NEW POLYPROPIONATES FROM SIPHONARIA-PECTINATA

The marine pulmonate Siphonaria pectinata contains the known polypropi onates pectinatone (1), siphonarienone (6), a mixture of C-4 epimers o f siphonarienedione (7), siphonarienolone (8), two independent mixture s of C-2 epimers of siphonarienfuranone (9) and the corresponding Z is omers (10), together with four new polypropionates, norsiphonarienone A (2), isosiphonarienolone (3), 2-deoxysiphonarienfuranone (4) and iso pectinatone (5). The structures of the new compounds were elucidated b y interpretation of spectral data. The polypropionates isolated from S . pectinata showed mild cytotoxicity against four tumor cell lines. (C ) 1997, Elsevier Science Ltd.