Onyancha, Evans M.2011-05-092011-05-092011-05-09http://hdl.handle.net/123456789/388Historically, plants have provided a good source of antimicrobial agents. Plant based antimicrobials represent a vast untapped source of medicine with an enormous therapeutic potential. They are effective in treatment of diseases while simultaneously mitigating many of the side effects that are often associated wills synthetic antimicrobials. The isolated bioactive compounds can be used in future His an antimicrobial or as blueprint or starting point for the manufacture of antimicrobial. The present research concentrated on the Kenyan plant, Teclea nohilis Del. Collected from Siroch in Kerio Valley basin. The powdered dry leaves of Teclea nohilis were successively extracted in hexane, dichloromethane, ethyl acetate and methanol. The resulting crude extracts were tested for lethality test 6y use of brine shrimp (Anemia salina) as well as antimicrobial test. The Hexane crude extract had 235, DCM 165, EtClAc 557 and McOH 268 ug/ml LD50 values. The hexane and dichloromethane crude extracts, showed mild activity for both lethality test and antimicrobial test (9 mm for Staphylococcus aureus and 8 mm for Streptococcus pnuemoniae). The hexane and dichloromethane extracts were subjected to fractionation where seven compounds were isolated and purified by use of chromatographic techniques; vacuum liquid chromatgraphy (VLC), column chromatography (CC) and thin layer chromatography (TLC) that were extensively used. The isolated compounds were kokusaginine (1), 4,8-dimethoxy-7-(3-methylbut-2enyloxy)furo[2,3-b]quinoliue (1I), skimmianine (III), dictaniine (IV), b-sitosterol (V), lupeol (VI), and flindersiamine (VII). The compounds showed antibacterial activity ranging from mild to moderate activity (from 7-11 mm). These activities are relatively high mainly to gram positive bacteria as compared to the activity exhibited by the crude hexane and diclimnetliane extracts. Though the trend exhibited in the crude extracts is maintained by the isolated compounds-gram negative being more susceptible to the extracts. The compounds isolated can be used as templates for the formulation of antibacterial drugs in future given the current trend in drug resistance.enThesis