A new diterpene and bioactivities of labdanes isolated from Buddleja marrubiifolia.

The new labdane [(3R*,4aR*,7S*,10aS*,10bR*)-3-ethenyl-3,4a,7,10a-tetramethyl-dodecahydro-1H-naphtho-[2,1-b]-pyran-7-yl]-methylbenzoate together with other 7 labdanes were isolated from the aerial parts of Buddleja marrubiifolia. Compound structures were elucidated by spectroscopic methods. Some compounds showed moderate to weak antimicrobial activity towards a panel of bacterial and fungal pathogens. In addition, trans-biformene (2) and ribenol acetate (8) showed to be highly cytotoxic with LC50 < 1 µg/mL, the other compounds showed moderate cytotoxic effect with a LC50 range of 6.008-15.26 µg/mL. For all isolated compounds, no inflammatory response was observed.