Pintoxolanes A–C, Highly Functionalized 3,14‐Oxa‐bridged Cembranoids from the Caribbean Gorgonian Coral Eunicea pinta

Three new cembrane‐based diterpenes possessing the rare 3,14‐oxa‐bridged moiety were isolated from the hexane extract of a southwestern Caribbean gorgonian octocoral, Eunicea pinta , together with seven known cembranoid diterpenes. The structures of pintoxolanes A–C ( 1 – 3 , resp.), including their relative configurations, were deduced from spectroscopic data and chemical‐correlation experiments. Experimental evidence hinting to a plausible biogenesis of the 3,14‐oxalane moiety is provided. Preliminary cytotoxicity data for compounds 1 – 3 toward human cancer cell lines are also provided.