PHYTOCHEMICAL INVESTIGATION AND ANTIMICROBIAL ACTIVITIES OF EXTRACT OF LEAF OF WITHANIA SOMNIFERA

Abstract

human ailments (the leaf part) including gastric, ulcers, colds and skin rashes in Ethiopia. In the present study, W.somnifera (Solaneceae) leaf extracts were investigated for their phytochemicals and antimicrobial activities. The qualitative analysis of n-hexane, chloroform: methanol (1:1), and methanol leaf extracts of the plant revealed the presence of flavonoids, terpenoids and phenols. The n-hexane extract of the leaf of the plant was esterified in order to convert fatty acid to methyl ester fatty acid. The esterified oil was characterized by GC-MS and identified twenty three compounds. From this there twelve are major compounds. These are benzyl nitrile (1.21%), dodecanioc acid (1.23%), decanoic acid (1.54%), hexadecanoic acid (1.80%), methyl tetra decanoate (2.75%), 7,10,13-hexadeca trienoic acid (3.15%), methyl 18-methyl nonadecanoate (3.69%), methyl stearate (4.10%), bis (2-ethylhexyl) phthalate (7.56%), penta decanoic acid, 13-methyl (13.44%), E,Z, 1,3,12-nonadecatriene (26.885) and 9-octadecenoic acid (Z) (27.095%). The crude extracts were tested against four bacteria species (two Gram positive bacteria, Staphylococcus aureus and Streptococcus agalactia; and two Gram negative bacteria, Escherichia coli and Salmonella typhi) and two fungal species (Aspergillus niger and Fusarium oxysporum) using paper disc diffusion method. The maximum antibacterial activity was shown in chloroform: methanol (1: 1) crude extract against salmonella typhi and E. coli (inhibition diameter 21.50 mm and 21.00 mm respectively). Whereas maximum antifungal activity was observed by chloroform: methanol (1: 1) crude extract against A. niger (23.50 mm) than Fusarium (18.60 mm). Therefore chloroform: methanol extract was significant in antimicrobial activities. Thus the present study supported the traditional claims of the plant.