Flavonoids with activity against methicillin-resistant Staphylococcus aureus from Dalea scandens var. paucifolia

Bioassay-guided fractionation of the ethyl acetate extract of the roots of Dalea scandens (Miller) R. Clausen var. paucifolia led to the isolation of new flavonoids, 2(S)-5'-(-1''';1'''-dimethylallyl)-8-(3",3"-dimethylallyl)-2',4',5,7-tetrahydroxyflavanone, 2(S)-5'-(1''',1'''-dimethylallyl)-8-(3",3"-dimethyl allyl)-2'-methoxy-4',5,7-trihydroxyflavanone and 5'-(1''',1'''-dimethylallyl)-8-(3",3"-di-methyl allyl)-2',4',5,7-tetrahydroxyflavone. Structure elucidation was carried out by spectroscopic methods. All three compounds showed significant activity against both methicillin-susceptible and methicillin-resistant Staphylococcus aureus.