Cembrane diterpenoids from the soft coral Sarcophyton trocheliophorum Marenzeller as a new class of PTP1B inhibitors

A detailed investigation of the South China Sea soft coral Sarcophyton trocheliophorum Marenzeller yielded, along with six known terpenes (6−11), the new sarcophytonolides N−R (1−5), whose structures have been elucidated by detailed spectroscopic analysis. Sarcophytonolides N-R are mono- or bicyclic cembranoids characterized by the presence of three/four double bonds and oxidized methyl groups. Some of the isolated compounds showed significant inhibitory activity against human protein tyrosine phosphatase 1B (PTP1B) enzyme, a key target for the treatment of type-II diabetes and obesity, and some preliminary structure-activity relationships have been drawn. This is the first report on the anti-PTP1B activity of cembrane diterpenoids.