title: Novel di-, tri-, and tetraenoic fatty acids with bis-methylene-interrupted double-bond systems from the sponge Haliclona cinerea.
abstract: Unusual fatty acids, with up to 34 carbon atoms and containing one or two bis-methylene-interrupted double-bond systems, have been identified in the sponge Haliclona cinerea from the Black Sea. These include the dienes-5,9-16:2, 7,11-18:2, 9,13-20:2, 13,17-24:2, 15,19-26:2, 17,21-28:2, 19,23-30:2 and 21,25-32:2; trienes-5,9,23-30:3, 5,9,24-31:3, 5,9,25-32:3, and 5,9,27-34:3; and the tetraenes-5,9,19,23-30:4, 5,9,21,25-32:4, and 5,9,23,27-34:4. In addition, 5,9,13-eicosatrienoic acid was present. Many of these do not appear to have been described before, and only 5,9-16:2 and 5,9,23-30:3 are found often in sponges. They were identified by using silver-ion high-performance liquid chromatography to simplify the complex mixture of fatty acids for subsequent analysis by gas chromatography-mass spectrometry as picolinyl ester derivatives. Deuteration with Wilkinson's catalyst in homogeneous solution confirmed the structures. We speculate that the di- and tetraenoic fatty acids arise by chain elongation of 5,9-hexadecadienoic acid, also a major component of the lipids, followed by further insertion of double bonds in the 5 and 9 positions. The trienes may be formed from 9-hexadecenoic acid by similar mechanisms.
authors.affiliation: Department of Food Science and Nutrition, Dong-A University, Pusan, Korea.
authors.forename: Y G
authors.initials: YG
authors.lastname: Joh
authors.forename: I J
authors.initials: IJ
authors.lastname: Elenkov
authors.forename: K L
authors.initials: KL
authors.lastname: Stefanov
authors.forename: S S
authors.initials: SS
authors.lastname: Popov
authors.forename: G
authors.initials: G
authors.lastname: Dobson
authors.forename: W W
authors.initials: WW
authors.lastname: Christie
mesh_terms: D000818:Animals; D002031:Bulgaria; D002851:Chromatography, High Pressure Liquid; D005227:Fatty Acids / Q000032:analysis* / Q000737:chemistry; D005231:Fatty Acids, Unsaturated / Q000032:analysis / Q000096:biosynthesis / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D008055:Lipids / Q000737:chemistry / Q000302:isolation & purification; D010848:Picolinic Acids; D011161:Porifera / Q000737:chemistry*
chemical_list: D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D008055:Lipids; D010848:Picolinic Acids