A new bis-γ-pyrone polypropionate of onchidiol family from marine pulmonate mollusk sp.

A new bis-γ-pyrone polypropionate, 4,16-di--onchidiol (), along with three known related compounds (-) were isolated from the marine pulmonate mollusk sp. The structure of compound was elucidated by extensive spectroscopic analysis and by comparison the NMR data with its stereoisomers -, whereas its absolute configuration was determined by the combination of X-ray diffraction analysis and TDDFT-ECD calculation. In bioassay, the isolated compounds exhibited broad cytotoxicity against several cancer cell lines with IC values ranging from 24.6 to 88.5μM.