Diterpenoids and steroids from Taiwania cryptomerioides

Five new diterpenes and four uncommon sterols were isolated from the leaves of Taiwania cryptomerioides. Their structures were determined by chemical, spectroscopic and X-ray diffraction methods. The terpenes are 8,9-epoxy-7-oxoroyleanone methyl ether, 1,13,14-trihydroxypodocarpa-8,1 1,13-trien-7-one, 7 alpha,8 alpha-dihydroxylabda-13(16),14-dien-19-yl cis-4-hydroxycinnamate, 7 alpha,8 alpha-dihydroxylabda-13(16),14-dien-19-yl tians-4-hydroxycinnamate and beyer-15-en-l 8-carboxy beta-D-glucopyranoside pentaacetate. The sterols, namely taiwaniasterols A-D, exhibit an uncommon skeleton of 6-5-6-5 fused rings. (C) 1998 Elsevier Science Ltd. All rights reserved.