Now showing items 1-20 of 85

  • Progress in the chemistry of marketed traditionally used plants of Ethiopia 

    Abegaz, B.M. (Chemical Society of Ethiopia., 1996)
  • Phenolic and antibacterial constituents of Vahlia capensis 

    Majinda, Runner R.T.; Motswaledi, Modisa; Waigh, Roger D.; Waterman, Peter G. (Georg Thieme Verlag,, 1997)
    The n-butanol fraction of Vahlia capensis yielded kaempferol, quercetin, afzelin, astragalin, quercitrin, iso-quercitrin, rutin, gallic acid, chiro-inositol, dulcitol, and a novel biflavonoid, VC-15B (vahlia biflavone). ...
  • Bufadienolides and other constituents of Urginea sanguinea 

    Majinda, Runner R.T.; Waigh, Roger D.; Waterman, Peter G. (Georg Thieme Verlag,, 1997)
    Fresh bulbs of Urginea sanguinea yielded stigmasterol, phloroglucinol, phloroglucinol 1-β-D-glucopyranoside (phlorin), scillaren A, a novel compound 5α-4,5-dihydroscillaren A (1), salicylic acid, and 3-hydroxy-4-methylbenzoic ...
  • Quality and Compositional Studies of Some Edible Leguminosae Seed Oils in Botswana 

    Ketshajwang, K.K.; Holmback, J.; Yeboah, S.O. (AOCS Press., 1998)
    Seed oils were extracted with n-hexane from three edible Leguminosae seeds: Tylosema esculentum, Xanthocercis zambesiaca, and Bauhinia petersiana, giving yields of 48.2, 17.6, and 20.8% (w/w), respectively. Some physical ...
  • General Properties and the Fatty Acid Composition of the Oil from the Mophane Caterpillar, Imbrasia belina 

    Motshegwe, S.M.; Holmback, J.; Yeboah, S.O. (AOCS Press., 1998)
    A preliminary investigation of the bulk properties of the oil from the edible mophane caterpillar (phane), Imbrasia belina, showed a significant difference in the iodine values of the oils from mature and young phane. ...
  • Antibiotic activity of selected Botswana Medicinal Plants 

    Majinda, Runner R.T.; Motswaledi, Modisa S. (The Botswana Society,, 1998)
    A number of plant extracts from selected Botswana Medicinal Plants were tested against a battery of organisms for antibiotic activity. The antibiotic profile for most of these extracts seems to support their traditional ...
  • Novel natural products from marketed plants of eastern and southern Africa 

    Abegaz, B.M.; Ngadjui, B.T.; Bezabih, M.; Mdee, L.K. (International Union of Pure and Applied Chemistry., 1999)
    Marketed plants are an important but a vulnerable group of plants whose investigations as well as conservation should be considered with priority. The chemistry, and in some cases biological activities of novel iso¯avonoids, ...
  • Electrospray Liquid Chromatography–Mass Spectrometry of the Leaf Extract of Rhamnus prinoides 

    Nindi, M.M.; Kgarebe, B.V.; Wolfender, J.L.; Abegaz, B.M. (John Wiley & Sons, Ltd., 1999)
    Three naphthalenic derivatives, four flavonoids and two of the four anthraquinones previously isolated from the leaves of Rhamnus prinoides were successfully ionised under electrospray ionisation conditions. These compounds ...
  • The phase separation behaviour and the viscoelastic properties of particles with non-adsorbing polymers: Part I - Experimental study 

    Goodwin, J.W.; Hughes, R.W.; Kwaambwa, H.M.; Reynolds, P.A. (Elseview Science B.V., 2000)
    A series of well characterised cis-polyisoprene polymers have been added to dispersions of PHS coated PMMA particles in dodecane. At a molecular weight of 8000 g mol−1 and above, these systems showed phase separation at ...
  • A bichalcone from the twigs of Rhus pyroides 

    Masesane, I.B.; Yeboah, S.O.; Liebscher, J.; Mugge, C.; Abegaz, B.M. (Elsevier Science Ltd,, 2000)
    The twigs of Rhus pyroides yielded a novel bichalcone 2',40,21-trihydroxy-4',41-dimethoxy-4-O-51-bichalcone. It was identified on the basis of spectroscopic data including 1D and 2D NMR spectroscopy. The name rhuschalcone-1 ...
  • Recent results from natural product research at the University of Botswana 

    Majinda, R.R.T; Abegaz, B.M.; Bezabih, M.; Ngadjui, B.T; Wanjala, C.C.W.; Mdee, L.K.; Bojase, G.; Silayo, A.; Masesane, I.; Yeboah, S.O. (IUPAC., 2001)
    Marketed plants are very important items of trade in many parts of the world. The community uses these for a variety of purposes such as foods, cosmetics, flavors, spices, and medicines. It seems that plants that are ...
  • Gaboroquinones A and B and 4'-O-demethylknipholone-4'-O-β-D-glucopyranoside, phenylanthraquinones from the roots of Bulbine frutescens 

    Abegaz, B.M.; Bezabih, M.; Msuta, T.; Brun, R.; Menche, D.; Muhlbacher, J.; Bringmann, G. (American Chemical Society., 2002)
    The novel phenylanthraquinones 4'-O-demethylknipholone-4'-O-β-D-glucopyranoside (2) and gaboroquinones A (3) and B (4) were isolated from the African medicinal plant Bulbine frutescens. Biaryl 2 represents the first ...
  • Diterpenoids from the stem bark of Croton zambesicus 

    Ngadjui, B.T.; Abegaz, B.M.; Keumedjio, F.; Folefoc, G.N.; Kapchec, G.W.F. (Elsevier Science Ltd., 2002)
    Three clerodane diterpenoids, crotozambefurans A, B and C were isolated from the stem bark of Croton zambesicus together with the known clerodane crotocorylifuran and two trachylobanes: 7b-acetoxytrachyloban-18-oic acid ...
  • Homoisoflavonoids and xanthones from the tubers of wild and in vitro regenerated Ledebouria graminifolia and cytotoxic activities of some of the homoisoflavonoids 

    Mutanyatta, J.; Matapa, B.; Shushu, D.; Abegaz, B. (Elsevier Ltd., 2002)
    Eleven homoisoflavonoids and two xanthones were isolated and characterized from the bulbs of Ledebouria graminifolia. Five of the homoisoflavonoids are new compounds and were identified as: 5-hydroxy-7-methoxy-3-(40-hyd ...
  • Dinklagins A, B and C: three prenylated flavonoids and other constituents from the twigs of Dorstenia dinklagei 

    Ngadjui, B.; Dongo, E.; Abegaz, B.; Fotso, S.; Tamboue, H. (Elsevier Science Ltd., 2002)
    Three prenylated flavonoids, dinklagins A, B and C identified, respectively, as ( )-6-(3,3-dimethylallyl)-7-hydroxy-6000, 6000-dimethylchromeno-( 40,30,2000,3000)-flavanone, (+)-5,40,500x-trihydroxy-600,600-dimethylchro ...
  • The Free-Radical Copolymerization of Difurylmethane with Maleic anhydride 

    Ddamba, W.A.A.; Ngila, J.C.; Mokoena, T.T.; Motlhagodi, K. (South African Journal of Chemistry. <>., 2002)
    The copolymerization of difurylmethane with maleic anhydride in the presence of azobisisobutyronitrile as an initiator has been investigated at 65 °C, 72 °C and 85 °C in different solvents. Reaction feeds containing 85 ...
  • Chalcones and other constituents of Dorstenia prorepens and Dorstenia zenkeri 

    Abegaz, B.M.; Ngadjui, B.T.; Dongo, E.; Ngameni, B.; Nindi, M.N.; Bezabih, M. (Elsevier Science Ltd., 2002)
    The twigs of Dorstenia prorepens furnished the digeranylated chalcone, 5,30-(3,7-dimethyl-2,6-octadienyl)-3,4, 20,40-tetrahydroxychalcone while Dorstenia zenkeri yielded the 30,40-(3-hydroxy-2,2-dimethyldihydropyrano)-4 ...
  • Antimicrobial Flavonoids from Bolusanthus speciosus 

    Bojase, Gomotsang; Majinda, Runner R.T.; Gashe, Berhanu A.; Wanjala, Cornelius C.W. (Georg Thieme Verlag,, 2002)
    A new isoflavanone namely 3,5,7,2′,4′-pentahydroxy-8,3′-di(γ,γ-dimethylallyl)isoflavanone (bolusanthin II) and four new pterocarpans identified as 3-hydroxy-6′,6′-dimethylpyrano[2′,3′:1,2] [6aR,11aR]-8,9-methylenedioxypterocarpan ...
  • Erythrinaline Alkaloids and Antimicrobial Flavonoids from Erythrina latissima 

    Wanjala, Cornelius C.W.; Juma, Benard F.; Bojase, Gomotsang; Gashe, Berhanu A.; Majinda, Runner R.T. (Georg Thieme Verlag,, 2002)
    The seed pods of Erythrina latissima yielded erysotrine, erysodine, syringaresinol, vanillic acid, a new erythrina alkaloid, (+)-10,11-dioxoerysotrine, which was lethal to brine shrimp and 2-(5′-hydroxy-3′-methoxy ...
  • Influence of weak and strong donor groups on the fluorescence parameters and the intersystem crossing rate constant 

    Nijegorodov, N.; Mabbs, R.; Winkoun, D.P. (Elsevier Science Ltd., 2003)
    Please refer to the attached article for an ABSTRACT. The abstract was not uploaded here due to formula appearance problem in UBRISA.