Two novel sesquiterpenes from the roots of Taiwania cryptomerioides Hayata

Two novel 3,4-secocadinane and 4,5-seco-8(7→6)-abeoguaiane skeletons, namely taiwaninones A (1) and B (2), together with khusinodiol (3) and 4β,6β-dihydroxy-1α,5β(H)-guai-9-ene (4) were isolated from the roots of Taiwania cryptomerioides. Their structures were elucidated by the spectral methods. The biotransformations of 1 and 2 were proposed from 3 and 4, respectively.