Antibacterial clerodane diterpenes from Goldenrod (Solidago virgaurea).

Abstract Nine clerodane diterpenes, solidagoic acids C-I ( 1 – 7 ), cleroda-3,13(14)-dien-16,15:18,19-diolide ( 8 ) and cleroda-3,13(14)-dien-15,16:18,19-diolide ( 9 ) were isolated and characterised from the ethanol–ethyl acetate (1:1) extract of Solidago virgaurea . The structures were determined by NMR spectroscopic analysis. Several displayed moderate antibacterial activity against Staphylococcus aureus .