Austrodorin-A and -B: first tricyclic diterpenoid 2 '-monoglyceryl esters from an Antarctic nudibranch

Two novel diterpenoid 2'-monoglyceryl esters, austrodorin-A (7) and austrodorin-B (8), which contain the isocopalane skeleton with an uncommon oxygenated substitution pattern, have been isolated from the skin of the Antarctic nudibranch Austrodoris kerguelenensis. Structures and relative stereochemistries have been established by NMR methods, whereas the absolute configuration was suggested by comparison of their CD profiles with those of model compounds. (C) 1999 Elsevier Science Ltd. All rights reserved.