title: Isolation of 2-methyl branched unsaturated very long fatty acids from marine sponge Halichondria panicea and identification of them by GC-MS and NMR.
abstract: In order to study the biomarker fatty acids of symbionts in the marine sponge Halichondria panicea, purification and structural identification of two new 2-methyl branched monoenoic very long fatty acids (2-Me-24:1 n-7 and 2-Me-26:1 n-9) were performed for the first time. These acids amounted to 7.1% of total sponge FAs, but our attempts to determine their structures by one-step GC-MS analysis were unsuccessful because of low yields of the correspondent N-acyl pyrrolidide derivatives. Silver-ion thin-layer chromatography isolated enriched fractions of monoenoic fatty acids extracted from the sponge. Further purification of unknown fatty acid methyl esters was carried out by reversed-phase high-performance liquid chromatography. Determination of the chain length, degree and position of unsaturations was achieved by gas chromatography-mass spectrometry on methyl esters and dimethyldisulfide adducts. Structures, position of methyl substitution, and double bonds cis isomery were confirmed by 1H nuclear magnetic resonance.
authors.affiliation: Institute of Marine Biology, Far Eastern Branch of Russian Academy of Sciences, Palchevskogo 17, 690041 Vladivostok, Russia. andreyimbs@hotmail.com
authors.forename: Andrey B
authors.initials: AB
authors.lastname: Imbs
authors.forename: Svetlana A
authors.initials: SA
authors.lastname: Rodkina
mesh_terms: D000818:Animals; D005231:Fatty Acids, Unsaturated / Q000737:chemistry* / Q000302:isolation & purification; D008401:Gas Chromatography-Mass Spectrometry; D009682:Magnetic Resonance Spectroscopy; D011161:Porifera / Q000737:chemistry*
chemical_list: D005231:Fatty Acids, Unsaturated