Comparative phytochemical and antimicrobial investigations of Hypericum perforatum L. subsp. perforatum and H....

The aerial parts of H. perforatum subsp. perforatum and H. perforatum subsp. angustifolium were investigated for their chemical composition and antimicrobial activity. Spectrophotometric analysis indicated that H. perforatum subsp. perforatum is richer in flavonoids and tannins than the other subspecies. HPLC analysis confirmed the higher yield of flavonoids in H. perforatum subsp. perforatum and gave also a higher content of phenolic acids. H. perforatum subsp. angustifolium contained more hypericin. The presence of rutin was proven only in H. perforatum subsp. perforatum. The antimicrobial activity of the extracts of both subspecies was evaluated based on the inhibition zone diameters using the hole-plate diffusion method. The MeOH extracts, dichloromethane and petroleum ether fractions were effective against Staphylococcus aureus, S. epidermidis, Enterococcus faecalis and Bacillus subtilis. The results indicate that H. perforatum subsp. angustifolium had a stronger antimicrobial effect than the other subspecies.