Antineoplastic Agents. 520. Isolation and Structure of Irciniastatins A and B from the Indo-Pacific Marine Sponge Ircinia ramosa

Abstract
The Indo-Pacific marine sponge Ircinia ramosa has been found to contain two powerful (GI50 from 0.001 to -3−10-4% yields) by cancer cell line bioassay-guided techniques and named irciniastatins A (1) and B (2). Structural elucidation by a combination of spectral analyses, primarily high resolution mass and 2D-NMR (principally APT, HMQC, HMBC, and ROESY) spectroscopy, revealed the unusual structures 1 and 2.