Absolute stereochemistry and antitumor activity of iejimalides

The absolute configurations at five chiral centers, except for C-32(S) reported previously, in iejimalides A, C, and D, potent cytotoxic 24-membered macrolides isolated from a tunicate Eudistoma cf. rigida, were assigned as 4R, 9S, 17S, 22S, and 23S on the basis of detailed analysis of NMR data and chemical means. further-more, the Structures proposed for iejimalides A, C, and D were revised to their 13Z-isomers. Iejimalides A-D (1-4) exhibited antitumor activity in vivo. (c) 2005 Elsevier Ltd. All rights reserved.