Antimicrobial activity of an endemic species, Thermopsis turcica, Turkey

Thermopsis turcica (Kit et al. 1983) is a medicinal wild growing plant endemic to Turkey. In this study, successive extracts of leaf, rhizome stem and callus extracts with n-hexane, ethyl acetate, methanol and diethyl ether were tested for antimicrobial activity against 8 strains of bacteria and 1 strain of fungus using disk diffusion and bioautography assays. As methanol extractions produced the highest crude extracts, alkaloids are the main metabolites of T. turcica. The results from the disc diffusion method showed that 100 /zg/ ml callus extracts of n-hexane, methanol and diethyl ether inhibited the growth of all tested microorganisms. In the bioautography assay, methanol extracts of rhizome stem and leaves produced the highest inhibition zones against. These results indicated thatthis endangered species has strong antimicrobial compounds against human pathogenic microorganisms, stressing the need for further investigations using fractionated extracts and purified chemical components.