Dolabelides C and D, Cytotoxic Macrolides Isolated from the Sea Hare <i>Dolabella auricularia</i>

Abstract

Two new cytotoxic 24-membered macrolides, dolabelides C and D, were isolated from the Japanese sea hare Dolabella auricularia. Their gross structures were deduced by spectroscopic analysis including the 2D NMR technique, and their absolute stereochemistry was determined by means of chemical correlation with the known dolabelide A. Dolabelides C and D exhibited cytotoxicities against HeLa S3 cells with IC50 values of 1.9 and 1.5 μg/mL, respectively.