Isolation of Antibacterial Compound from Ocimum sanctum (Tulsi) against Enteropathogenic Bacteria

Abstract

Hexane, petroleum ether, chloroform, ethyl acetate, acetone and methanol extracts of Tulsi (Ocimum sanctum) were analyzed for determination of antibacterial activity against enteric-pathogenic bacteria Escherichia coli, Shizella dysenteriae, Salmonella typhi, Pseudomonas aeruginosa and Vibrio cholerae using agar well diffusion method. Only acetone extract of all of them exhibited an inhibiting effect on the development of the tested strains. By using the disc diffusion method, the chosen pathogenic bacteria were examined for their pattern of antibiotic susceptibility.  A comparison of antibiotics and acetone extract was performed. It was discovered that  acetone extract found to be remarkable sensitivity against the test pathogens, total 37 fractions were obtained from the fractionization of acetone extract through column chromatography and found 4 major and 13minor compounds were obtained through Thin Layer Chromatography method. Antibacterial activity of different fractions was determined by spot assay technique. The fractions 1, 7, 13, and 21 demonstrated the greatest antibacterial activity when tested against the test pathogens out of all the fractions collected. Octadecanoic acid and methyl ester were found in the fraction number 13 according to the results of the Gas Chromatography Mass Specrometry.  Stearic acid methyl ester obtained from the acetone extract of Ocimum sanctum has been recommended for human trials against various bacterial infections.