[Show abstract][Hide abstract] ABSTRACT: A detailed structural diversity of dienoic fatty acids (FA), including non-methylene-interrupted dienoic FA, of triacylglycerols and polar lipids in ovaries of Cellana toreuma was clarified for the first time by using capillary gas chromatography-mass spectrometry of their 3-pyridylcarbinol esters and argentation thin-layer chromatography. Interestingly, in addition to 5,9-octadecadienoic (18:2Δ5,9), 5,9-eicosadienoic (20:2Δ5,9), 5,9-heneicosadienoic (21:2Δ5,9), 5,9-docosadienoic (22:2Δ5,9), 5,9-tricosadienoic (23:2Δ5,9), and 5,9-tetracosadienoic (24:2Δ5,9) acids, previously identified in ovaries of C. grata, rare FA 5,9-hexadecadienoic (16:2Δ5,9), 5,9-nonadecadienoic (19:2Δ5,9), and 21-methyl-5,9-docosadienoic (iso 23:2Δ5,9) were newly recognized in ovaries of C. toreuma. Detectable amounts of four Δ9,15-dienoic FA were present in the ovary lipids. The FA identified were one novel 9,15-heneicosadienoic (21:2Δ9,15) acid and known 9,15-docosadienoic (22:2Δ9,15), 9,15-tricosadienoic (23:2Δ9,15), and 9,15-tetracosadienoic (24:2Δ9,15) acids. The findings help to explain the broad evidence of the structural diversity in marine gastropods and suggest biomarkers to evaluate marine food web relations.
[Show abstract][Hide abstract] ABSTRACT: In the present study, we show that four unusual cholesterol precursors, 5α-cholesta-8,14-dien-3β-ol, 4-methyl-5α-cholesta-8,24-dien-3β-ol (4-methylzymosterol), 4,4,14-trimethyl-5α-cholesta-8,24-dien-3β-ol (lanosterol), and 4,4-dimethyl-5α-cholesta-8,24-dien-3β-ol (4,4-dimethylzymosterol) are present in testes of the limpet Cellana grata, which is part of one of the most primitive gastropod families (Nacelllidae Family). The distribution of these sterols in testes and ovaries of four dominant species of limpets, Cellana grata, Cellana toreuma, Nipponacmea concinna, and Nipponacmea fuscoviridis, was examined by capillary gas chromatography-mass spectrometry. Based on the data, we discuss about the biological roles and possible application as bio-resources of these sterols. This is the first identification of 5α-cholesta-8, 14-dien-3β-ol, 4-methylzymosterol, and 4,4-dimethylzymosterol in marine invertebrate gonads.
No preview · Article · Jul 2013 · Journal of oleo science
[Show abstract][Hide abstract] ABSTRACT: To investigate unusual odd-chain fatty acids (FA) from gonads of archaeogastropods, limpets Cellana grata and Cellana toreuma, a subfraction enriched in FA with two double bonds extracted from the gonads was obtained by using argentation thin-layer chromatography. The resulting fraction was analyzed by using capillary gas chromatography-mass spectrometry of its methyl esters, 3-pyridylcarbinol esters and pyrrolidide derivatives. Six novel all-cis diene isomers were identified as 7,18-heneicosadienoic (21:2Δ7,18), 8,14-tricosadienoic (23:2Δ8,14), 9,15-tricosadienoic (23:2Δ9,15), 7,18-tricosadienoic (23:2Δ7,18), 9,18-tricosadienoic (23:2Δ9,18), and 9,20-tricosadienoic (23:2Δ9,20) acids. In the present study, the differences in the proportion of tricosadienoic acid isomers between the ovary lipids of C. grata and C. toreuma were recognized.
[Show abstract][Hide abstract] ABSTRACT: This is the first report on the sterol composition in Nipponacmea concinna and Nipponacmea fuscoviridis, 2 dominant species of lottiid limpets. There were significant differences in sterol composition between male and female gonads of the limpets. Previous studies have shown that zymostenol and zymosterol are major lipid components of male gonads of the nacellid limpets Cellana grata and Cellana toreuma. In contrast, in this study, only trace amounts of zymosterol were detected in male gonads of N. fuscoviridis.
No preview · Article · Oct 2011 · Journal of oleo science
[Show abstract][Hide abstract] ABSTRACT: The present study demonstrated here for the first time that there are statistically significant differences in sterol composition between male and female gonads of the dominant limpets Cellana grata and Cellana toreuma, which are intertidal gastropods. Among 11 different sterols identified in this study, unusually high levels (11.2-19.8% of total sterols) of the Delta8-sterols 5alpha-cholest-8-en-3beta-ol (zymostenol) and 5alpha-cholesta-8,24-dien-3beta-ol (zymosterol), which have never been reported in aquatic invertebrate gonads, were present in only the male gonads.
[Show abstract][Hide abstract] 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.
[Show abstract][Hide abstract] ABSTRACT: Sterol composition in muscle and viscera tissues of the marine bivalve Megangulus zyonoensis was investigated. Among 13 different sterols identified by gas chromatography-mass spectrometry of their trimethylsilyl ether derivatives, cholesterol was the most abundant sterol, followed by 24-methylenecholesterol, in both muscle and viscera tissues. In this study, the proportion of brassicasterol, in addition to that of cholesterol, differed between the muscle and viscera.
No preview · Article · Feb 2007 · Journal of oleo science
[Show abstract][Hide abstract] ABSTRACT: The occurrence of positional isomers of minor C(24) unsaturated fatty acids in female gonad lipids of the limpet Cellana grata was clarified by gas chromatography-mass spectrometry of the combination of their 4,4-dimethyloxazoline and picolinyl ester derivatives. In this study, in addition to 5,9-24:2, 9,15-24:2, 5,9,15-24:3, and 5,9,17-24:3, previously identified, 24:4n-6, 24:5n-3, and four novel nonmethylene-interrupted fatty acids, 9,17-24:2, 9,15,18-24:3, 5,9,15,18-24:4, and 5,9,15,18,21-24:5, were newly recognized. All C(24) unsaturated fatty acids detected were present only in triacylglycerols.
No preview · Article · Nov 2006 · Bioscience Biotechnology and Biochemistry
[Show abstract][Hide abstract] ABSTRACT: 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.
[Show abstract][Hide abstract] ABSTRACT: To clarify the occurrence of nonmethylene-interrupted (NMI) FA in the marine bivalve Megangulus zyonoensis, methyl esters of unsaturated FA were fractionated according to the degree of their unsaturation by using argentation TLC. Their structures were elucidated by using GC-MS of their FAME and 2-alkenyl-4,4-dimethyloxazoline derivatives. Seventy-two unsaturated FA, including the novel 7,15-21 and 20:4n-1, were identified. The unusual tetraenoic acids 20:4n-4, 20:4n-1, 21:4n-6, and 21:4n-5 were found in M. zyonoensis. This bivalve was extremely rich in the positional isomers of 19:1, 20:2, and 20:3. The distribution of NMI and positional isomers of unusual FA in the bivalve tissues was also discussed.