Bioactive Steroids from the Formosan Soft Coral Umbellulifera petasites.

Three new steroids, petasitosterones A and B ( and ) and a spirosteroid petasitosterone C (), along with eight known steroids (-), were isolated from a Formosan marine soft coral . The structures of these compounds were elucidated by extensive spectroscopic analysis and comparison of spectroscopic data with those reported. Compound is a marine steroid with a rarely found A/B spiro[4,5]decane ring system. Compounds - and displayed inhibitory activity against the proliferation of a limited panel of cancer cell lines, whereas and exhibited significant anti-inflammatory activity to inhibit nitric oxide (NO) production. The inhibitory activities for superoxide anion generation and elastase release of compounds - were also examined to evaluate the anti-inflammatory potential, and - were shown to exhibit significant activities.