7,8β-dihydroponasterone A, a new phytoecdysteroid from the needles of the Japanese yew, Taxus cuspidata

A new plant ecdysteroid 7,8 beta-dihydroponasterone A, together with ponasterone A, were isolated from the methanol extract of the needles of the Japanese yew, Taxus cuspidata. Their structures were elucidated on the basis of spectroscopic analysis including H-1 NMR, C-13 NMR, H-1-H-1 COSY, NOESY, HMQC and HMBC and confirmed by high-resolution FABMS data.