title: Unusual fatty acid isomers of triacylglycerols and polar lipids in female limpet gonads of Cellana grata.
abstract: To investigate the occurrence of positional isomers of unsaturated fatty acids (FA) in triacylglycerols (TAG) and polar lipids (PL) in the female gonads of a dominant limpet, Cellana grata, fatty acid methyl esters (FAME) were fractionated according to the degree of their unsaturation by argentation thin-layer chromatography. Their structures were elucidated by gas chromatography-mass spectrometry of a combination of their FAME and picolinyl esters. A total of 125 different FA ranging from 12 to 24 carbon atoms were identified, and 105 unsaturated FA, including 34 nonmethylene-interrupted FA as minor components, were recognized. Although the major FA 16:0 and 18:1n-7, which accounted for more than 20 and 10%, respectively, of total FA, were present in TAG and PL, higher amounts of 20:4n-6 and 20:5n-3 were present in PL. Unsaturated FA consisting of more than five different positional isomers were 17:1, 19:1, 18:2, 19:2, 20:2, 21:2, 22:2, 20:3, and 22:3, most of which were present in TAG. Furthermore, a larger variety of nonmethylene-interrupted FA was found in TAG than in PL. This limpet gonad had a diverse assortment of unsaturated FA that comprised a wide range of unusual positional isomers with one to five double bonds.
authors.affiliation: Bioscience Laboratory, Miyako College, Iwate Prefectural University, Miyako 027-0039, Japan. ajoe@iwate-pu.ac.jp
authors.forename: Hideki
authors.initials: H
authors.lastname: Kawashima
authors.forename: Masao
authors.initials: M
authors.lastname: Ohnishi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ogawa
authors.forename: Kenji
authors.initials: K
authors.lastname: Matsui
mesh_terms: D000818:Animals; D002384:Catalysis; D005227:Fatty Acids / Q000737:chemistry*; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D006066:Gonads / Q000737:chemistry*; D007536:Isomerism; D008055:Lipids / Q000737:chemistry*; D008974:Mollusca; D014280:Triglycerides / Q000737:chemistry*
chemical_list: D005227:Fatty Acids; D008055:Lipids; D014280:Triglycerides