Unusual minor nonmethylene-interrupted di-, tri-, and tetraenoic fatty acids in limpet gonads.

Unusual minor nonmethylene-interrupted (NMI) FA have been identified in the lipids of gonads from the limpets Cellana grata and Collisella dorsuosa by using GC-MS of the combination of their 4,4-dimethyloxazoline derivatives and picolinyl esters. Among 23 NMI unsaturated FA from C18 to C22 and C24 identified in this study, 5,11-nonadecadienoic (5,11-19:2), 7,1 6-heneicosadienoic (7,16-21:2), 9,15-tetracosadienoic (9,15-24:2), 5,9,15-docosatrienoic (5,9,15-22:3), and 5,9,15-tetracosatrienoic (5,9,15-24:3) acids may not have been reported previously from living organisms. The presence of 5,11,14,17-eicosatetraenonoic (5,11,14,17-20:4) and 7,13,16,19-docosatetraenenoic (7,13,16,19-22:4) acids as FA components in marine mollusks may be reported here for the first time. In this study, the male and female gonads of both species showed distinct differences in both their composition and proportions of NMI FA. Most NMI FA identified were mainly present in the female gonads of both species, especially in TAG that contained 21 NMI FA.