Bioassay-Guided Isolation of Antimicrobial Compound Against (Staphylococcus Aureus) from Azadirachta Indica PlantAuthor(s): I. O. Akpan, A. E. Ejele, R. E. Ogali, O. Achugasim and C. G. Osuagwu
The antimicrobial potential of crude extracts, and fractions obtained from Azadirachta indica have been evaluated. Phytochemical screening of the extracts and metabolites revealed the presence of tannins, saponins, flavonoids, steroids/triterpenes, glycosides, phenols, carboxylic acids, esters, aldehydes and ketones. The antimicrobial activities of crude extracts and their secondary metabolites were tested against some human pathogens: Staphylococcus aureus , Eschericha coli , Pseudomonas aeruginosa , Salmonella spp ., Candida spp ., Streptococcus spp . and Coliform spp . Of all the samples tested, the extract from the leaves and its secondary metabolites showed antimicrobial activity against one or more species of the microorganisms. Acidic metabolite of leaves of Azadirachta indica (ALA), which has the highest activity against Staphylococcus aureus was further subjected to chromatographic purification and antimicrobial analysis. Isolate of the chromatographic separation (ALA2), which showed best antimicrobial activity was assayed using NMR and IR techniques. The result of the analyses revealed that the antimicrobial compound in Azadirachta indica (A. indica) was a flavonoid glycoside probably naringin.