ent-kaurene diterpenoids from Isodon rubescens

Two kaurenoids, taibairubescensins A and B, were isolated from the ethanol extract of the leaves and branches of Isodon rubescens. Their structures are designated as 2 beta,3 beta-diacetoxy-11 beta,13 alpha-dihydroxy-ent-kaur-16-en-15-one and 3 beta,11 beta-diacetoxy-2 beta,6 alpha-dihydroxy-ent-kaur-16-en-15-one, respectively, on the basis of detailed spsctroscopic analyses. (C) 2000 Elsevier Science Ltd. All rights reserved.