Novel norsesterterpenes, which inhibit gastrulation of the starfish embryo, from the marine sponge Rhopaloeides sp.

✍ Scribed by Mihoko Yanai; Shinji Ohta; Emi Ohta; Susumu Ikegami

• Publisher: Elsevier Science
• Year: 1998
• Tongue: French
• Weight: 337 KB
• Volume: 54
• Category: Article
• ISSN: 0040-4020
• DOI: 10.1016/s0040-4020(98)01013-8

✦ Synopsis

Two new norsesterterpenes, rhopaloic acids B (2) and C (3), have been isolated from the marine sponge Rhopaloeides sp. together with the known rhopaloic acid A (1). Their structures have been elucidated by spectroscopic methods. Compounds 1, 2, and 3 potently inhibited gastrulation of the starfish (Asterina pectinifera) embryo, whereas hydrogenation or esterification resulted in loss of the inhibitory activity. Furthermore, methacrylic acid (9) did not affect embryonic development. These results suggest that the o~-exo-methylene carboxyl functionality attached to a tetrahydropyran ring is essential for the inhibitory activity of 1-3.