PHYTOCHEMICAL INVESTIGATION AND EVALUATION OF ANTIMICROBIAL ACTIVITIES OF LEAVES EXTRACTS OF Brucea antidysenterica

Abstract

Brucea antidysenterica is used for traditional medicine in the treatment of various diseases. Specifically the leaf part of the plant was known in the history of folklore medicine in different parts of Ethiopia. The present study was intended to evaluate phytochemicals as well as antimicrobial activities of leaves extracts of Brucea antidysenterica. The powdered leaves of the plant were successively extracted with petroleum ether, chloroform/methanol (1:1) and methanol respectively. The petroleum ether, chloroform/methanol (1:1) and methanol extracts were subjected to phytochemical screening and the results of the screening revealed the presence of a diverse phytochemicals in reference to the solvents. One pure compound coded as BA-1 was isolated from the petroleum ether extract using column chromatography and the structure of this compound was characterized by IR, UV-Vis and 1D NMR ( 1H-NMR, 13CNMR and DEPT-135). The leaves oil was extracted with n-hexane from the leaves of the plant by using Soxhlet apparatus and its chemical compositions were characterized by GC-MS. The GC-MS analysis of n-hexane extract led to the identification of 30 compounds from Brucea antidysenterica representing 100% of the extracted oil. Among them, hexadecanoic acid, methyl ester (18.34 %), hydroxy [(1-oxo-2-propenyl) amino-] acetic acid (8.88 %), α-pinene (8.82 %), 2-ethoxyamphetamine (8.46 %), 1-methyl-2-phenoxyethylamine (7.76 %), methyl tetradecanoate (6.38 %) and 4-methylene-1-(1-methylethyl) bicyclo [3.1.0] hex-2-ene (6.31 %) were the prevailing compounds. Antimicrobial activities of crude extracts, pure compound, fractions and leaves oil were performed against four bacterial and two fungal species. All the tested samples were active against all bacterial species at a dose of 20 µL. BA-1 and fraction were in active at 10 µL against all bacterial species and A.niger. The crude extracts were also subjected to test their antitubercular activity and the results showed that the MeOH extract was very active at minimum concentration (3.12 MIC (µg/mL)) against M.tuberculosis.