Novel Non‐methylene‐Interrupted Dienoic and Trienoic Fatty Acids with a Terminal Double Bond in Ovaries of the Limpet Cellana toreuma

Abstract

In this study, to obtain further information on the structural diversity of non-methylene-interrupted (NMI) fatty acids (FA) in the gonads of the limpet Cellana toreuma, previously unreported minor NMI FA, fractionated by argentation thin-layer chromatography (TLC), in the ovaries were characterized by gas chromatographymass spectrometry (GC-MS) analysis of their 3-pyridylcarbinol derivatives. As a result, five novel NMI FA were identified as 5,14-pentadecadienoic acid (15: 2Δ5,14), 5,9,18-nonadecatrienoic acid (19:3Δ5,9,18), 5,9,20-heneicosatrienoic acid (21:3Δ5,9,20), 7,13,20-heneicosatrienoic acid (21:3Δ7,13,20), and 5,9,22-tricosatrienoic acid (23:3Δ5,9,22). Possible biosynthetic pathways for these FA are also discussed in relation to structural variations of NMI FA regioisomers. This study clearly reinforces the findings of our previous works with structurally diverse NMI FA with a terminal double bond. Keywords 3-Pyridylcarbinol derivatives Á Cellana toreuma Á Limpet Á Non-methylene-interrupted fatty acid Á Odd-chain fatty acid Á Terminal double bond Lipids (2020) 55: 285-290. Abbreviations ECL equivalent chain length EI electron impact FA fatty acid(s) FAME fatty acid methyl ester(s) GC-MS gas chromatography-mass spectrometry GLC gas-liquid chromatography MS mass spectrum NMI non-methylene-interrupted PtdCho phosphatidycholine PtdEtn phosphatidyethanolamine TAG triacylglycerols TLC thin-layer chromatography