Fractionation of crude extracts from controlled dried and commercially available stem bark of Juglans regia and their antimicrobial effects

Abstract

The current research investigates the anti-microbial activities of methanol, ethyl acetate, n-hexane, n-butanol and water extracted samples from controlled dried and commercial bark of walnut (Juglans regia) against five bacterial (Staphylococcus aureus, Bacilus subtilis, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumonia and one fungal pathogenic specie (Candida albicans) by discs diffusion susceptibility assay using 0.5 and 1mg disc-1 concentrations. Our results revealed that all the extracts from controlled dried and commercial bark of walnut showed varying degrees of antimicrobial activities. Ethyl acetate fraction from both sources exhibited maximum activity against all tested microbial species followed by n-butanol and crude methanolic extraxt. N-hexane and aqueous extracted samples from controlled dried bark reduced the growth of all studied microbes except Staphylococcus aureus in case of commercial available bark. Aqueous extracted sample showed inhibitory effects against all tested microbes except Candida albicans respectively in case of commercial bark. The most susceptible gram positive bacteria were S. aureus while Bacillus subtilis was the most resistant one. Among Gram negative bacteria, Pseudomonas aeruginosa was the most susceptibility while Klebsella pneumonia showed some resistively. Compared to commercial bark samples, controlled dried bark extract and fractions were found to be more active in reducing the growth of all the tested microbes at both concentrations.