A New Flavanone from Flemingia strobilifera (Linn) R. Br. and its Antimicrobial Activity

Purpose: To carry out a bioactivity guided fractionation and isolation of the antimicrobial constituent(s) of the roots of Flemingia strobilifera against some bacteria and fungi. Methods: The root of F. strobilifera was extracted with methanol, butanol and dichloromethane. Antimicrobial activity of the extracts was determined against both bacteria and fungi while the isolation and characterization of compounds of the extracts was done by column chromatography,2D spectroscopic studies and spectral data (U.V, I.R, NMR and MS). Results: Flemingiaflavanone (8, 3 ' -diprenyl-5, 7, 4 ' -trihydroxy flavanone), Genistin (5, 4 ' dihydroxy isoflavone 7-O-glucoside) and β - sitosterol-D glucoside were isolated from the extracts. Flemingiaflavanone showed significant antimicrobial activity against Gram-positive (S. aureus, S. epidermidis, MRSA), Gram-negative bacteria (Ps. aeruginosa, E. coli) and fungi (C. albicans). Genistin showed moderate activity against Gram-positive, Gram-negative bacteria and fungi. Conclusions: The isolation and antimicrobial activity of presence of Flemingiaflavanone is being reported for the first time.