title: N-Methyltaurine N-acyl amidated bile acids and deoxycholic acid in the bile of angelfish (Pomacanthidae): a novel bile acid profile in Perciform fish.
abstract: Two novel N-acyl amidated bile acids, N-methyltaurine conjugated cholic acid and N-methyltaurine conjugated deoxycholic acid, were found to be major biliary bile acids in two species of angelfish the regal (Pygoplites diacanthus) and the blue-girdled (Pomacanthus navarchus) angelfish. The identification was based on their having MS and NMR spectra identical to those of synthetic standards. A survey of biliary bile acids of 10 additional species of angelfish found 7 with N-methyltaurine conjugation. In all 12 species, conjugated deoxycholic acid (known to be formed by bacterial 7-dehydroxylation of cholic acid) was a major bile acid. In all previous studies of biliary bile acids in fish, deoxycholic acid has been present in only trace proportions. In addition, bile acid conjugation with N-methyltaurine has not been detected previously in any known vertebrate. N-methyltaurine conjugated bile acids are resistant to bacterial deconjugation and dehydroxylation, and such resistance to bacterial enzymes should aid in the maintenance of high concentrations of bile acids during lipid digestion. Our findings suggest that these species of angelfish have a novel microbiome in their intestine containing anaerobic bacteria, and describe the presence of N-methyltaurine conjugated bile acids that are resistant to bacterial attack.
authors.affiliation: Department of Chemistry, College of Humanities & Sciences, Nihon University, Sakurajousui, Setagaya, Tokyo 156-8550, Japan.
authors.forename: Rika
authors.initials: R
authors.lastname: Satoh Née Okihara
authors.affiliation: Department of Chemistry, College of Humanities & Sciences, Nihon University, Sakurajousui, Setagaya, Tokyo 156-8550, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Saito
authors.affiliation: Department of Chemistry, College of Humanities & Sciences, Nihon University, Sakurajousui, Setagaya, Tokyo 156-8550, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Ogata
authors.affiliation: Department of Chemistry, College of Humanities & Sciences, Nihon University, Sakurajousui, Setagaya, Tokyo 156-8550, Japan.
authors.forename: Ayumi
authors.initials: A
authors.lastname: Ohsaki
authors.affiliation: Department of Chemistry, College of Humanities & Sciences, Nihon University, Sakurajousui, Setagaya, Tokyo 156-8550, Japan. Electronic address: takaiida@chs.nihon-u.ac.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Iida
authors.affiliation: Department of Marine Science and Resource, College of Bioresource Sciences, Nihon University, Kameino, Fujisawa, Kanagawa 274-8555, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Asahina
authors.affiliation: Faculty of Pharmaceutical Sciences, Kinki University, Kowakae, Higashi-Osaka 577-8502, Japan.
authors.forename: Kuniko
authors.initials: K
authors.lastname: Mitamura
authors.affiliation: Faculty of Pharmaceutical Sciences, Kinki University, Kowakae, Higashi-Osaka 577-8502, Japan.
authors.forename: Shigeo
authors.initials: S
authors.lastname: Ikegawa
authors.affiliation: Department of Medicine, University of California, La Jolla, San Diego, CA 92093-0063, USA.
authors.forename: Alan F
authors.initials: AF
authors.lastname: Hofmann
authors.affiliation: Department of Medicine, University of California, La Jolla, San Diego, CA 92093-0063, USA. Electronic address: LHagey@ucsd.edu.
authors.forename: Lee R
authors.initials: LR
authors.lastname: Hagey
mesh_terms: D000818:Animals; D001646:Bile / Q000737:chemistry*; D001647:Bile Acids and Salts / Q000032:analysis*; D003840:Deoxycholic Acid / Q000032:analysis*; D008968:Molecular Conformation; D010473:Perciformes / Q000378:metabolism*; D013045:Species Specificity; D013237:Stereoisomerism; D013654:Taurine / Q000031:analogs & derivatives / Q000032:analysis*
chemical_list: D001647:Bile Acids and Salts; D003840:Deoxycholic Acid; D013654:Taurine
keywords: (1)H detected heteronuclear multiple bond correlation; (1)H detected heteronuclear multiple quantum correlation; 2D-NMR; 3α,12α-dihydroxy-5β-cholan-24-oyl-N-methyltaurine; 3α,7α,12α-trihydroxy-5β-cholan-24-oyl-N-methyltaurine; 3α,7α-dihydroxy-5β-cholan-24-oyl-N-methyltaurine; 3α,7β-dihydroxy-5β-cholan-24-oyl-N-methyltaurine, lithocholyl-N-methyltaurine, 3α-hydroxy-5β-cholan-24-oyl-N-methyltaurine; Bile acid N-methyltaurine conjugate; Bile acid deconjugation; Bile acid dehydroxylation; Blue-girdled angelfish; CID; HMBC; HMQC; HR-MS; LC/ESI–MS/MS; RRT; Regal angelfish; chenodeoxycholyl-N-methyltaurine; cholyl-N-methyltaurine; collision-induced dissociation; deoxycholyl-N-methyltaurine; high-resolution mass spectrometry; liquid chromatography–electrospray ionization-tandem mass spectrometry; relative retention time; two-dimensional nuclear magnetic resonance; ursodeoxycholyl-N-methyltaurine