Two ring opened oxetane taxoids containing a C-20 benzoyloxy group from the roots of Taxus wallichiana Zucc.

Abstract Two new taxanes, named wallitaxane G ( 1 ) and H ( 2 ), were isolated from the roots of Taxus wallichiana (Taxaceae), together with nine known compounds ( 3 − 11 ). Their structures were elucidated on the basis of NMR spectroscopic analysis and the relative configurations of 1 and 2 were determined based on NOESY data. Wallitaxane H ( 2 ) showed the most potent α-glucosidase inhibitory activity, with an IC 50 value of 16.1 μM. Plausible biosynthetic pathways for the formation of 1 and 2 were proposed based on oxetane ring-opening and benzoyl migration.