Diterpenoids from Isodon calcicola var. subculva

Four new diterpenoids, calcicolins B-E, together with five known diterpenoids, calcicolin A, weisiensin A, adenanthin, forrestin C and nervosanin, have been isolated from the leaves of Isodon calcicola var. subculva. The new compounds were determined as 1 alpha, 3 beta-dihydroxy-7 beta, 11 beta-diacetoxy-ent-kaur-16-en-6,15-dione; la, 11 beta-diacetoxy-3 beta, 6 beta-dihydroxy-ent-kaur-16-en-15-one; 1 alpha, 6 alpha, 7 beta, 11 beta-tetraacetoxy-3 beta, 15 beta-dihydroxy-ent-kaur-16-ene, and 1 alpha, 6 alpha, 11 beta, 15 beta-tetra-acetoxy-3 beta, 7 beta-dihydroxy-ent-kaur-16-ene by means of spectrometry, including 2D NMR techniques. (C) 1998 Elsevier Science Ltd. All rights reserved