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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., 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., 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 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., 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., 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., 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., 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., 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 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., 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 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., 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., 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, 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., 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., 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-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 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., 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 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 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 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 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. "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. "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, 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. "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, 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. "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. "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. "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, 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. "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. "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, 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, 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, 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, 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. "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, 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, 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. "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, 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, Twinomuhwezi H, Kabaru JM, Akala HM, Kiremire BT, Heydenreich M, Peter. "Antiplasmodial and larvicidal flavonoids from Derris trifoliata.". 2009.Website
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. "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. "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. "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. "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 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. "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, 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, 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. "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. "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, 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, 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. "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, 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. "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. "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, 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. "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. "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. "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. "Phtytochemical evaluation of Kenyan medicinal plants. .". In: The 11th NAPRECA Symposium. Antananarivo, Madagascar; 2005.midiwo_et_al-11th_napreca_proceedings.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, 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. "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.

Yebouet M-FA, Diby AK, Kaduki KA, Zoueu JT. "Unstained blood smear contrast enhancement using spectral time multiplexing super resolution." Journal of Spectral Imaging. 2020;9. 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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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 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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Yaşargil MG. Clinical {Considerations}, {Surgery} of the {Intracranial} {Aneurysms} and {Results}. Thieme; 1984. Abstract

Clinical Considerations, Surgery of the Intracranial Aneurysma and Results

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

Clinical Considerations, Surgery of the Intracranial Aneurysma and Results

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.

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
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.

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

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.
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Yang X, Özdemir ŞK, Peng B, Yilmaz H, Lei F-C, Long G-L, Yang L. "Raman gain induced mode evolution and on-demand coupling control in whispering-gallery-mode microcavities." Optics Express. 2015;23:29573-29583. Abstract
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Yang X, He Z, Zheng Y, Wang N, Mulinge M, Schmit J-C, Steinmetz A, Seguin-Devaux C. "Chemical Constituents of and Their Anti-HIV-1 Activity." Molecules. 2021;26(9). Abstract

Three new (-) and 25 known compounds were isolated from the crude extract of . The chemical structures of new compounds were established by extensive spectroscopic analyses including 1D and 2D NMR and HRESIMS. Cassiabrevone () is the first heterodimer of guibourtinidol and planchol A. Compound was a new chalcane, while was a new naphthalene. Cassiabrevone (), guibourtinidol-(4α→8)-epiafzelechin (), taxifolin (), oleanolic acid (), piceatannol (), and palmitic acid (), exhibited potent anti-HIV-1 activity with IC values of 11.89 µM, 15.39 µM, 49.04 µM, 7.95 µM, 3.58 µM, and 15.97 µM, respectively.

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.

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).

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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.  

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

Y E. "Environmental considerations shaping the hospital building and governing its space.". In: AMEK 3rd Scientific Conference & Exhibition,. NHIF Building, Nairobi.; 2005.
Y E. " Sustainable Materials and Construction Technology.". In: AAK Mombasa Chapter: Seminar. Royal Court Hotel, Mombasa; 2006.
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Xujing. Comparative Study of China-US MBA Education . : Northeast Normal University ; 2008.
XuEmail Y, Seward P, Gaye C, Lin L, Olago DO. "Preface: Groundwater in Sub-Saharan Africa." Hydrogeology Journal. 2019;27(3):815-822. Abstractxu2019_article_prefacegroundwaterinsub-sahara1.pdfWebsite

Introduction
Sub-Saharan Africa (SSA; Fig. 1) refers to an area encompassing the countries in Africa that are fully, or partially, located south of the Sahara. The remaining African countries are generally referred to as belonging in North Africa. Although the socio-economic and hydrogeological conditions in SSA are diverse, they are sufficiently distinct (in general) from the conditions in North Africa to warrant being assessed separately—for example, high-yielding, high-storage, sedimentary aquifers are more common in North Africa than in SSA, while low-yielding, low-storage, basement aquifers are more widespread in SSA than in North Africa. The use of fossil groundwater is more typical in North Africa, while the use or renewable groundwater is more typical in SSA. Other hydrological characteristics associated with SSA include: groundwater resources that are generally under-utilized; lack of research and development that often prevents the optimal use of groundwater rather than over-development; and a heavy reliance by the rural and urban poor on shallow unconfined or semi-confined groundwater for potable water supplies, other domestic uses, and subsistence agriculture. Because of distinguishing characteristics such as these, there are good reasons for treating the hydrogeology of SSA as a whole, and separate from North Africa.

Xu Y, Ning Z, Zhang H, Ni G, Shao H, Peng B, Zhang X, He X, Zhu Y, Zhu H. "The anisotropic ultrahigh hole mobility in strain-engineering two-dimensional penta-SiC $ \_2$." arXiv preprint arXiv:1701.03715. 2017. Abstract
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Xu Y, Seward P, Gaye C, Lin L, Olago DO. "Groundwater in Sub-Saharan Africa." Hydrogeology Journal. 2019;27(3):815-822. AbstractWebsite

Sub-Saharan Africa (SSA; Fig. 1) refers to an area encompassing the countries in Africa that are fully, or partially, located south of the Sahara. The remaining African countries are generally referred to as belonging in North Africa. Although the socio-economic and hydrogeological conditions in SSA are diverse, they are sufficiently distinct (in general) from the conditions in North Africa to warrant being assessed separately—for example, high-yielding, high-storage, sedimentary aquifers are more common in North Africa than in SSA, while low-yielding, low-storage, basement aquifers are more widespread in SSA than in North Africa. The use of fossil groundwater is more typical in North Africa, while the use or renewable groundwater is more typical in SSA. Other hydrological characteristics associated with SSA include: groundwater resources that are generally under-utilized; lack of research and development that often prevents the optimal use of groundwater rather than over-development; and a heavy reliance by the rural and urban poor on shallow unconfined or semi-confined groundwater for potable water supplies, other domestic uses, and subsistence agriculture. Because of distinguishing characteristics such as these, there are good reasons for treating the hydrogeology of SSA as a whole, and separate from North Africa.

Xu S, Waiganjo P, Dias PG, Shi B. "Testability Prediction for Sequential Circuits Using Neural Network.". In: Proceedings of the 6th Asian Test Symposium. Washington, DC, USA: IEEE Computer Society; 1997:. ATS '97. Abstract
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Xu Y, Zhang H, Shao H, Ni G, Li J, Lu H, Zhang R, Peng B, Zhu Y, Zhu H, others. "First-principles study on the electronic, optical, and transport properties of monolayer $\alpha$-and $\beta$-GeSe." Physical Review B. 2017;96:245421. Abstract
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Xu X, Du Q, Peng B, Xiong Q, Hong L, Demir HV, Wong TKS, Kyaw AKK, Sun X. "Effect of shell thickness on small-molecule solar cells enhanced by dual plasmonic gold-silica nanorods." Applied Physics Letters. 2014;105:148\_1. Abstract
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Xu X, Kyaw AKK, Peng B, Zhao D, Wong TKS, Xiong Q, Sun X, Heeger AJ. "A plasmonically enhanced polymer solar cell with gold–silica core–shell nanorods." Organic electronics. 2013;14:2360-2368. Abstract
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Xu Y, Ning Z, Zhang H, Ni G, Shao H, Peng B, Zhang X, He X, Zhu Y, Zhu H. "Anisotropic ultrahigh hole mobility in two-dimensional penta-SiC 2 by strain-engineering: electronic structure and chemical bonding analysis." RSC advances. 2017;7:45705-45713. Abstract
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Xu Y, Zhang H, Shao H, Ni G, Lu H, Zhang R, Peng B, Zhu Y, Zhu H. "Electronic, transport and optical properties of monolayer $$\backslash$alpha $ and $$\backslash$beta-$ GeSe: A first-principles study." arXiv preprint arXiv:1704.03336. 2017. Abstract
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Xu K, Xu Y, Zhang H, Peng B, Shao H, Ni G, Li J, Yao M, Lu H, Zhu H, others. "Electronic, optical and transport properties of van der Waals Transition-metal Dichalcogenides Heterostructures: A First-principle Study." arXiv preprint arXiv:1804.02518. 2018. Abstract
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Xu X, Kyaw AKK, Peng B, Xiong Q, Demir HV, Wang Y, Wong TKS, Sun X. "Influence of gold-silica nanoparticles on the performance of small-molecule bulk heterojunction solar cells." Organic Electronics. 2015;22:20-28. Abstract
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Xu X, Kyaw AKK, Peng B, Du Q, Hong L, Demir HV, Wong TKS, Xiong Q, Sun X. "Enhanced efficiency of solution-processed small-molecule solar cells upon incorporation of gold nanospheres and nanorods into organic layers." Chemical Communications. 2014;50:4451-4454. Abstract
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Xu K, Xu Y, Zhang H, Peng B, Shao H, Ni G, Li J, Yao M, Lu H, Zhu H, others. "The role of Anderson’s rule in determining electronic, optical and transport properties of transition metal dichalcogenide heterostructures." Physical Chemistry Chemical Physics. 2018;20:30351-30364. Abstract
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Xie Y, Peng B, Bravić I, Yu Y, Dong Y, Liang R, Ou Q, Monserrat B, Zhang S. "Highly efficient blue-emitting CsPbBr3 perovskite nanocrystals through neodymium doping." Advanced Science. 2020;7:2001698. Abstract
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Xie Y, Peng B, Bravić I, Yu Y, Dong Y, Liang R, Ou Q, Monserrat B, Zhang S. "Perovskite Nanocrystals: Highly Efficient Blue-Emitting CsPbBr3 Perovskite Nanocrystals through Neodymium Doping (Adv. Sci. 20/2020)." Advanced Science. 2020;7:2070112. Abstract
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Xia Y-J, Lin J, Tang C, Yin K, Zhong G-Y, Ni G, Peng B, Gan F-X, Huang W. "High-efficiency blue-emitting organic light-emitting devices with 4, 4′, 4 ″-tris (N-carbazolyl)-triphenylamine as the hole/exciton-blocking layer." Journal of Physics D: Applied Physics. 2006;39:4987. Abstract
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Wycliffe O, Richard O, Hillary N, Wangia S, Chimoita E. "Farmers knowledge, attitude, and perception of video-mediated learning vis-a-vis Farmers Field School on Striga weed management in Western Kenya." International Journal of Education and Development using Information and Communication Technology (IJEDICT). 2018;14(2)(ISSN):195-210.
Wyckliff N, Kitaa J, Thaiyah A, Maingi N, Muriuki JB, others. "Coprological Study to Determine the Prevalence of Intestinal Helminthes in Dogs of Nairobi, Kenya-A Potential Zoonotic Threat." Int J Vet Sci Res. 2017;3:025-029. Abstract
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Wyckliff N, Kitaa J, Thaiyah A, others. "Community's perception on zoonotic potential of dog helminthes infections in Kangemi slum of Nairobi, Kenya." International Journal of Veterinary Science. 2017;6:90-95. Abstract
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Wurzinger M;, Ndumu D;, Baumung R;, Drucker AG;, Okeyo AM;, Semambo DK;, Sölkner J. "TitleAssessing stated preferences through the use of choice experiments: valuing (re)production versus aesthetics in the breeding goals of Ugandan Ankole cattle breeders.".; 2006. Abstract

Home Help Thesaurus Okeyo AM Advanced Search Tools Marked records Mark this record Search History Print this record Email this record Export citation Download MARC21 Record Related literature •Other articles by these authors on Google Scholar •Search Google for related articles • Order from the British Library (Artweb-registered users) •Order from the British Library (public order form) •Find this book on Amazon •Search for this title in NRC-CISTI •Add to … Tag in Delic.io.us Tag in Connotea Document details TitleAssessing stated preferences through the use of choice experiments: valuing (re)production versus aesthetics in the breeding goals of Ugandan Ankole cattle breeders. AuthorsWurzinger, M.; Ndumu, D.; Baumung, R.; Drucker, A. G.; Okeyo, A. M.; Semambo, D. K.; Sölkner, J. Book chapter; Conference paperProceedings of the 8th World Congress on Genetics Applied to Livestock Production, Belo Horizonte, Minas Gerais, Brazil, 13-18 August, 2006 2006 pp. 31-09 Conference TitleProceedings of the 8th World Congress on Genetics Applied to Livestock Production, Belo Horizonte, Minas Gerais, Brazil, 13-18 August, 2006. ISBN85-60088-01-6 URLhttp://www.wcgalp8.org.brRecord Number20063170234 Abstract In this study 240 cattle keepers in four regions in Southwestern Uganda were interviewed and a hypothetical choice experiment was conducted. Each choice-set consisted of 2 profiles with 6 attributes with 2 levels. The attributes for cows were horns, coat colour, size, fertility, milk yield and price. The attributes for bulls were horns, colour, muscularity, temperament, dam's performance and price. Each person got 6 choice-sets for bulls and 6 for cows. Differences in the production systems were reflected in the varying selection criteria. In cows production traits were very important and in bull

Wurzinger M;, Ndumu D;, Baumung R;, Drucker A;, Okeyo AM;, Semambo DK;, Sölkner J. "Indigenous selection criteria in Ankole cattle and different production systems in Uganda."; 2005. Abstract

Ankole cattle are kept in South-Western Uganda, which is part of the cattle corridor, an area that was traditionally communal grazing land and pastoral systems. Currently, the pastoral system is undergoing a dramatic change due to land shortage, market forces and political reasons. Four different regions were identified and 30 farmers each were interviewed. In the two areas with more traditional systems main selection criteria in cows and bulls are body characteristics (coat colour, horn size and colour). Here, herds are generally larger and cattle are the main source of income. During the dry season, some families still move with their cattle in search of water and pasture. In the two other areas farmers are sedentary and both livestock and crop production contribute to the income. Due to increasing population pressure the trend is to keep few but more productive animals. Selection focuses more on production traits like milk yield, growth and fertility. Crossbreeding with exotic cattle breeds is becoming more popular. Farmers mention that Ankole have advantages over exotic breeds in terms of disease resistance, heat tolerance, lower feed requirements and the beauty of the animals. The study reported here was carried out to describe the production system with a focus on indigenous knowledge and the documentation of changes. Implications of the on-going changes on future development and improvement interventions are also discussed.

Wurzinger M, Okeyo AM, Semambo D, Solkner J. "The sedentarisation process of the Bahima in Uganda: An emic view.". 2009. Abstract

The traditional lifestyle of nomadic pastoralists is vanishing rapidly, because of human population growth which often leads to land scarcity or political pressure on pastoralists to settle. The sedentarisation of the Bahima pastoralists in Western Uganda started in the 1940s and is still going on. In this study former nomadic cattle keepers, who have settled with their families, were interviewed in order to document the decision to settle and the subsequent changes in the lifestyle of these people. All interviewees expressed their satisfaction with their sedentary life. Land scarcity, access to education, better availability of water and the possibility of crop production were given as factors for settlement. The decisions were influenced by Christian missionaries, the government and friends.

Wu C, Zhang G, Xia T, Li Z, Zhao K, Deng Z, Guo D, Peng B. "Bioinspired synthesis of polydopamine/Ag nanocomposite particles with antibacterial activities." Materials Science and Engineering: C. 2015;55:155-165. Abstract
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Wu C, Deng Z, Shang B, Ikkala O, Peng B. "A versatile colloidal Janus platform: surface asymmetry control, functionalization, and applications." Chemical Communications. 2018;54:12726-12729. Abstract
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Wu C, Deng Z, Shang B, Ikkala O, Peng B, others. "A versatile colloidal Janus platform.". 2018. Abstract
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Wu Y, Hua J, Zhou Z, Zhang J, Liu S, Peng B, Fang Y, Ning X, Nie Z, Li F, others. "High-throughput injection–acceleration of electron bunches from a linear accelerator to a laser wakefield accelerator." Nature Physics. 2021;17:801-806. Abstract
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WSK Ruto, JI Kinyamario, JI Kanya NKN’etich. "ariation in the Chemical Status of Water and Soil Sediments along Saiwa Swamp Ecosystem, Trans Nzoia County, Kenya." Asian Journal of Water, Environment and Pollution. 2017;14(3):19-26.
Wrightstone RN, Smith LL, Wilson JB, Vella F, Huisman TH. "Some physicochemical properties of hemoglobin-manitoba (alpha2 102Ser replaced by Arg (G9) beta2)." Biochim. Biophys. Acta. 1975;412(2):283-7. Abstract

Hb-Manitoba was discovered in 1970 [1] in a Canadian family of British origin. Recently we observed the same variant in a second family, and found that the oxy-derivative of Hb-Manitoba is slightly unstable at 65 degrees C, dissociates less readily at alkaline pH than does Hb-A, and forms asymmetric hybrids with other hemoglobins which are readily detectable by electrophoresis.

WR M, Collins K. Mweresa, Philemon Omusula, Benedict O. Orindi, Renate C. Smallegange, Joop JA van Loon, Takken W. "Evaluation of low density polyethylene and nylon for delivery of synthetic mosquito attractants." Parasites & Vectors. 2012;5:202.
Woyengo TA;, Gachuiri CK;, Wahome RG;, Mbugua PN. "Economic evaluation of increasing the energy value of Zea mays stover by urea treatment.".; 2004.
Woyengo TA;, Gachuiri CK;, Wahome RG;, Mbugua PN. "Economic evaluation of increasing the energy value of Zea mays stover by urea treatment.".; 2004.
Woyengo TA;, Gachuiri CK;, Wahome RG;, Mbugua PN. "Economic evaluation of increasing the energy value of Zea mays stover by urea treatment.".; 2004.
Wosyanju, M.G., Kindiki, J.N., Kalai JM. "Impact of brain drain on quality of education in Moi University. ." Journal of Emerging Trends in Educational Research and Policy Studies (JETERAPS) . 2012;3(3):241-246.impact_of_brain_drain_on_the_quality_of_education.pdf
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Brizuela V, Bonet M, Romero CLT, Abalos E, Baguiya A, Fawole B, Knight M, Lumbiganon P, Minkauskienė M, Nabhan A, Osman NB, Qureshi ZP, Souza JP. "Early evaluation of the 'STOP SEPSIS!' WHO Global Maternal Sepsis Awareness Campaign implemented for healthcare providers in 46 low, middle and high-income countries." BMJ Open. 2020;10(5):e036338. Abstract

To evaluate changes in awareness of maternal sepsis among healthcare providers resulting from the WHO Global Maternal Sepsis Study (GLOSS) awareness campaign.

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wood, et al. "Transepithelial potential in the Magadi tilapia, a fish living in extreme alkalinity." Journal of Comparative Physiology B. . 2012;182 (2):247-258. AbstractSpringer Link

We investigated the transepithelial potential (TEP) and its responses to changes in the external medium in Alcolapia grahami, a small cichlid fish living in Lake Magadi, Kenya. Magadi water is extremely alkaline (pH = 9.92) and otherwise unusual: titratable alkalinity (290 mequiv L−1, i.e. HCO3 − and CO3 2−) rather than Cl− (112 mmol L−1) represents the major anion matching Na+ = 356 mmol L−1, with very low concentrations of Ca2+ and Mg2+ (<1 mmol L−1). Immediately after fish capture, TEP was +4 mV (inside positive), but stabilized at +7 mV at 10–30 h post-capture when experiments were performed in Magadi water. Transfer to 250% Magadi water increased the TEP to +9.5 mV, and transfer to fresh water and deionized water decreased the TEP to −13 and −28 mV, respectively, effects which were not due to changes in pH or osmolality. The very negative TEP in deionized water was attenuated in a linear fashion by log elevations in [Ca2+]. Extreme cold (1 vs. 28°C) reduced the positive TEP in Magadi water by 60%, suggesting blockade of an electrogenic component, but did not alter the negative TEP in dilute solution. When fish were transferred to 350 mmol L−1 solutions of NaHCO3, NaCl, NaNO3, or choline Cl, only the 350 mmol L−1 NaHCO3 solution sustained the TEP unchanged at +7 mV; in all others, the TEP fell. Furthermore, after transfer to 50, 10, and 2% dilutions of 350 mmol L−1 NaHCO3, the TEPs remained identical to those in comparable dilutions of Magadi water, whereas this did not occur with comparable dilutions of 350 mmol L−1 NaCl—i.e. the fish behaves electrically as if living in an NaHCO3 solution equimolar to Magadi water. We conclude that the TEP is largely a Na+ diffusion potential attenuated by some permeability to anions. In Magadi water, the net electrochemical forces driving Na+ inwards (+9.9 mV) and Cl− outwards (+3.4 mV) are small relative to the strong gradient driving HCO3 − inwards (−82.7 mV). Estimated permeability ratios are P Cl/P Na = 0.51–0.68 and PHCO3/PNa = 0.10–0.33. The low permeability to HCO3 − is unusual, and reflects a unique adaptation to life in extreme alkalinity. Cl− is distributed close to Nernst equilibrium in Magadi water, so there is no need for lower P Cl. The higher P Na likely facilitates Na+ efflux through the paracellular pathway. The positive electrogenic component is probably due to active HCO3 − excretion.

Wood CM, Bergman HL, Bianchini A, Laurent P, Maina J, Johannsson OE, Bianchini LF, Chevalier C, Kavembe GD, Papah MB, Ojoo RO. "Transepithelial potential in the Magadi tilapia, a fish living in extreme alkalinity.". 2012. Abstract

We investigated the transepithelial potential (TEP) and its responses to changes in the external medium in Alcolapia grahami, a small cichlid fish living in Lake Magadi, Kenya. Magadi water is extremely alkaline (pH = 9.92) and otherwise unusual: titratable alkalinity (290 mequiv L(-1), i.e. HCO(3) (-) and CO(3) (2-)) rather than Cl(-) (112 mmol L(-1)) represents the major anion matching Na(+) = 356 mmol L(-1), with very low concentrations of Ca(2+) and Mg(2+) (<1 mmol L(-1)). Immediately after fish capture, TEP was +4 mV (inside positive), but stabilized at +7 mV at 10-30 h post-capture when experiments were performed in Magadi water. Transfer to 250% Magadi water increased the TEP to +9.5 mV, and transfer to fresh water and deionized water decreased the TEP to -13 and -28 mV, respectively, effects which were not due to changes in pH or osmolality. The very negative TEP in deionized water was attenuated in a linear fashion by log elevations in [Ca(2+)]. Extreme cold (1 vs. 28°C) reduced the positive TEP in Magadi water by 60%, suggesting blockade of an electrogenic component, but did not alter the negative TEP in dilute solution. When fish were transferred to 350 mmol L(-1) solutions of NaHCO(3), NaCl, NaNO(3), or choline Cl, only the 350 mmol L(-1) NaHCO(3) solution sustained the TEP unchanged at +7 mV; in all others, the TEP fell. Furthermore, after transfer to 50, 10, and 2% dilutions of 350 mmol L(-1) NaHCO(3), the TEPs remained identical to those in comparable dilutions of Magadi water, whereas this did not occur with comparable dilutions of 350 mmol L(-1) NaCl-i.e. the fish behaves electrically as if living in an NaHCO(3) solution equimolar to Magadi water. We conclude that the TEP is largely a Na(+) diffusion potential attenuated by some permeability to anions. In Magadi water, the net electrochemical forces driving Na(+) inwards (+9.9 mV) and Cl(-) outwards (+3.4 mV) are small relative to the strong gradient driving HCO(3) (-) inwards (-82.7 mV). Estimated permeability ratios are P (Cl)/P (Na) = 0.51-0.68 and [Formula: see text] = 0.10-0.33. The low permeability to HCO(3) (-) is unusual, and reflects a unique adaptation to life in extreme alkalinity. Cl(-) is distributed close to Nernst equilibrium in Magadi water, so there is no need for lower P (Cl). The higher P (Na) likely facilitates Na(+) efflux through the paracellular pathway. The positive electrogenic component is probably due to active HCO(3) (-) excretion.

Wood CM, Wilson P, Bergman HL, Bergman AN, Laurent P, Otiang’a‐Owiti, George; Walsh PJ. "Obligatory urea production and the cost of living in the Magadi tilapia revealed by acclimation to reduced salinity and alkalinity.". 2002. Abstract

Alcolapia grahami is a unique ureotelic tilapia that lives in the highly alkaline, saline Lake Magadi, Kenya (pH, approximately 10.0; alkalinity, approximately 380 mmol L(-1); Na(+), approximately 350 mmol L(-1); Cl(-), approximately 110 mmol L(-1); osmolality, approximately 580 mosm kg(-1)). The fish survived well upon gradual exposure to dilute lake water (down to 1%, essentially freshwater). Urea excretion continued, and there was no ammonia excretion despite favorable conditions, indicating that ureotelism is obligatory. Levels of most ornithine-urea cycle enzymes in the liver were unchanged relative to controls kept for the same period in 100% lake water. The fish exhibited good abilities for hypo- and hyperregulation, maintaining plasma Na(+), Cl(-), and osmolality at levels typical of marine and freshwater teleosts in 100% and 1% lake water, respectively. Plasma total CO(2) did not change with environmental dilution. Routine oxygen consumption (Mo(2)) was extremely high in 100% lake water but decreased by 40%-68% after acclimation to dilute lake water. At every fixed swimming speed, Mo(2) was significantly reduced (by 50% at high speeds), and critical swimming speed was elevated in fish in 10% lake water relative to 100% lake water. Osmotic and Cl(-) concentration gradients from water to plasma were actually increased, and osmotic and Na(+) gradients were reversed, in 10% and 1% dilutions relative to 100% lake water, whereas acid-base gradients were greatly reduced. We suggest that approximately 50% of the animal's high metabolic demand originates from the cost of acid-base regulation in the highly alkaline Lake Magadi. When this load is reduced by environmental dilution, the energy saved can be diverted to enhanced swimming performance.

Wood CM, Bergman HL, Bianchini A, Laurent P, Maina J, Johannsson OE, Bianchini LF, Chevalier C, Kavembe GD, Papah MB, Ojoo RO. "Transepithelial potential in the Magadi tilapia, a fish living.". 2005. Abstract

We investigated the transepithelial potential (TEP) and its responses to changes in the external medium in Alcolapia grahami, a small cichlid fish living in Lake Magadi, Kenya. Magadi water is extremely alkaline (pH = 9.92) and otherwise unusual: titratable alkalinity (290 mequiv L-1, i.e. HCO3 - and CO3 2-) rather than Cl-(112 mmol L-1) represents the major anion matching Na? = 356 mmol L-1, with very low concentrations of Ca2? and Mg2? (\1 mmol L-1). Immediately after fish capture, TEP was ?4 mV (inside positive), but stabilized at ?7 mV at 10–30 h post-capture when experiments were performed in Magadi water. Transfer to 250% Magadi water increased the TEP to ?9.5 mV, and transfer to fresh water and deionized water decreased the TEP to-13 and-28 mV, respectively, effects which were not due to changes in pH or osmolality. The very negative TEP in deionized water was attenuated in a linear fashion by log elevations in [Ca2?]. Extreme cold (1 vs. 28 C) reduced the positive TEP in Magadi water by 60%, suggesting blockade of an electrogenic component, but did not alter the negative TEP in dilute solution. When fish were transferred to 350 mmol L-1 solutions of NaHCO3, NaCl, NaNO3, or choline Cl, only the 350 mmol L-1 NaHCO3 solution sustained the TEP unchanged at ?7 mV; in all others, the TEP fell. Furthermore, after transfer to 50, 10, and 2% dilutions of 350 mmol L-1 NaHCO3, the TEPs remained identical to those in comparable dilutions of Magadi water, whereas this did not occur with comparable dilutions of 350 mmol L-1 NaCl— i.e. the fish behaves electrically as if living in an NaHCO3 solution equimolar to Magadi water. We conclude that the TEP is largely a Na? diffusion potential attenuated by some permeability to anions. In Magadi water, the net electrochemical forces driving Na? inwards (?9.9 mV) and Cl- outwards (?3.4 mV) are small relative to the strong gradient

wood, et al. "Responses to Ammonia Loading in the Magadi Tilapia, a Completely Ureotelic Teleost Fish.". In: Canadian Society of Zoologists meeting. Mount Allison University, Sackville, NB Canada; 2012.
wood, et al. "The Magadi Tilapia- Coping with Extremity. .". In: Tropical fish symposium of the fish biology congress (American fisheries society). Madison Winconsin USA; 2012.
Wood CM, Bergman HL, Bianchini A, Laurent P, Maina J, Johannsson OE, Bianchini LF, Chevalier C, Kavembe GD, Papah MB, Ojoo RO. "Transepithelial potential in the Magadi tilapia, a fish living in extreme alkalinity.". 2012. Abstract

We investigated the transepithelial potential (TEP) and its responses to changes in the external medium in Alcolapia grahami, a small cichlid fish living in Lake Magadi, Kenya. Magadi water is extremely alkaline (pH = 9.92) and otherwise unusual: titratable alkalinity (290 mequiv L(-1), i.e. HCO(3) (-) and CO(3) (2-)) rather than Cl(-) (112 mmol L(-1)) represents the major anion matching Na(+) = 356 mmol L(-1), with very low concentrations of Ca(2+) and Mg(2+) (<1 mmol L(-1)). Immediately after fish capture, TEP was +4 mV (inside positive), but stabilized at +7 mV at 10-30 h post-capture when experiments were performed in Magadi water. Transfer to 250% Magadi water increased the TEP to +9.5 mV, and transfer to fresh water and deionized water decreased the TEP to -13 and -28 mV, respectively, effects which were not due to changes in pH or osmolality. The very negative TEP in deionized water was attenuated in a linear fashion by log elevations in [Ca(2+)]. Extreme cold (1 vs. 28°C) reduced the positive TEP in Magadi water by 60%, suggesting blockade of an electrogenic component, but did not alter the negative TEP in dilute solution. When fish were transferred to 350 mmol L(-1) solutions of NaHCO(3), NaCl, NaNO(3), or choline Cl, only the 350 mmol L(-1) NaHCO(3) solution sustained the TEP unchanged at +7 mV; in all others, the TEP fell. Furthermore, after transfer to 50, 10, and 2% dilutions of 350 mmol L(-1) NaHCO(3), the TEPs remained identical to those in comparable dilutions of Magadi water, whereas this did not occur with comparable dilutions of 350 mmol L(-1) NaCl-i.e. the fish behaves electrically as if living in an NaHCO(3) solution equimolar to Magadi water. We conclude that the TEP is largely a Na(+) diffusion potential attenuated by some permeability to anions. In Magadi water, the net electrochemical forces driving Na(+) inwards (+9.9 mV) and Cl(-) outwards (+3.4 mV) are small relative to the strong gradient driving HCO(3) (-) inwards (-82.7 mV). Estimated permeability ratios are P (Cl)/P (Na) = 0.51-0.68 and [Formula: see text] = 0.10-0.33. The low permeability to HCO(3) (-) is unusual, and reflects a unique adaptation to life in extreme alkalinity. Cl(-) is distributed close to Nernst equilibrium in Magadi water, so there is no need for lower P (Cl). The higher P (Na) likely facilitates Na(+) efflux through the paracellular pathway. The positive electrogenic component is probably due to active HCO(3) (-) excretion.

wood, et al. "Rh Proteins and NH4+ –activated Na+-ATPase in the Magadi Tilapia (Alcolapia grahami), a 100% Ureotelic Teleost Fish." Journal of Experimental Biology. 2013;216:2998-3007 . Abstracthttp://jeb.biologists.org

The small cichlid fish Alcolapia grahami lives in Lake Magadi, Kenya, one of the most extreme aquatic environments on Earth (pH ~10, carbonate alkalinity ~300 mequiv l−1). The Magadi tilapia is the only 100% ureotelic teleost; it normally excretes no ammonia. This is interpreted as an evolutionary adaptation to overcome the near impossibility of sustaining an NH3 diffusion gradient across the gills against the high external pH. In standard ammoniotelic teleosts, branchial ammonia excretion is facilitated by Rh glycoproteins, and cortisol plays a role in upregulating these carriers, together with other components of a transport metabolon, so as to actively excrete ammonia during high environmental ammonia (HEA) exposure. In Magadi tilapia, we show that at least three Rh proteins (Rhag, Rhbg and Rhcg2) are expressed at the mRNA level in various tissues, and are recognized in the gills by specific antibodies. During HEA exposure, plasma ammonia levels and urea excretion rates increase markedly, and mRNA expression for the branchial urea transporter mtUT is elevated. Plasma cortisol increases and branchial mRNAs for Rhbg, Rhcg2 and Na+,K+-ATPase are all upregulated. Enzymatic activity of the latter is activated preferentially by NH4+ (versus K+), suggesting it can function as an NH4+-transporter. Model calculations suggest that active ammonia excretion against the gradient may become possible through a combination of Rh protein and NH4+-activated Na+-ATPase function.

Woo PT. "Cryptobia and cryptobiosis in fishes." Adv. Parasitol.. 1987;26:199-237.
Wong KK, Bulimo WD, Magana J, Achilla RA, Schwarcz SK, Simwa M, Majanja JM, Wadegu MO, Osuna FA, Mukunzi SO, Mwangi JK, Wangui JM, Muthoni JN, Njiri JO, Obura BD, Opot BH, Mitei KK, Barani J, Lifumo S, Schnabel DC. "Epidemiology of 2009 Pandemic Influenza A Virus Subtype H1N1 Among Kenyans Aged 2 Months to 18 Years, 2009–2010." Journal of Infectious Diseases. 2012;206:S68-S73. Abstractj_infect_dis.-2012-wong-s68-73.pdfWebsite

Background.The US Army Medical Research Unit–Kenya (USAMRU-K) conducts surveillance for influenza-like illness (ILI) in Kenya. We describe the temporal and geographic progression of A(H1N1)pdm09 as it emerged in Kenya and characterize the outpatient population with A(H1N1)pdm09 infection.Methods.We included patients with ILI aged 2 months to 18 years enrolled during June 2009–August 2010. Respiratory specimens were tested by real-time reverse-transcription polymerase chain reaction for influenza virus. Patients with A(H1N1)pdm09 infection were compared to those with seasonal influenza A virus infection and those with ILI who had no virus or a virus other than influenza virus identified (hereafter, “noninfluenza ILI”).Results.Of 4251 patients with ILI, 193 had laboratory-confirmed A(H1N1)pdm09 infection. The first pandemic influenza case detected by USAMRU-K surveillance was in August 2009; peak activity nationwide occurred during October–November 2009. Patients with A(H1N1)pdm09 infection were more likely to be school-aged, compared with patients with seasonal influenza A virus infection (prevalence ratio [PR], 2.0; 95% confidence interval [CI], 1.3–3.1) or noninfluenza ILI (PR, 3.2; 95% CI, 2.4–4.3).Conclusions.USAMRU-K ILI surveillance detected the geographic and temporal distribution of pandemic influenza in Kenya. The age distribution of A(H1N1)pdm09 infections included more school-aged children, compared with seasonal influenza A virus infection and noninfluenza ILI.

Wong ROL, Ghosh A. "Activity-dependent regulation of dendritic growth and patterning." Nature Reviews Neuroscience. 2002;3:803-812. AbstractWebsite

One of the most remarkable features of the developing brain is its ability to undergo structural change in response to experience. Among the cellular elements that show this kind of plasticity are dendrites, which are the components that receive and process synaptic information. Recent observations indicate that calcium signalling in neurons can regulate dendritic growth and remodelling by several mechanisms, and these mechanisms are likely to be key mediators of structural plasticity in the developing brain.

Wondimu W, Bogale A, Babege T. "AJPS Articles." Evaluation. 2018.
Wolfsdorf J, Glaser N, Sperling MA, American Diabetes Association. "Diabetic ketoacidosis in infants, children, and adolescents: {A} consensus statement from the {American} {Diabetes} {Association}." Diabetes Care. 2006;29:1150-1159. Abstract
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Wolfgang Richard Mukabana, Janet Achieng Onyango CKM. "Artisanal fishing supports breeding of malaria mosquitoes in Western Kenya." Malaria Journal. 2019;188:77.
Wolfgang R. Mukabana, Collins K. Mweresa, Bruno Otieno, Philemon Omusula, Renate C. Smallegange, Joop JA van Loon, Takken W. "A novel synthetic odorant blend for trapping of malaria and other african mosquito species." Journal of Chemical Ecology. 2012;38:235-244.
With McCormick D, Chitere P, Orero R, Ommeh M. "Paratransit Business Strategies : A Bird’s Eye View of Matatu in Nairobi’ ." Journal of Public Transport. Forthcoming.

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