Evaluation of Antibacterial Activities of Compounds Isolated from Fruits of Sida rhombifolia linn

Abstract

The main objective of this study was to isolate compounds from fruit of Sida rhombifolia Linn (S. rhombifolia) and evaluation of their antibacterial activities against four bacterial strains namely Staphylococcus aureus (DSMZ346), Escherichia coli (KL2DSM 498), Pseudomonas aeruginosa (DSMZ 1117) and Salmonella thyphimurium (ATCC 13311) employing agar disk diffusion method. Two compounds labeled as compounds SR-2 and SR-3 were isolated by subjecting the acetone crude extract of the dried fuits to column chromatography. The structures of the compounds were characterized using spectral analyses (IR and NMR spectroscopies) and comparing with literature reports. Compound SR-2 and compound SR-3 were proposed to be 1,3-dilinoleoyl-2-oleine and n-hexacosa-11- enoic acid, respectively. Compound SR-2 was isolated for the first time from this plant and its family whereas compound SR-3 was isolated from the root of this plant. In vitro antibacterial activity tests indicated that compound SR-3 is more active than compound SR-2 but less active than the reference compound (Gentamicine). Further antibacterial activity tests are required using other bacterial strains to decide the fate of the isolated compounds as drug leads.