Occurrence of all-cis-5,8,11,14,17,20,23-hexacosaheptaenoic acid (26:7n-3) in roughscale sole Clidoderma asperrimum flesh lipids

• Published in: Fisheries science Vol. 77; no. 5; pp. 875 - 882
• Main Authors: Fukuda, Yuuki, Ando, Yasuhiro
• Format: Journal Article
• Language: English
• Published: Japan Springer Japan 01.09.2011; Springer Nature B.V
• Subjects: Algae; Biomedical and Life Sciences; Chromatography; Clidoderma asperrimum; Fatty acids; Fish & Wildlife Biology & Management; Fisheries; Fishery sciences; Food Science; Freshwater & Marine Ecology; Gas chromatography; Hydrogenation; Life Sciences; Lipids; Marine; Mass spectrometry; Nitrates; Original Article; Polyunsaturated fatty acids; Sensors; Solvents; Studies; Thin layer chromatography; Very long-chain polyunsaturated fatty acid; GC–MS; Roughscale sole; GC; Fatty acid; Hexacosaheptaenoic acid
• ISSN: 0919-9268; 1444-2906
• DOI: 10.1007/s12562-011-0387-y

Fatty acid analysis of roughscale sole Clidoderma asperrimum flesh lipids was carried out by gas chromatography. An unidentified peak appeared in the chromatogram in the elution region of ≥C24 fatty acids. After enrichment by solvent partitioning, reversed-phase thin-layer chromatography (TLC), and argentation TLC, the peak component was subjected to structural analyses. The partially hydrogenated products after reaction with hydrazine hydrate gave seven isomers of cis -hexacosenoic acid (26:1). Gas chromatography-mass spectrometry (GC–MS) analyses of their dimethyl disulfide adducts identified the monounsaturates as 5-, 8-, 11-, 14-, 17-, 20-, and 23-26:1. The peak component was assigned to all- cis -5,8,11,14,17,20,23-hexacosaheptaenoic acid (26:7n-3). GC–MS analyses of the 4,4-dimethyloxazoline derivative and methyl ester confirmed this structure. This fatty acid is a rare, very long-chain polyunsaturated fatty acid (VLCPUFA). The concentrations of the acid found in roughscale sole were 0.69 ± 0.34% ( N  = 5) of total fatty acids in flesh lipids. Roughscale sole appears to be characterized by the occurrence of 26:7n-3, which is lacking in popular sources of methylene-interrupted VLCPUFA, such as vertebrate retina, spermatozoa, and herring.