title: Human excretory products of selenium are natural constituents of marine fish muscle.
abstract: A selenosugar (selenosugar 1, methyl-2-acetamido-2-deoxy-1-seleno-β-D-galactopyranoside) was identified in aqueous extracts of muscle tissue of three marine fish species, mackerel (Scomber scombrus), sardine (Sardina pilchardus), and tuna (Thunnus albacares), by high-performance liquid chromatography coupled to elemental and high-resolution molecular mass spectrometry. Selenoneine (2-selenyl-Nα, Nα, Nα-trimethyl-L-histidine), a known selenium compound in fish, was the major form of selenium in the aqueous extracts, and the methylated derivative of selenoneine, namely Se-methylselenoneine, was also identified as a minor natural constituent in the fish. Selenosugar 1, a major urinary excretion product of selenium often found in organs and body fluids related to selenium excretion, has so far not been reported in muscle tissue. Se-methylselenoneine has been proposed as the main urinary metabolite from selenoneine. This first report of selenosugar 1 and Se-methylselenoneine as natural constituents of fish muscle tissue opens up a new perspective on the role of these compounds in selenium metabolism and is relevant to selenium supplementation studies.
authors.affiliation: Institute of Chemistry, Analytical Chemistry, NAWI Graz, University of Graz, Universitaetsplatz 1, 8010, Graz, Austria.
authors.forename: Nina
authors.initials: N
authors.lastname: Kroepfl
authors.affiliation: Institute of Chemistry, Analytical Chemistry, NAWI Graz, University of Graz, Universitaetsplatz 1, 8010, Graz, Austria.
authors.forename: Kenneth B
authors.initials: KB
authors.lastname: Jensen
authors.affiliation: Institute of Chemistry, Analytical Chemistry, NAWI Graz, University of Graz, Universitaetsplatz 1, 8010, Graz, Austria.
authors.forename: Kevin A
authors.initials: KA
authors.lastname: Francesconi
authors.affiliation: Institute of Chemistry, Analytical Chemistry, NAWI Graz, University of Graz, Universitaetsplatz 1, 8010, Graz, Austria. doris.kuehnelt@uni-graz.at.
authors.forename: Doris
authors.initials: D
authors.lastname: Kuehnelt
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005399:Fishes / Q000378:metabolism*; D005690:Galactose / Q000032:analysis / Q000378:metabolism* / Q000652:urine*; D006639:Histidine / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism / Q000652:urine; D006801:Humans; D009132:Muscles / Q000378:metabolism; D016566:Organoselenium Compounds / Q000032:analysis / Q000378:metabolism* / Q000652:urine*
chemical_list: D016566:Organoselenium Compounds; C561546:Se-methylselenoneine; D006639:Histidine; D005690:Galactose
keywords: Fish muscle; HPLC-mass spectrometry; Se-methylselenoneine; Selenosugar