Phytochemical investigationon of the leaves of Millettia ferruginea ssp. darasana fabaceae family and evaluation for antibacterial activities

Abstract

Bacterial infectious diseases are highly widespreadand contribute to the global disease burden and kill many millions of people in developing countries including Ethiopia. The major problem of this health care is due to drug resistance. Therefore, in this study, phytochemical investigation and antibacterial evaluation of the leaf of Millettia ferrugeniasub species darassanawas carried out. Accordingly, the leaf of Millettia ferrugeniassp. darasanawas exhaustively extracted with methanol/chloroform (1:1, v/v) by maceration at room temperature. The obtained crude extract was evaluated for their antibacterial activities against four bacterial strains (Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa and Escherichia coli).The crude extract had shown inhibition zone (11-12.5 mm) on selected bacterial strains. The obtained result has better on Enterococcus faecalis than other bacteria species compared to positive control (gentamycin). Based on these antibacterial activities, the resulting crude extract was subjected to chromatographic separation to afford three compounds (1a-3a). The identity of the isolated compounds were established as 2’’, 2’’-dimethylchromene,3’,4’-methylenedioxy isoflavone (Calopogonium isoflavone B), 2’’, 2’’-dimethylchromene, 5’-methoxy, 3’,4’-methylenedioxy isoflavone and 7,2’-dimethoxy-4’,5’-methylenedioxy isoflavone, based on their, 1D ( 1 H, 13 C) and 2D, (COSY, HSQC and HMBC) NMR data. All identified compounds were evaluated for antibacterial activity against four bacteria strains. Of these, compound 3ahas demonstrated to have better activity on the Pseudomonas aeruginosa bacteria which shows 16 mm inhibition zone compared to gentamycin. Thus, comparing to the standard gentamycin, the crude extract and isolated compounds showed lower zone of inhibition