Phytochemical Analysis, Baterial And Antifungal Activity Of Compounds Of Alstonia Boonei Stem Bark

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The aim of this study was to investigate the bioactive compounds present in the stem bark of Alstoniaboonei. The plant was selected on the basis of its wide spread use in traditional herbal medicine for the treatment of various ailments like malaria, urinary tract infections, fever, sleeplessness, chronic diarrhea, rheumatic aches and typhoid. The stem bark of Alstoniabooneiplant was collected from Mabira Forest, with the help of a plant taxonomist from the Department of Botany Makerere University. A voucher specimen was deposited at the Herbarium, Department of Botany, Makerere University, for future reference. The collected plant was air-dried under shade, ground into powder and extracted using Dichloromethane:Methanol (1:1) for 24 hours, with occasional stirring, at room temperature. The resulting extract was filtered using cotton wool, followed by Whatman (number 1) filter paper and then dried on a rotatory evaporator to obtain a crude extractThe crude extract was subjected to various chromatographic separations, isolation and purification to yield three pure compounds. Structure elucidation of the isolated pure compounds was achieved by a combination of spectroscopic techniques including 1H NMR, 13C NMR, HMBC, HSQC and COSY. This was done in Germany and the compounds were identified as triterpeneslupeol(1) (3β)-Lup-20(29)-en-3-ol, di-butyl phthalate (2) butyl phthalic acid and β-amyrin ((3beta)-olean-12-en-3-ol) (3). The crude extract and the isolated pure compounds were tested for their antimicrobial properties against Candida albicans,Aspergillusfumigatus, Staphylococcus aureus, Escherichia coli, Enterobacteraerogenes, Pseudomonas aeruginosa and Salmonella enterica. Compounds 1, 2, 3 showed moderate mean zones of inhibition of (8.4±1.2) mm, (5.0±2.5) mmand (8.3±1.4) mm respectively. The crude extract showed very high zones of inhibition of (9.4±0.7) mm. Furthermore, compounds 1and 3 showed high zones of inhibition against Candida Albicans and Arspegillusfumigatus of 12.6±0.2 mm and 12.3±0.7 mm respectively; compound 2 showed moderate mean zone of inhibition of (9±0.4) mm while the crude extract showed the highestzones of inhibition of 13.1±0.2 mm which proves the use of Alstoniaboonei stem bark in treatment of both bacterial and fungal infections.