Chemical and antibacterial evaluation of Hypericum triquetrifolium Turra.

Five extracts and pure compounds from the aerial parts of Hypericum triquetrifolium were tested for their antibacterial activity against 31 gram-positive and gram-negative strains using the agar dilution method (Lorian). The ethyl acetate extract exhibited a weak antibacterial activity against Staphylococcus strains, and pure constituents such as quercetin and I3,II8-biapigenin were the active components of this extract.