New Cembranoid Diterpenes from the Cultured Octocoral Nephthea columnaris

摘要

Two new 15-hydroxycembranoid diterpenes, 2β-hydroxy-7β,8α-epoxynephthenol (>1) and 2β-hydroxy-11α,12β-epoxynephthenol (>2), were isolated from extracts of the octocoral Nephthea columnaris along with a new natural cembrane, epoxynephthenol (>3) and a known sterol, nephalsterol A (>4). The structures of cembranes >1–>3 were elucidated by spectroscopic methods and comparison of the spectroscopic data with those of related analogues. The cytotoxicity of metabolites >1–>4 against a panel of tumor cells is also described.