Isolation of Antimicrobial Principle from Costus speciosus (Koen Ex. Retz.) Sm.

Costus speciosus (Koen Ex. Retz.) Sm. (Family-Costaceae) has been used in traditional medicine for the treatment of various human diseases. The antimicrobial activity of the ethanol extract of C. speciosus rhizome against standard bacterial and fungal strains along with the isolation of the active principle from the extract has been reported in the present work. The extract was observed to inhibit both bacteria and fungi and was found to be most effective against C. albicans (MIC = 0.012 mg/ml). The active component was isolated from the crude extract by preparative thin layer chromatography and it exhibited both antibacterial and antifungal activities. The antimicrobial component was characterized by FT-IR, LC–ESI–MS and H1-NMR spectral studies to be a long chain hydroxyester.