title: Generation of Tetracosahexaenoic Acid in Benthic Marine Organisms.
abstract: Tetracosahexaenoic acid (THA, 24:6n-3) has been shown to have the strongest ability to suppress accumulation of lipids in HepG2 cells among well-known n-3 highly unsaturated fatty acids, such as EPA and DHA. In this study, a method for mass production of THA was investigated using distributions of THA and DHA in thirty-two marine organisms, such as starfishes, right-eyed flounders, shellfishes, and sharks. The fatty acid composition of the marine organisms was analyzed using GC-FID and THA was detected in starfish, right-eyed flounder, and shark. Furthermore, the ratio of DHA and THA (DHA/THA) in each sample was calculated using chromatogram peak area of GC-FID, and the value was found to be lower than 1 in some starfishes. As a result, THA was thought to be synthesized in the starfishes. In contrast, the value of DHA/THA for right-eyed flounder and sharks was greater than 1. The THA accumulation in right-eyed flounder was considered to be because of the starfishes that the flounder consumes as part of its diet. DHA is synthesized from THA by beta-oxidation in peroxisomes, in the Sprecher's shunt. The high accumulation of THA observed in the flounder would be caused by the decreasing enzyme activation due to beta-oxidation in the peroxisomes of the starfishes. Understanding the differences in THA between aquatic species could also potentially allow us to understand why THA is generated in marine animals.
authors.affiliation: Department of Food Science and Technology, Tokyo University of Marine Science and Technology.
authors.forename: Rei
authors.initials: R
authors.lastname: Suo
authors.forename: Haoqi
authors.initials: H
authors.lastname: Li
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Yoshinaga
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Nagai
authors.forename: Hoyo
authors.initials: H
authors.lastname: Mizobe
authors.forename: Koichi
authors.initials: K
authors.lastname: Kojima
authors.forename: Koji
authors.initials: K
authors.lastname: Nagao
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Beppu
authors.forename: Naohiro
authors.initials: N
authors.lastname: Gotoh
mesh_terms: D000818:Animals; D004281:Docosahexaenoic Acids / Q000032:analysis / Q000096:biosynthesis / Q000378:metabolism*; D005227:Fatty Acids / Q000032:analysis; D005432:Flounder / Q000378:metabolism*; D050356:Lipid Metabolism; D008974:Mollusca / Q000378:metabolism*; D010084:Oxidation-Reduction; D020675:Peroxisomes / Q000378:metabolism; D012754:Sharks / Q000378:metabolism*; D013215:Starfish / Q000378:metabolism*
chemical_list: D005227:Fatty Acids; D004281:Docosahexaenoic Acids; C099831:tetracosahexaenoic acid