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"-dimethylallyl)-2'-methoxy-4',5,7-trihydroxyflavanone and 5'-(1"',1"'-dimethylallyl)-8-(3",3"-dimethylallyl)-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.