title: Chemical characterization of the oligosaccharides in milk of high Arctic harbour seal (Phoca vitulina vitulina).
abstract: Carbohydrates were extracted from high Arctic harbour seal milk, Phoca vitulina vitulina (family Phocidae). Free neutral oligosaccharides were separated by gel filtration and preparative thin layer chromatography, while free sialyl oligosaccharides were separated by gel filtration and then purified by ion exchange chromatography, gel filtration and high performance liquid chromatography. Oligosaccharide structures were determined by 1H-NMR spectroscopy. The structures of the neutral oligosaccharides were as follows: lactose, 2'-fucosyllactose, lacto-N-neotetraose, lacto-N-neohexaose, monofucosyl lacto-N-neohexaose and difucosyl lacto-N-neohexaose. Thus, all of the neutral saccharides contained lactose or lacto-N-neotetraose or lacto-N-neohexaose as core units and/or non-reducing alpha(1-2) linked fucose. These oligosaccharides have also been found in hooded seal milk. The structures of the silalyl oligosaccharides were: monosialyl lacto-N-neohexaose, monosialyl monofucosyl lacto-N-neohexaose, monosialyl difucosyl lacto-N-neohexaose and disialyl lacto-N-neohexaose. These oligosaccharides contained lacto-N-neohexaose as core units, and one or two alpha(2-6) linked Neu5Ac, and/or non-reducing alpha(1-2) linked Fuc. The Neu5Ac residues were found to be linked to GlcNAc or penultimate Gal residues. The acidic oligosaccharides are the first to have been characterized in the milk of any species of seal.
authors.affiliation: Department of Bio Resource Science, Obihiro University of Agriculture and Veterinary Medicine, Inada cho, Obihiro, Hokkaido 080-8555, Japan. urashima@obihiro.ac.jp
authors.forename: Tadasu
authors.initials: T
authors.lastname: Urashima
authors.forename: Tadashi
authors.initials: T
authors.lastname: Nakamura
authors.forename: Kohsuke
authors.initials: K
authors.lastname: Yamaguchi
authors.forename: Jiro
authors.initials: J
authors.lastname: Munakata
authors.forename: Ikichi
authors.initials: I
authors.lastname: Arai
authors.forename: Tadao
authors.initials: T
authors.lastname: Saito
authors.forename: Christian
authors.initials: C
authors.lastname: Lydersen
authors.forename: Kit M
authors.initials: KM
authors.lastname: Kovacs
mesh_terms: D000818:Animals; D005260:Female; D009682:Magnetic Resonance Spectroscopy; D008892:Milk / Q000737:chemistry*; D009844:Oligosaccharides / Q000032:analysis / Q000737:chemistry*; D011522:Protons; D046048:Seals, Earless / Q000378:metabolism*
chemical_list: D009844:Oligosaccharides; D011522:Protons