Fractionation of antibacterial extracts of Syzygium cumini (Myrtaceae) seeds

Antibacterial activity of Syzygium cumini seed extracts prepared in methanol and ethanol was evaluated by disc diffusion and broth dilution assays. Both extracts exerted a broad spectrum of bacteriostatic action against different gram-positive and gram-negative bacteria. Their minimum inhibitory concentration (MIC) against susceptible organisms ranged from 154-656 μg/mL. Highest total activity was registered by the ethanol extract against Staphylococcus epidermidis. Extracts were separated on TLC (thin-layer chromatography) plates, and separated components were individually tested for their antibacterial activity. HPLC (high performance liquid chromatography) analysis indicated presence of gallic acid and quercetin in the methanolic extract.