Phytochemical and biological investigation of daniellia oliveri leaves (Fabaceae)
Daniellia oliveri (Rolfe).Hutch and Dalz. (Fabaceae),commonly known as Ilorin balsam or Copaihu Africaine is an indigenous African tree found extensively in Nigeria,Benin,Cameroon and Gambia.The leaves of this plant are being used traditionally in Nigeria to treat bacterial infections,gastrointestinal disturbance, as diuretic and aphrodisiac. The aqueous ethanolic extract was suspended in water and successfully extracted with dichloromethane and n-butanol to give dichloromethane and n-butanol soluble extracts which were investigated for antibacterial activity. The n-butanol extract was found to be active against the test pathogens: S.aureus,B.subtilis,E.coli,P.aeruginosa and S.typhi, with zones of inhibition ranging from 16–27mm using agar well diffusion assay method.The n-butanol extract also inhibited spasmogenes induced contractions of isolated guinea pig ileum and the rhythmic contractions of rabbit jejunum.The anti-diarrheal activity of the extract was also investigated using castor oil induced diarrhea in mice at doses of 50,100 and 200mg/kg. The extract showed significant protection against mice-pretreated with castor oil in comparison with loperamide the standard drug used. Toxicity study of the extract intraperitoneally revealed that the extract was relatively safe.Fractionation of this extract over column chromatography, sephadex LH-20 and preparative tlc led to the isolation of five Flavonoid glycosides identified as isorhamnetin 3-O-rutinoside,quercetin 3-O-rutinoside,quercetin 3-O-glucoside, quercetrin and quercemeritin the structures were elucidated by NMR spectroscopy and compared with literature.Biological studies of the isolated Flavonoids is in progress..