), were isolated from the rhizomes, along with known quinones, including the rare phenylanthraquinone dimers, joziknipholones A and B. The structures of these compounds were determined based on spectroscopic data. This is the second report on the occurrence of the dimeric phenylanthraquinones in nature. In an in vitro antiplasmodial assay of the isolated compounds, activity was observed for phenylanthraquinones, anthraquinone-anthrone dimers and dimeric phenylanthraquinones, with joziknipholone A being the most active. The new compound, 10-acetonylknipholone cyclooxanthrone, also showed anti-plasmodial activity. In an in vivo assay, knipholone anthrone displayed marginal antimalarial activity.

Yenesew A., van B-E. WADE. "Chemotaxonomic significance of anthraquinones in the roots of Asphodeloideae (Aspholdelaceae)." Biochemical Systematics and Ecology. 1995; 23: 277-281. Abstractpaper_18_van_wyk_et_al_biochemical_sys_eco_1995_23_277.pdf

The distribution of seven anthraquinones in the roots of some 46 species belonging to the genera Asphodelus, Asphodeline, Bulbine, Bulbinella and Kniphofia was studied by TLC and HPLC, 1,8-Dihydroxyanthraquinones based on a chrysophanol unit are the main constituents of the subterranean metabolism in the subfamily Asphodeloideae. The genera Bulbine, Bulbinella and Kniphofia elaborate knipholone-type compounds. These compounds appear to be characteristic constituents for the three genera Bulbine, Bulbinella and Kniphofia and support the idea that Kniphofia is not related to the Alooideae.

Yenesew A., and Dagne WAE. "A comparative study of Anthraquinones in rhizomes of some Kniphofia species." Biochemical Systematics and Ecology. 1988; 16 :157-159. Abstractpaper_5_yenesew_et_al_biochemical_sys_eco_1988_16_157.pdf

The anthraquinone content of eight kniphofia species was compared using reversed phase HPLC method coupled with a photodiode array detector.

Yenesew A., E. Dagne WPG. "Flavonoids and isoflavonoids from Tephrosia fulvinervis and Tephrosia pentaphylla." Phytochemistry. 1989;28 :3207-3210. Abstractpaper_8_dagne_et_al_phyto_1989.pdf

From the roots, leaves and pods of Tephrosia pentaphylla three new 6-oxygenated rotenoids (dihydrostemonal, 9-demethyldihydrostemonal and 6-acetoxydihydrostemonal) were isolated and characterized. In addition six known rotenoids (villosin, sumatrol, rotenone, cis-12a-hydroxyrotenone, 6-hydroxyrotenone and α-toxicarol) and the flavanone obovatin were obtained. A similar analysis of the roots of T. fulvinervis yielded only known rotenoids (α-toxicarol, deguelin, munduserone, cis-12a-hydroxymunduserone) and the common pterocarpan (-)-maackiain.

Yenesew A., and J.O. Midiwo HPMMG. "Four isoflavones from stem bark of Erythrina sacleuxii." Phytochemistry . 1998;49 :247-249. Abstractpaper_24_yenesew_et_al_phyto_1998_49_247.pdf

From the stem bark of Erythrina sacleuxii four new isoflavones were isolated and characterized as 5,7-dihydroxy-2′,4′,5′-trimethoxyisoflavone (trivial name, 7-demethylrobustigenin), 5,7-dihydroxy-4′-methoxy3′-(3-methylbut-2-enyl)isoflavone [3′-(3-methylbut-2-enyl)biochanin A], 5,7,3′-trihydroxy-4′-methoxy-5′-(3-methylbut-2-enyl)isoflavone [5′-(3-methylbut-2-enyl)pratensein] and 5,7,3′-trihydroxy-4′-methoxy-5′-formylisoflavone (5′-formylpratensein). The structures were determined on the basis of spectroscopic evidence.

Yenesew A., and E. Dagne, F. Capasso MPNA. "Preliminary Studies on Antipyretic and Analgesic Properties of Taverniera abyssinica." Ethiopian Medical Journal . 1990;28 :155-161. Abstractpaper_11_yenesew_et_al_ethiop._med._1990_taverniera_abyssinca.pdf

In an attempt to ascertain the pharmacological basis of the use of the marketed traditional drug Taverniera abyssinica A. Rich. (Amharic name Dingetegna), crude extracts as well as purified substances of this plant were tested for their antipyretic and analgesic properties. Antipyretic activity was determined on rats made hyperthermic by yeast injection and analgesic activity was determined by the hot plate, as well as the acetic acid induced writhing, methods. The study showed that the plant possesses significant antipyretic and analgesic activities.

Yenesew A., and J.O. Midiwo, M. Heydenreich GPSMMG. "Three isoflav-3-enes and a 2-arylbenzofuran from the root bark of Erythrina burttii." Phytochemistry. 2002;59 :337-341. Abstractpaper_27_yenesew_et_al_phyto_2002_59_337.pdf

From the root bark of Erythrina burttii three isoflav-3-enes, 7,4′-dihydroxy-2′-methoxy-6-(1″,1″-dimethylallyl)isoflav-3-ene (trivial name, burttinol-A), 4′-hydroxy-2′-methoxy-2″,2″-dimethylpyrano[5″,6″:8,7]isoflav-3-ene (trivial name, burttinol-B), 7,4′-dihydroxy-2′-methoxy-8-(3″,3″-dimethylallyl)isoflav-3-ene (trivial name, burttinol-C), and 2-arylbenzofuran, 6,4′-dihydroxy-2′-methoxy-5-(1″,1″-dimethylallyl)-2-arylbenzofuran (trivial name, burttinol-D) were isolated. In addition, the known compounds, abyssinone V-4′-methyl ether, bidwillol A, calopocarpin, erybraedin A, erythrabyssin II, isobavachalcone, phaseollidin and phaseollin were identified. The structures were determined on the basis of spectroscopic evidence.

Yenesew A., Endale, M. AAREDNMWSJPHM. "Antiplasmodial Quinones from Pentas longiflora and Pentas lanceolata." Planta medica . 2012;78:31-35. Abstractpaper_53_endale_et_al_planta_medica_2012-78-31-35.pdf

The dichloromethane/methanol (1 : 1) extracts of the roots of PENTAS LONGIFLORA and PENTAS LANCEOLATA showed low micromolar (IC (50) = 0.9-3 µg/mL) IN VITRO antiplasmodial activity against chloroquine-resistant (W2) and chloroquine-sensitive (D6) strains of PLASMODIUM FALCIPARUM. Chromatographic separation of the extract of PENTAS LONGIFLORA led to the isolation of the pyranonaphthoquinones pentalongin ( 1) and psychorubrin ( 2) with IC (50) values below 1 µg/mL and the naphthalene derivative mollugin ( 3), which showed marginal activity. Similar treatment of PENTAS LANCEOLATA led to the isolation of eight anthraquinones ( 4-11, IC (50) = 5-31 µg/mL) of which one is new (5,6-dihydroxydamnacanthol, 11), while three - nordamnacanthal ( 7), lucidin- ω-methyl ether ( 9), and damnacanthol ( 10) - are reported here for the first time from the genus PENTAS. The compounds were identified by NMR and mass spectroscopic techniques.

Yenesew A., and E. Dagne, S. Asmellash DMSS. "Anthraquinones, pre-anthraquinones and Isoeleutherol in the roots of Aloe species." Phytochemistry . 1994;35:401-406. Abstractpaper_14_dagne_et_al_phyto_1994_35_401.pdf

Comparative TLC analysis of the root extracts of 32 Aloe species showed that chrysophanol, asphodelin, chrysophanol-8-methyl ether, aloechrysone, helminthosporin, aloesaponol III, aloesaponarin I, aloesaponol I, aloesaponarin II, aloesaponol II and laccaic acid D-methyl ester are widely distributed in these plants. Isoeleutherol, which is reported here for the first time as a natural product, occurs only in the Saponariae series of Aloe. The chemotaxonomic implication of the distribution of these compounds for the genus Aloe is discussed.

Yenesew A., and B. Irungu, S. Derese MHPJOMMG. "Two prenylated flavonoids from the stem bark of Erythrina burttii." Phytochemistry . 2003;63:445-448. Abstractpaper_32_yenesew_et_al_phyto_2003_63_445.pdf

From the stem bark of Erythrina burttii, a new isoflavone, 5,2′,4′-trihydroxy-7-methoxy-6-(3-methylbut-2-enyl)isoflavone (trivial name, 7-O-methylluteone) and a new flavanone, 5,7-dihydroxy-4′-methoxy-3′-(3-methylbutadienyl)-5′-(3-methylbut-2-enyl)flavanone (trivial name, burttinonedehydrate) along with three known isoflavonoids (8-prenylluteone, 3-O-methylcalopocarpin and genistein) were isolated. The structures were determined on the basis of spectroscopic evidence.

Yenesew A., Peggoty Mutai, Matthias Heydenreich GTGMKC. "3-Hydroxyisoflavanones from the stem bark of Dalbergia melanoxylon: Isolation, antimycobacterial evaluation and molecular docking studies." Phytochemistry Letters . 2013;6 :671-675. Abstractpaper_65_mutai_et_al_phyto_2013.pdf

Two new 3-hydroxyisoflavanones, (S)-3,4′,5-trihydroxy-2′,7-dimethoxy-3′-prenylisoflavanone (trivial name kenusanone F 7-methyl ether) and (S)-3,5-dihydroxy-2′,7-dimethoxy-2″,2″-dimethylpyrano[5″,6″:3′,4′]isoflavanone (trivial name sophoronol-7-methyl ether) along with two known compounds (dalbergin and formononetin) were isolated from the stem bark of Dalbergia melanoxylon. The structures were elucidated using spectroscopic techniques. Kenusanone F 7-methyl ether showed activity against Mycobacterium tuberculosis, whereas both of the new compounds were inactive against the malaria parasite Plasmodium falciparum at 10 μg/ml. Docking studies showed that the new compounds kenusanone F 7-methyl ether and sophoronol-7-methyl ether have high affinity for the M. tuberculosis drug target INHA.

Yenesew A., and B-E., van Wyk DE. "Chemotaxonomic survey of anthraquinones and pre-anthraquinones in roots of Aloe species." Biochemical Systematics and Ecology . 1995;23:267-275. Abstractpaper_17_van_wyk_et_al_biochemical_sys_eco_1995_23_267.pdf

Root samples from 172 species of Aloe were surveyed by TLC and HPLC for the presence of anthraquinones and pre-anthraquinones. With the exception of the three species of the series Serrulatae, 1,8-Dihydroxyanthraquinones (chrysophanol and asphodelin) were detected in all the species sampled. Compounds derived through the 1-methyl-8-hydroxyanthraquinone pathway, i.e. aloesaponarin I, aloesaponarin II and laccaic acid d-methyl ester, together with their corresponding pre-anthraquinones were detected in 129 species. The results also show that isoeleutherol is a useful chemotaxonomic character for the series Saponarieae.

Yenesew A., and E. Dagne WAIGPG. "The Chemical Systematics of the Rutaceae, Subfamily Toddalioideae in Africa." Biochemical Systematics and Ecology . 1988;16:179-188. Abstractpaper_4_dagne_et_al__biochemical_sys_eco..1988.pdf

A recent investigation of five Ethiopian species of the Rutaceae subfamily Toddalioideae, Teclea nobilis, T. simplicifolia, T. borenensis, Vepris dainellii and V. glomerata has led to the identification of alkaloids of the 2-quinolone, dihydrofuroquinoline, linear pyranoquinoline, furoquinoline and acridone types. The distribution of alkaloids and limonoids among African genera of the Toddalioideae is discussed in relation to their potential importance for an understanding of the systematics of this group of species.

Yenesew A., and Waterman MJOPG. "Four isoflavones from seed pods of Millettia dura." Phytochemistry. 1996;41: 951-955. Abstractpaper_20_yenesew_et_al_phyto_1996_41_951.pdf

Seed pods of Millettia dura yielded four novel isoflavones, which have been characterized as 3-(3,4-dimethoxyphenyl)-6-methoxy-8,8-dimethyl-4H,8H-benzo[1,2-b: 3,4-b′]dipyran-4-one (trivial name, durallone), 6-demethyldurallone, 3-(3,4-dimethoxyphenyl)-8-(3-methylbut-2-enyl)-6-methoxy-7-hydroxybenzopyran-4-one (trivial name, predurallone) and 3-(4-3-methylbut-2-enyloxy)-8,8-dimethyl-4H,8H-benzo[1,2-b: 3,4-b′]dipyran-4-one (trivial name, isoerythrinin-A 4′-(3-methylbut-2-enyl) ether. Structures of these compounds were determined on the basis of their spectroscopic data.

Yenesew A., and Waterman DEPG. "Flavonoids from the seed pods of Tephrosia pumila." Phytochemistry . 1989;28:1291-1292. Abstractpaper_7_yenesew_et_al_phyto_1989.pdf

Inaddition to the known pumilaisoflavones A and B two further isoflavonoids have been isolated from the seed pods of Tephrosia pumila collected in Ethiopia. These have been characterized, on the basis of spectral analysis, as pumilaisoflavone C (5,7,4′-trihydroxy-3′,5′-dimethoxy-6,2′-di(3,3-dimethylallyl)isoflavone) and pumilaisoflavone D (5,4′-dihydroxy-3′,5′-dimethoxy-2″,2″-dimethylpyrano[5″,6″: 6,7]isoflavone).

Yenesew A., and J.O. Midiwo HPMMG. "Two prenylated flavanones from stem bark of Erythrina burttii." Phytochemistry. 1998; 48 :1439-1443. Abstractpaper_23_yenesew_et_al_phyto_1998_48_1439.pdf

From the stem bark of Erythrina burttii, two new flavanones were isolated and characterised as 5,7-dihydroxy-4′-methoxy-3′,5′-di-(3-methylbut-2-enyl)flavanone (trivial name, abyssinone V-4′-methyl ether) and 5,7-dihydroxy-4′-methoxy-3′-(3-hydroxy-3-methylbut-1-enyl)-5′-(3-methylbut-2-enyl)flavanone (trivial name, burttinone). In addition, seven known compounds were identified. Structures were determined on the basis of spectroscopic evidence.

Yenesew A., and B.F. Juma MWJOPG. "Flavones and phenylpropenoids in the surface exudate of Psiadia punctulata." Phytochemistry. 2001;57 :571-574. Abstractpaper_26_juma_et_al_phyto_2001_57_571.pdf

Three flavones, 5,7-dihydroxy-2′,3′,4′,5′-tetramethoxyflavone, 5,4′-dihydroxy-7,2′,3′,5′-tetramethoxyflavone, and 5,7,4′-trihydroxy-2′,3′,5′ -trimethoxyflavone were isolated from the leaf exudate of Psiadia punctulata, together with the previously reported 5-hydroxy-7,2′,3′,4′,5′-pentamethoxyflavone and 5,7,3′-trihydroxy-2′,4′,5′-trimethoxyflavone. The two phenylpropenoids, Z-docosyl-p-coumarate and E-docosyl-p-coumarate were also isolated. The structures were determined on the basis of spectroscopic evidence.

Yenesew A., Omosa, L. K. DMHPSJOM. "Neo-clerodane diterpenes from Dodonaea angustifolia." Phytochemistry Letters . 2010;3: 217-220. Abstractpaper_50_omosa_et_al_phytol-2010.pdf

Phytochemical investigation of the leaf surface exudate of Dodonaea angustifolia L.f. yielded two new neo-clerodane diterpenes, neo-clerodan-3,13-dien-16,15:18,19-diolide (mkapwanin) and 15-methoxy-neo-clerodan-3,13-dien-16,15:18,19-diolide (15-methoxymkapwanin). In addition, ten known compounds were identified. The structures were determined on the basis of spectroscopic evidence. This additional chemical information could contribute towards solving the taxonomical controversy that exists between Dodonaea angustifolia and Dodonaea viscosa Jacq., which are morphologically similar.

Yenesew A., and Duddeck OJAH. "(R)-Prechrysophanol from Aloe graminicola." Phytochemistry . 1993;34 :1442-1444. Abstractpaper_13_yenesew_et_al_phyto_1993.pdf

From the subterranean stem of Aloe graminicola, a new pre-anthraquinone named prechrysophanol was isolated. Chrysophanol, helminthosporin, (R)-aloesaponol I, (R)-aloesaponol II, aloesaponarin I, aloesaponarin II and laccaic acid D methyl ester were also identified.

Yenesew A., Dagne E. "Anthraquinones and the chemotaxonomy of the Asphodelaceae." Pure & Appl. Chem. . 1994;66: 2395-2398. Abstractpaper_16_dagne_et_al_pure__appl_chem-1994.pdf

Phytochemical investigations on three genera of the Asphodelaceae, Aloe, KniphoJla and Bulbine showed that 1-methyl-8-hydroxyanthraquinones and anthrone-C-glycosides are characteristic constituents of the genus Aloe, while knipholone-type compounds distinguish fiiphoja and Bulbine.

Yenesew A., Dagne E. "Alkaloids of Teclea nobilis." Phytochemistry . 1988;27: 651-653. Abstractpaper_3_yenesew_et_al_phyto_1988.pdf

A new furoquinoline alkaloid to which we have assigned the trivial name nobiline, and seven other quinonline alkaloids were isolated and identified from the leaves and fruits of Teclea nobilis, an African medicinal plant.

Yenesew A., and N. Mascolo, A. Pinto DE. "Antipyretic and analgesic studies of the ethanolic extract of Teclea nobilis Delile." Phytotherapy Research. 1988; 2:154-156. Abstractpaper_6_mascolo_et_al_phytotherapy_1988.pdf

The crude ethanol extract of the leaves of an African medicinal plant Teclea nobilis has been studied for its antipyretic, analgesic and anti-inflammatory activities. The extract exhibited marked antipyretic and analgesic activities while it was found to be weakly active against carrageenin oedema.

Yenesew A., and Waterman MJOPG. "Rotenoids, isoflavones and chalcones from the stem bark of Millettia usaramensis subspecies usaramensis.." Phytochemistry. 1998; 47: 295-300. Abstractpaper_22_yenesew_et_al_phyto_1997_47_295.pdf

From the stem bark of Millettia usaramensis subsp. usaramensis four new 12a-hydroxyrotenoids with the unusual trans B/C ring junction ((+)-12a-epimillettosin, (+)-usararotenoid-A, (+)-12-dihydrousararotenoid-A, and (+)-usararotenoid-B), a new α-hydroxydihydrochalcone (α,4,2′-trihydroxy-4′-O-geranyldihydrochalcone), a new isoflavone, (norisojamicin), and a new cinnamyl alcohol derivative (4-O-geranylcinnamyl acetate) have been isolated and characterized. In addition, the known compounds 4′-O-geranylisoliquiritigenin, isoliquiritigenin, barbigerone, jamaicin and maximaisoflavone-G were identified. The structures were determined on the basis of spectroscopic evidence and chemical transformations.

Yenesew A., Atta-Ur-Raman, M. Alam NDHE. "Three Steroidal Alkaloids from Buxus hildebrandtii." Phytochemistry . 1990;29 :1293-1296. Abstractpaper_9_atta-ur-raman_phyto_1990.pdf

From the leaves of Buxus hildebrandtii three new steroidal alkaloids have been isolated and their structures determined by spectroscopic analysis. The following derived names have been suggested for these new alkaloids: O(30)-benzoyl-16-deoxybuxidienine-C, 30-hydroxybuxamine-A and 30-norbuxamine-A. In addition the known alkaloids cyclomicrobuxamine, buxamine-A, cyclobuxoviridine, moenjodaramine, buxamine-C and cyclorolfeine were also isolated.

Yenesew A., and J.O. Midiwo, M. Heydenreich SPDMG. "Two isoflavanones from stem bark of Erythrina sacleuxii." Phytochemistry. 2000; 55: 457-459. Abstractpaper_25_yenesew_et_al_phyto_2000_55_457.pdf

From the stem bark of Erythrina sacleuxii two new isoflavanones, (R)-5,7-dihydroxy-2′,4′,5′-trimethoxyisoflavanone (trivial name, (R)-2,3-dihydro-7-demethylrobustigenin) and (R)-5-hydroxy-2′,4′,5′-trimethoxy-2″,2″-dimethylpyrano[5″,6″:6,7]isoflavanone (trivial name, (R)-saclenone) were isolated. In addition the known compounds shinpterocarpin, 2,3-dehydrokievitone, abyssinone V, abyssinone V-4′-methyl ether, erythrinasinate and 4′-O-methylsigmoidin B were isolated. The structures were determined on the basis of spectroscopic evidence.

Yenesew. A, Derese S, Midiwo JO, Peter MG. New isoflavonoids from the stem bark of Erythrina sacleuxii.; 1999.
Yenesew., B-E., van Wyk DE. "Chemotaxonomic significance of root anthraquinones and pre-anthraquinones in the genus Lomatophyllum (Asphodelacae)." Biochemical Systematics and Ecology. 1995;23 :805-808. Abstractpaper_19_van_wyk_et_al_biochemical_sys_eco_1995_23_805.pdf

The roots of seven species of Lomatophyllum were analysed by TLC and HPLC for the presence of nine different anthraquinones and pre-anthraquinones which are all known to be characteristic constituents of the subterranean metabolism of Aloe. Chrysophanol and asphodelin were detected in all the samples analysed. In addition, the 1-methyl-8-hydroxyanthraquinones aloesaponarin I, aloesaponarin II and laccaic acid d-methyl ester, together with the corersponding pre-anthraquinones were detected in all seven species. The results support the inclusion of Lomatophyllum in Aloe.

Yensew A. "Limitations to Use of Infrared Spectroscopy for Rapid Determination of Carbon-Nitrogen and Wood Density for Tropical Species. Advances in Analytical Chemistry." Advances in Analytical Chemistry . 2013;3(3). Abstractpaper_63_kennedy10.5923.j.aac_.20130303.01.pdf

Infrared (IR) spectroscopy was used as a rapid and non-destructive method to determine, carbon (C), nitrogen (N) and tree wood density.A total of 82 sample cores were scanned in the reflectance mode from 4000 to 400 cm-1 for mid-infrared (MIR) spectra and from 8000 to 4000cm-1 and 11000-4000cm-1 for near infrared (NIR) spectra. The reference values for C and N were measured using combustion method while wood density was calculated using auger method. Calibration equations were developed using partial least-squares and first derivative spectra. Root mean square error (RMSEP) was used to calculate prediction error. Prediction of Cusing MIR spectra gave R2 = 0.59, RMSEP = 0.02; NIR spectra R2 = 0.50, RMSEP = 0.02, whileN prediction usingMIR spectra had R2 = 0.54, RMSEP = 0.22; NIR spectra R2 = 0.48, RMSEP =0.24. Wood density prediction was fair for MIR (R2= 0.79, RMSEP = 0.14); NIR (R2= 0.69, RMSEP = 0.17).Improved predictions using NIR were for extendedspectral range;though accuracies were inferior to MIR. Both MIR and NIR models showed good potentials to be used as rapid and cost effective method of predicting C-N andwood density.

Keywords Infrared Spectroscopy, Partial Least Squares Regression,Carbon, Nitrogen,Wood Density

Yohannis M, Agnes Wausi, Waema T, Hutchinson M. "The Role of ICT Tools in the Access of Climate Information by Rural Communities." Journal of Sustainability, Environment and Peace. 2019;1(2):32-38. AbstractWebsite

ABSTRACT
This paper, seeks to explore how rural communities especially women in Kitui county use
ICT tools to access localized climate information and how Digital Capital facilitates or
impedes the process. Our view is that the continued access to, and use of, ICT tools like
the mobile phone and radios offer diverse opportunities for rural communities to use
timely and relevant climate information to enhance their livelihood strategy. We
hypothesize that rural communities’ use ICT tools such as mobile phones and the
community radios to access localized climate information (weather, seasonal forecasts
and agro-advisories). A household survey of 419 respondents was adopted for data
collection and analysis, guided by the sustainable livelihood framework. The research
findings disclosed that the radios combined with the mobile phone are commonly
available, accessible and cost-effective ICT tools that have played a role in improving
rural women’s access to real-time, relevant climate and agro-advisory information
reducing information asymmetry in rural settings. The study is motivated by the
increasing challenges of climate variability and climate change that are global. Kitui
County has had its share of climate variability and climate change related problems such
as drought which create problems such as food insecurity.

Yohannis MA, Agnes N. Wausi, Hutchinson MJ, Waema TM. "Enhancing Access and Use of Climate Information through ICTs." Journal of Climate Change and Sustainability. 2019;3(1):1-12. AbstractWebsite

Although the role of ICTs in improving human life in Kenya is acknowledged widely, the focus of much
of ICT-related developments has been on human experiences at the level of disease and needs for
communication and mobility. Less obvious is how such technological interventions may be used to
address seemingly abstract yet grave concerns like climate change and its impact on the quality of human
life. This review paper, therefore, shall investigate the different situations where ICTs may be deployed
in relaying packaged and relevant localized climate information that can help rural farmers in Kitui
County, Kenya to make pertinent and timely decisions to improve their productivity and, ultimately, their
livelihoods. We hypothesize that rural communities' use ICT tools such as the mobile phones and the
community radios to access localized climate information (weather, seasonal forecasts, and agroadvisories)
and that livelihood assets and livelihood strategies positively change with the increasing
availability and use of the ICT-based climate information. The idea of the paper presented is to merge
theoretical and applied research outcomes to narrow the gap between the theory of ICTs usage and the
practice of it, while linking it to climate information and enhanced rural livelihood strategies. The review
of this paper shall be captured in social-scientific terms, and shall contribute to knowledge by helping
researchers and policymakers to determine climate information needs of rural ASAL communities,
knowledge on innovations related to ICTs, among others.

Yohannis MA. ICTS As A Bridge Between Climate Information And Livelihood Strategies Among Rural Women In Kitui County, Kenya.; 2019. Abstract

The study was motivated by the increasing challenges of climate variability and climate change, which create problems, such as food insecurity in Kitui County in Kenya. In the current digital age, ICTs are core to all sectors to facilitate access to and enhance efficiency across various services. Although the role of ICTs in improving life in Kenya is widely acknowledged, the focus of most ICT-related developments has been on human experiences at the level of disease and needs for communication and mobility. Less obvious is how such technological interventions may be used to address seemingly abstract yet grave concerns like climate change and its impact on the quality of human life. This study, therefore, investigated the various scenarios where ICTs were deployed in relaying relevant localized climate information to help rural women farmers in Kitui County to make relevant decisions to improve their farm productivity and their livelihoods by extension. The study incorporated an ICT system to the Sustainable Livelihoods Framework (SLF) that consisted of Digital Capital and ICT Tools, thereby improving on the SLF. This modified SLF, mainstreamed ICT-driven climate information and provided the ideal means by which such information was leveraged to ensure enhanced sustainable livelihoods. Gender and Development (GAD) theory, Bourdieu’s ideas of social capital theory, and the Information Needs Assessment Model (INAM) further strengthened the SLF by addressing household power dynamics and climate information relevance in the rural communities. The research drew from emerging variables to demonstrate that regardless of the context in which the SLF was formulated, its versatility makes it the most appropriate tool for such studies in rural Kenya. The specific objectives of this study were threefold: (1) to assess the extent to which rural women access and use ICT tools in the utilization of climate information including weather, seasonal forecasts and agro-advisories; (2) to analyze the extent to which the use of ICT-based climate information by rural women influence maximize access and utilization of livelihood assets; and (3) to examine the livelihood strategies employed with the increasing availability and use of ICT-based climate information. The author adopted a mixed-methods approach for data collection and analysis that was guided by the SLF. Specific methods used, apart from on-desk review, were a household survey of 419 respondents, 14 key informant interviews, and two focus group discussions. The study merged theoretical and applied research outcomes to narrow the gap between the theory and practice of ICTs use while linking it to climate information and enhanced rural livelihood strategies. The outcome from the research findings highlighted the need for interventions to empower rural women in the use of ICT tools in exploiting the full potential of climate information, the need for tailoring modern scientific climate information to local needs, translated into simple formats and the local Kikamba language, the need for complementary services such as affordable credit, insurance, livelihood diversification opportunities and access to livelihood assets that can further strengthen their household resilience to climate variability. The results show that community radios combined with mobile phones are the most accessible and cost-effective ICT tools for rural women’s access to real-time, relevant climate and agro-advisory information. There is evidence that the women’s livelihood strategies have been enhanced which strengthened their livelihood assets, thereby improving their livelihoods under the wider rubric of the sustainable livelihood framework. The contribution to knowledge for this research was an enhanced SLF where the various responses and systematic analysis made the framework relevant in gaining insights into the link between climate information and livelihood strategies through ICTs among women in ii rural communities in Kitui. The modified framework and the research findings are also timely in light of the increasing realization of ICTs potential in contributing to climate change adaptation and mitigation. Also, the thesis builds on the growing body of literature that generated a rich repository that other researchers can use to advance knowledge, and the outcomes are eight peer-reviewed articles. The output of this study is replicable to other counties in Kenya because rural households depend on agriculture for their livelihood and this economic sector is not exempt to climate change and variability necessitating the need for local specific climate information. The recommendations to the research are that it can be extended to examine outcomes that will look at improved income, sustainable resource utilization, and food security, physical and emotional wellbeing. Further we provide policy recommendations and made suggestions to shape future climate change adaptation policies, plans, and strategies in Kenya that integrates gender equality into ICT and climate change to help farmers adapt to climate change/variability for sustainable development. Keywords: ICT Tools; Digital Capital; Climate Information; Enhanced Sustainable livelihood Framework; Livelihood Strategies

Yole DS, Obanda VO, Kithome K, Ochanda H. "The effect of vaccinating S. mansoni-infected BALB\c mice either before or after treatment. ." African Journal of Health Sciences . 2005;12:65-77.
Yoon DH, Ochieng JW, Lee HK, Oh SJ, Cho BW, Cheong IC, Hanotte O. Genetic diversity and relationships of three Eastern Asian cattle breeds.; 2002. AbstractBook

Ten cattle populations, 3 Asian (Hanwoo, Yanbian, Wagyu), 2 African, and 2 European Bos taurus as well as 2 Asian B. indicus and one Bali cattle, B. banteng, were characterized with 13 microsatellite markers. A total of 364 animals from the different cattle populations were used in the study. Allele frequencies were used to estimate expected heterozygosities (He), genetic distances (Ds), and to perform principal component analysis. 165 alleles were observed across all loci. The data supported a common origin for the Hanwoo and Yanbian cattle (Ds=0.013). No evidence for a major West European taurine introgression into the Wagyu was observed. The Eastern Asian cattle were found to be genetically distinct from the European and African taurine and from the Asian zebu. It is recommended that the genetic uniqueness of these cattle breeds be maintained in conservation and improvement programmes

Yoshimura F, Suzuki T. "Calcium-stimulated adenosine triphosphatase in the microsomal fraction of tooth germ from porcine fetus." Biochim. Biophys. Acta. 1975;410(1):167-77. Abstract

The characterization and localization of a Ca(2+)-ATPase (ATP phosphohydrolase, EC 3.6.1.3) in the tooth germ of the porcine fetus are reported. This enzyme, a microsome fraction, is preferentially activated by Ca(2+). In the presence of 0.5 mM ATP, maximal enzyme activity is obtained at 0.5--1.0 mM CaCl2. The maximal rate of ATP hydrolysis is approx. 20 mumol per h per mg of protein as the enzyme preparation is used here. At optimal Ca(2+) concentration, the Mg(2+) has an inhibitory effect. The enzyme does not require Na+ or/and K+ for activation by Ca(2+). Other nucleotide triphosphates may serve as the substrate, but V for ATP is the highest. The Km for ATP is 8.85 - 10(-5) M. The optimal pH for Ca(2+) activation of the enzyme lies around 9.2. Well known inhibitors of (Na+ + K+)-ATPase, mitochondria ATPase and Ca(2+)-ATPase in the erthrocyte do not inhibit the enzyme. In the subcellular order the enzyme may be assumed to be localized in the smooth endoplasmic reticulum fraction containing cell and Golgi body membrane fragments and in the tissue order in the enamel organ containing an ameloblast layer, stratum intermedium and stellate reticulum.

Yoshizaki M, Ramke J, Furtado JM, Burn H, Gichuhi S, Gordon I, Aghaji A, Marques AP, Dean WH, Congdon N, Buchan J, Burton MJ. "Interventions to improve the quality of cataract services: protocol for a global scoping review." BMJ Open. 2020;10(8):e036413. AbstractWebsite

Cataract is the leading cause of blindness globally and a major cause of vision impairment. Cataract surgery is an efficacious intervention that usually restores vision. Although it is one of the most commonly conducted surgical interventions worldwide, good quality services (from being detected with operable cataract to undergoing surgery and receiving postoperative care) are not universally accessible. Poor quality understandably reduces the willingness of people with operable cataract to undergo surgery. Therefore, it is critical to improve the quality of care to subsequently reduce vision loss from cataract. This scoping review aims to summarise the nature and extent of the published literature on interventions to improve the quality of services for primary age-related cataract globally.

Young AS, Ochanda H, Perry BD, Morzaria SP, Dolan TT, Medley GF, Gettinby G. The biology of the transmission dynamics of Theileria parva. . Nairobi, Kenya: International Society for Veterinary Epidemiology and Economics.; 1994.
Young AS, Shaw MK, Ochanda H, Morzaria SP, Dolan TT. Factors affecting the transmission of African Theileria species of cattle by ixodid ticks. . Saint Paul, Minnesota, USA: University of Minnesota College of Agriculture; 1992.
Young MR, Adera F, Mehta SD, Jaoko W, Adipo T, Badia J, Nordstrom SK, Irwin TE, Ongong'a D, Bailey RC. "Factors Associated with Preference for Early Infant Male Circumcision Among a Representative Sample of Parents in Homa Bay County, Western Kenya." AIDS Behav. 2016. Abstract

Several countries scaling-up adult medical male circumcision (MMC) for HIV prevention intend to introduce early infant male circumcision (EIMC). To assess preference for EIMC in a community with a mature adult MMC program, we conducted a cross-sectional survey of a representative sample of mothers (n = 613) and fathers (n = 430) of baby boys ("index son") at 16 health facilities in western Kenya. Most (59 %) were for EIMC, generally. Just 29 % were for circumcising the index son. Pain and protection from HIV were the most frequently cited barrier and facilitator to EIMC, respectively. In multivariable logistic regression, ever talking with the partner about EIMC and positive serostatus were associated with preference for EIMC for the index son. Attitudes towards EIMC are favorable. Willingness to circumcise an infant son is modest. To facilitate EIMC uptake, education about EIMC pain management and encouraging discussion between parents about EIMC during pregnancy should be integrated into programs.

Young AS, Dolan TT, Mwakima FN, Ochanda H, Mwaura SN, Njihia GM, Muthoni MW, Dolan RB. "Estimation of heritability of susceptibility to infection with Theileria parva in the tick Rhipicephalus appendiculatus." Parasitology. 1995;111:31-38.
Young AH, Wasunna A. "Wrestling with the limits of law: regulating new reproductive technologies." Health Law J. 1998;6 Spec No:239-77.
Yu P-F, Hu Z-H, Wang X-B, Guo J-M, Cheng X-D, Zhang Y-L, Xu Q. "Solid pseudopapillary tumor of the pancreas: a review of 553 cases in {Chinese} literature." World journal of gastroenterology: WJG. 2010;16:1209. AbstractWebsite
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Yuga ME, Kimani, P.M; Kimani JM, Kimani PM, Olubayo MF, Muthomi JW, Nzuve FM. "Combining Ability and Heterosis for Agronomic and Yield Traits in Indica and Japonica Rice Crosses." Journal of Agricultural Science . 2018;10(12):92-103.
YUKO- DRJOWICHRISTINEA. "Study of the prevelenceof bacterial sepsis in preterm neonates presenting with respiratory distress in the Newborn unit , Kenyatta National Hospital. A dessertation being part of the fulfillment of the M_Med programme U.N.O June 1990.". In: A dessertation being part of the fulfillment of the M_Med programme U.N.O. uon press; 1990. Abstract
Faculty of Medicine, College of Health Sciences, University of Nairobi, Kenya. Percutaneous transluminal baloon valvuloplasty is currently the treatment of choice for most cases of pulmonary valve stenosis. In the first series of cases performed at Kenyatta National Hospital, six patients aged 4 to 24 years with severe pulmonary valve stenosis and no other associated cardiac lesions were selected for the procedure. Immediately following baloon valvuloplasty, the pressure gradients across pulmonary valve measured by both echo-Doppler technique and cardiac catheterisation dropped very significantly (P < 0.001). Catheterisation peak systolic gradients (psg) dropped from 162.5 +/- 23.7 to 56.5 +/- 19.0 while echo-Doppler pressure gradients dropped from 112.0 +/- 11.9 to 42.8 +/- 16.0. No complications occurred during or after the procedure. This initial short-term experience in our set-up confirms the safety and effectiveness of this procedure. Furthermore, this procedure is much cheaper and technically easier to perform than cardiac surgery. PMID: 8062769 [PubMed - indexed for MEDLINE]
YUKO- DRJOWICHRISTINEA. "Joshi, Micheal Mugo, Jean Kachner,Lucio Parenzan.Journal of catherterization and cardiovascular diagnosis.36;189-193 1995.". In: Journal of catherterization and cardiovascular diagnosis.36;189-193 1995. uon press; 1995. Abstract
OBJECTIVE: To determine efficacy and safety of the new multi-track catheter system for percutaneous baloon mitral valvotomy. DESIGN: Open, non-randomised intervention. SETTING: Cardiac catheterisation Laboratories of Mater Misericordiae Hospital (1997) and Kenyatta National Hospital, Nairobi(1994). PATIENTS: Twenty four consecutive patients with symptomatic severe pure mitral stenosis (less than 2+ mitral regurgitation) and suitable mitral valve apparatus(leaflets, chordae and papillary muscles) for successful commissurotomy. INTERVENTION: Percutaneous mitral baloon valvotomy under local anaesthesia. Standard left and right heart catheterisation for mitral valve disease. Transeptal left atrial entry using standard septal puncture technique and left ventricle position secured by single long-stiff guide-wire. Double-baloon mitral valvotomy on single guide-wire using multi-track baloon catheters. MAIN OUTCOME MEASURES: Mitral valve area, left atrial pressures, mitral regurgitation grade. RESULTS: Mitral valve area increased from 0.65 +/- 0.15cm2 to 1.98 +/- 0.34cm2 (P < 0.01), left atrial pressures from 30.5 +/- 9.1 to 11.9 +/- 5.1mmHg (P < 0.01). No significant change in mitral regurgitation grades. No complications related to multi-track technique. CONCLUSION: Percutaneous baloon mitral valvotomy using the multi track technique is effective and safe.
YUKO- DRJOWICHRISTINEA. "Percutaneous Balloon mitral valvotomy using multritrack technique, initial experience in Kenya. Yonga G. O, Bonhoeffer P, Jowi C. EAMJ, Vol 76, no 2 1999.". In: EAMJ, Vol 76. uon press; 1999. Abstract
Department of Paediatrics and Child Health, College of Health Sciences, University of Nairobi, P.O. Box 19676-00202 Nairobi, Kenya. OBJECTIVE: To describe the echocardiographic features of children with rheumatic heart disease seen at the Kenyatta National Hospital. DESIGN: A retrospective study. SETTING: The Kenyatta National Hospital Heart Unit. SUBJECTS: Patients aged 20 years and less with echocardiographic diagnosis of rheumatic heart disease. RESULTS: Two hundred and twenty four echocardiograms were analysed. Seventy six point four of cases were aged between 5 and 15 years, while on 3% were less than five years. The combinations mitral and aortic regurgitation was the most common lesion followed by isolated mitral regurgitation. Isolated aortic regurgitation was as rare as isolated mitral stenosis in the paediatric age group 1.8% and 2.7% respectively. When seen in the younger age group, the leaflet morphology in mitral regurgitation was predominantly thickening and clubbing of the leaflets while in the older children the pathology was of marked fibrosis of the sub-valvular apparatus. Leaflet prolapse and commissural fusion was the major pathology in aortic regurgitation. Pulmonary hypertension was the most common complication commonly seen in mitral valve disease. Calcification was a rare encounter in this age bracket. CONCLUSIONS: Rheumatic heart disease in the paediatric age commonly presents as isolated mitral regurgitation or in combinations of mitral and aortic regurgitation. The complications of pulmonary hypertension was predominant in mitral valve disease. Valvular calcification is rare in juvenile rheumatic heart disease. PMID: 16450679 [PubMed - indexed for MEDLINE]
YUKO- DRJOWICHRISTINEA. "Mitral dilatation with the Multi-Track system: an alternative approach.1: Cathet Cardiovasc Diagn. 1995 Oct;36(2):189-93.". In: Cathet Cardiovasc Diagn. 1995. uon press; 1995. Abstract
We developed a simple and versatile new technique (Multi-Track) for percutaneous mitral valvotomy using two two separate balloon catheters positioned on a single guidewire. The first catheter, with only a distal guidewire lumen and a proximal balloon, is introduced over the guidewire into the vein and then advanced into the mitral valve orifice. Subsequently, a normal balloon catheter running on the same guidewire is inserted and lined up with the first catheter so the two are positioned side by side. The balloons are then inflated simultaneously. The technique was applied in 12 patients between 10 and 44 years of age (mean, 27.1) and weighing 24-80 kg (mean, 50.3). Valve area increased from 0.66 cm2 (range, 0.3-0.9 cm2) to 1.97 cm2 (range, 1.3-3.1 cm2) and mean left atrial pressure dropped from 31 mmHg (range, 18-52 mmHg) to 12 mmHg (range, 5-22 mmHg). Mitral dilatation with the Multi-Track system gives results comparable to those with previously described techniques and uses simpler and less costly catheters.
YUKO- DRJOWICHRISTINEA. "The effects of Percutaneous balloon mitral Valvotomy on pulmonary venous flow. Yonga G, Bonhoeffer P, Jowi C. EAMJ, Vol 76, No 1 , Page 28 ,1999.". In: EAMJ, Vol 76, No 1 , Page 28. uon press; 1999. Abstract
OBJECTIVE: To study the effect of percutaneous balloon mitral valvotomy (PBMV) on the deranged systolic and diastolic pulmonary venous flows in mitral stenosis. DESIGN: Open, non-randomised, case-control study. SETTING: Mater Misericordiae Cardiac Catheterisation Laboratory and Kenyatta National Hospital Cardiac Catheterisation Laboratory. PATIENTS: Twelve consecutive patients with severe symptomatic mitral stenosis with valve characteristics suitable for PBMV on echocardiographic evaluation. INTERVENTION: Percutaneous baloon mitral valvotomy. MAIN OUTCOME MEASURES: Peak systolic and diastolic pulmonary flow velocities and velocity time integrals (VTI). RESULTS: Peak sytolic pulmonary flow velocity increased from 29.8 +/- 9.6 to 46.1 +/- 8.5 cm/s p < 0.01) and systolic VTI from 2.6 +/- 1.0 to 5.5 +/- 0.9 cm (p < 0.01). Peak diastolic flow velocity increased from 39.3 +/- 5.7 to 43.0 +/- 6.9 cm/s (p < 0.05) and diastolic VTI from 3.9 +/- 1.5 to 4.8 +/- 1.6 cm (p < 0.05). Mean mitral valve area increased from 0.65 +/- 0.15 to 1.98 +/- 0.34 cm2 (p < 0.001) and mean left atrial pressures from 30.5 +/- 9.1 to 11.9 +/- 5.1 mmHg (p < 0.001). CONCLUSIONS: In patients with severe mitral stenosis and sinus rythm, left atrial filling is biphasic with diastolic preponderance. Successful PBMV causes predominant increase in atrial systolic filling.
YUKO- DRJOWICHRISTINEA. "Echocardiographic patterns of juvenile rheumatic heart disease at the Kenyatta National Hospital, Nairobi. East Afr Med J . 2005 Oct; 82 ( 10 ): 514-9 . PMID: 16450679 [PubMed - indexed for MEDLINE] Yuko-Jowi C, Bakari M.". In: East Afr Med J . 2005 Oct; 82 ( 10 ): 514-9 . uon press; 2005. Abstract
Department of Paediatrics and Child Health, College of Health Sciences, University of Nairobi, P.O. Box 19676-00202 Nairobi, Kenya. OBJECTIVE: To describe the echocardiographic features of children with rheumatic heart disease seen at the Kenyatta National Hospital. DESIGN: A retrospective study. SETTING: The Kenyatta National Hospital Heart Unit. SUBJECTS: Patients aged 20 years and less with echocardiographic diagnosis of rheumatic heart disease. RESULTS: Two hundred and twenty four echocardiograms were analysed. Seventy six point four of cases were aged between 5 and 15 years, while on 3% were less than five years. The combinations mitral and aortic regurgitation was the most common lesion followed by isolated mitral regurgitation. Isolated aortic regurgitation was as rare as isolated mitral stenosis in the paediatric age group 1.8% and 2.7% respectively. When seen in the younger age group, the leaflet morphology in mitral regurgitation was predominantly thickening and clubbing of the leaflets while in the older children the pathology was of marked fibrosis of the sub-valvular apparatus. Leaflet prolapse and commissural fusion was the major pathology in aortic regurgitation. Pulmonary hypertension was the most common complication commonly seen in mitral valve disease. Calcification was a rare encounter in this age bracket. CONCLUSIONS: Rheumatic heart disease in the paediatric age commonly presents as isolated mitral regurgitation or in combinations of mitral and aortic regurgitation. The complications of pulmonary hypertension was predominant in mitral valve disease. Valvular calcification is rare in juvenile rheumatic heart disease. PMID: 16450679 [PubMed - indexed for MEDLINE]
YUKO- DRJOWICHRISTINEA. "Percutaneous transluminal balloon valvuloplasty for pulmonary valve stenosis: report on six cases. East Afr Med J . 1994 Apr; 71 ( 4 ): 232-5 . PMID: 8062769 [PubMed - indexed for MEDLINE] Yonga GO, Bonhoeffer P, Yuko-Jowi C, Shori A, Aseso H.". In: East Afr Med J . 1994 Apr; 71 ( 4 ): 232-5 . uon press; 1994. Abstract
Faculty of Medicine, College of Health Sciences, University of Nairobi, Kenya. Percutaneous transluminal baloon valvuloplasty is currently the treatment of choice for most cases of pulmonary valve stenosis. In the first series of cases performed at Kenyatta National Hospital, six patients aged 4 to 24 years with severe pulmonary valve stenosis and no other associated cardiac lesions were selected for the procedure. Immediately following baloon valvuloplasty, the pressure gradients across pulmonary valve measured by both echo-Doppler technique and cardiac catheterisation dropped very significantly (P < 0.001). Catheterisation peak systolic gradients (psg) dropped from 162.5 +/- 23.7 to 56.5 +/- 19.0 while echo-Doppler pressure gradients dropped from 112.0 +/- 11.9 to 42.8 +/- 16.0. No complications occurred during or after the procedure. This initial short-term experience in our set-up confirms the safety and effectiveness of this procedure. Furthermore, this procedure is much cheaper and technically easier to perform than cardiac surgery. PMID: 8062769 [PubMed - indexed for MEDLINE]
YUKO- DRJOWICHRISTINEA. "Percutaneous balloon mitral valvotomy: initial experience in Nairobi using a new multi-track catheter system.1: East Afr Med J. 1999 Feb;76(2):71-4.". In: East Afr Med J. 1999. uon press; 1999. Abstract
OBJECTIVE: To determine efficacy and safety of the new multi-track catheter system for percutaneous baloon mitral valvotomy. DESIGN: Open, non-randomised intervention. SETTING: Cardiac catheterisation Laboratories of Mater Misericordiae Hospital (1997) and Kenyatta National Hospital, Nairobi(1994). PATIENTS: Twenty four consecutive patients with symptomatic severe pure mitral stenosis (less than 2+ mitral regurgitation) and suitable mitral valve apparatus(leaflets, chordae and papillary muscles) for successful commissurotomy. INTERVENTION: Percutaneous mitral baloon valvotomy under local anaesthesia. Standard left and right heart catheterisation for mitral valve disease. Transeptal left atrial entry using standard septal puncture technique and left ventricle position secured by single long-stiff guide-wire. Double-baloon mitral valvotomy on single guide-wire using multi-track baloon catheters. MAIN OUTCOME MEASURES: Mitral valve area, left atrial pressures, mitral regurgitation grade. RESULTS: Mitral valve area increased from 0.65 +/- 0.15cm2 to 1.98 +/- 0.34cm2 (P < 0.01), left atrial pressures from 30.5 +/- 9.1 to 11.9 +/- 5.1mmHg (P < 0.01). No significant change in mitral regurgitation grades. No complications related to multi-track technique. CONCLUSION: Percutaneous baloon mitral valvotomy using the multi track technique is effective and safe.
YUKO- DRJOWICHRISTINEA, E DRSIMIYUMAJORD. "C. Yuko-Jowi, DE Simiyu, RN Musoke : Ectopia cordis : a report of two cases East Afr Med J 81:486-498; 2004.". In: a report of two cases East Afr Med J 81:486-498; 2004. uon press; 2004. Abstract
Department of Paediatrics and Child Health, College of Health Sciences, University of Nairobi, P.O. Box 19676-00202 Nairobi, Kenya. OBJECTIVE: To describe the echocardiographic features of children with rheumatic heart disease seen at the Kenyatta National Hospital. DESIGN: A retrospective study. SETTING: The Kenyatta National Hospital Heart Unit. SUBJECTS: Patients aged 20 years and less with echocardiographic diagnosis of rheumatic heart disease. RESULTS: Two hundred and twenty four echocardiograms were analysed. Seventy six point four of cases were aged between 5 and 15 years, while on 3% were less than five years. The combinations mitral and aortic regurgitation was the most common lesion followed by isolated mitral regurgitation. Isolated aortic regurgitation was as rare as isolated mitral stenosis in the paediatric age group 1.8% and 2.7% respectively. When seen in the younger age group, the leaflet morphology in mitral regurgitation was predominantly thickening and clubbing of the leaflets while in the older children the pathology was of marked fibrosis of the sub-valvular apparatus. Leaflet prolapse and commissural fusion was the major pathology in aortic regurgitation. Pulmonary hypertension was the most common complication commonly seen in mitral valve disease. Calcification was a rare encounter in this age bracket. CONCLUSIONS: Rheumatic heart disease in the paediatric age commonly presents as isolated mitral regurgitation or in combinations of mitral and aortic regurgitation. The complications of pulmonary hypertension was predominant in mitral valve disease. Valvular calcification is rare in juvenile rheumatic heart disease. PMID: 16450679 [PubMed - indexed for MEDLINE]
Yuko-Jowi C, Mukhwana R, Onyango FE. "Multifocal pheochromocytoma in early childhood: case report." East Afr Med J. 2010;87(6):269-72. Abstract

A three and a half year old male with multifocal phaeochromocytoma involving the right adrenal gland and an intrathoracic mass is presented. Twenty four hour vanillylmandelic acid (VMA) was negative despite suggestive symptomatology. The diagnosis was made on serial CT scans of the head, thoracic inlet and pelvis. He underwent right adrenalectomy and thoracotomy to remove the abdominal and intrathoracic mass. The diagnosis was confirmed by histology. He remained hypertensive on hefty antihypertensive doses throughout his lifespan and finally succumbed to status epilepticus at the age of ten, six years from the time of diagnosis.

Yuko-Jowi C, Mukhwana R, FE. O. "Multifocal pheochromocytoma in early childhood: case report." East Afr Med J. 2010 Jun;87(6):269-72.. 2010. Abstract

Abstract

A three and a half year old male with multifocal phaeochromocytoma involving the right adrenal gland and an intrathoracic mass is presented. Twenty four hour vanillylmandelic acid (VMA) was negative despite suggestive symptomatology. The diagnosis was made on serial CT scans of the head, thoracic inlet and pelvis. He underwent right adrenalectomy and thoracotomy to remove the abdominal and intrathoracic mass. The diagnosis was confirmed by histology. He remained hypertensive on hefty antihypertensive doses throughout his lifespan and finally succumbed to status epilepticus at the age of ten, six years from the time of diagnosis.

PMID:
23057270
[PubMed - indexed for MEDLINE]

Yumbya P, Hutchinson M, Ambuko J, Owino W. "Effect of Hexanal as a Post-harvest Treatment to Extend the Shelf-life of Banana Fruits (Musa acuminata var. Sweet Banana) in Kenya." International Journal of Plant & Soil Science. 2019;29(21-16):1-16.absract.pdf
Yumbya PM, Hutchinson MJ, Ambuko J, Owino WO, Sullivan A, Paliyath G, Subramanian J. "Efficacy of hexanal application on the post-harvest shelf life and quality of banana fruits (Musa acuminata) in Kenya." Tropical Agriculture. 2018;95(1):14-35.abstract.pdf
Yumbya P, Hutchinson M, Ambuko J, Owino W. "Effect of Hexanal as a Post-harvest Treatment to Extend the Shelf-life of Banana Fruits (Musa acuminata var. Sweet Banana) in Kenya." International Journal of Plant & Soil Science. 2019;29(21-16):1-16.absract.pdf
Yumbya P, Ambuko J, Shibairo S, Owino W. "Effect of Modified Atmosphere Packaging (MAP) on the Shelf Life and Postharvest Quality of Purple Passion Fruit (Passiflora Edulis Sims)." Journal of Post-Harvest Technology. 2014;2:25-36. Abstract
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Yusuf AO, Gitu PM, Bhatt BM, Njogu M, Salim A, Orata D. "Solid-Phase Peptide Synthesis of Arginine-vasopressin With Amide Side chain of Asparagine Protected With 1-Tetralinyl Group." Journal of Chemistry & Materials Research. 2014;6(4):60-65.cmr_spps_arg_vaso.pdf
Yusuf A, Gitu P, Bhatt B, Njogu M, Salim A, Orata D. "1-Tetralinyl as Carboxamide-Protecting Group for Asparagine and Application to N-α-t-Butyloxycarbonyl (Boc) Solid-phase Peptide Synthesis of Oxytocin." chemistry and materials research. 2014;6(2). Abstractchemistry and materials research

Description
Oxytocin, a nonapeptide amide, was synthesized on a benzhydryl-resin using the Boc strategy. Benzyl group was used in the protection of sulfhydryl group of cysteine and tyrosine side-chain. Benzhydryl and tetralinyl groups were used in the protection of glutamine and asparagine side-chains respectively. TFMSA-TFA-thioanisole-1, 2-ethanedithiol (2: 20: 2: 1 v/v) was used on the peptide-resin under different cleavage conditions to obtain oxytocin in a one-pot reaction. The cleavage at 40 C for two hours gave oxytocin quantitatively. Oxytocin could be isolated in 56% yield.

Yusuf A, Gitu P, Bhatt B, Njogu M, Salim A, Orata D. "Solid-Phase Peptide Synthesis of Arginine-vasopressin with Amide Side-chain of Asparagine Protected with 1-Tetralinyl Group." Chemistry and Materials Research. 2014;6(4):60.scan0010.pdf
Yusuf A, Gitu P, Bhatt B, Njogu M, Salim A, Orata D. "Solid-Phase Peptide Synthesis of Arginine-vasopressin with Amide Side-chain of Asparagine Protected with 1-Tetralinyl Group." Chemistry and Materials Research. 2014;6(4). AbstractChemistry and Materials Research

Description
Arginine-vasopressin, a nonapeptide amide, was synthesized on a benzhydryl-resin using the Boc-strategy. Benzyl group was used in the protection of sulfhydryl group of cysteine and tyrosine side-chain. Benzhydryl, tetralinyl and tosyl groups were used in the protection of glutamine, asparagine and arginine side-chains respectively. TFMSATFA-thioanisole-1, 2-ethanedithiol (2: 20: 2: 1 v/v) was used to cleave the peptide from the resin under different conditions to obtain arginine-vasopressin in a one-pot reaction. The cleavage at 40 C for two hours gave argininevasopressin quantitatively (77% yield)

Yusuf A. Organic Chemistry 2 (SCH 202). Nairobi: University of Nairobi Press; 2004.scan0023.pdf
YUSUF DROKEYOAMIR. "Solid-phase peptide syntheses of oxytocin, oxytocin analogs and interferon short chain with the amide side-chain functionality of asparagine protected with 1-tetralinyl group.". In: Doctor of Philosophy in Chemistry. Journal of the Kenya Chemical Society; 1998. Abstract
1-Tetralone was converted to 1-aminotetralin. This amine was then used to protect the carboxamide side-chain of asparagine. Syntheses of oxytocin and its derivatives were then done via Boc-solid-phase peptide synthesis using this protected asparagine. After syntheses of the nonapeptide resins, cleavage and eventual cyclization of the hormones was done using trifluoromethane sulphonic acid at 40 degrees Celcius for two hours.
Yusuf A, Gitu P, Bhatt BM, Njogu M, Salim A, Orata D. "Solid-Phase Peptide Synthesis of Arginine-vasopressin With Amide Side chain of Asparagine Protected With 1-Tetralinyl Group." Journal of Chemistry & Materials Research. 2014;6(4):60-65.
Yusuf A, Gitu P, Bhatt B, Njogu M, Salim A, Orata D. "1-Tetralinyl as carboxamide protecting group for asparagines and application to N-alpha-t-butyloxycarbonyl (Boc) solid-phase peptide synthesis of oxytocin." chemistry and materials research. 2014;6(2):1-11.
YUSUF DROKEYOAMIR. "Synthesis of 1-aminotetralin and its derivatives by reductive amination of their corresponding 1-tetralones.". In: Int. J. of BioChemiPhysics. Journal of BiochemiPhysics; 1993. Abstract
Tetralones were converted to their corresponding N-formyl derivatives using ammonia and formic acid at 170-180 degrees Celsius. These were then hydrolyzed to the corresponding amines using acid and base. In all cases base hydrolysis gave better yields as compared to acid hydrolysis.

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