title: Carbohydrates of the milk of the platypus.
abstract: Twelve samples of milk of the platypus, Ornithorhynchus anatinus, had a mean content of 3 X 3% hexose. Of this, almost half was L-fucose. Of the total monosaccharides present in acid hydrolysates of the water-soluble carbohydrates, L-fucose constituted 33%, D-galactose 29%, glucosamine 20%, D-glucose 11% and sialic acid 7%. Free lactose was found in only trace amounts. In all samples, the major oligosaccharide was difucosyllactose, which represented 39-52% of the total hexose. Five higher neutral oligosaccharides (from penta- to nonasaccharides) were isolated and their monosaccharide compositions determined. Each contained one or more residues of fucose, glucosamine and galactose and one residue of glucose. The presence in the milk of 4-O-acetyl-N-acetylneuraminlactose was detected by thin-layer chromatography. All milk samples examined contained protein material (probably glycoprotein), which was not precipitated by chloroform-methanol extraction. No evidence was obtained for quantitative or qualitative changes in carbohydrates during the course of the lactation season except for a small decline in total hexose towards the end of the season.
mesh_terms: D000818:Animals; D002241:Carbohydrates / Q000032:analysis*; D005260:Female; D006601:Hexoses / Q000032:analysis; D008892:Milk / Q000032:analysis*; D009007:Monotremata / Q000502:physiology*; D019158:N-Acetylneuraminic Acid; D010987:Platypus / Q000502:physiology*; D012794:Sialic Acids / Q000032:analysis
chemical_list: D002241:Carbohydrates; D006601:Hexoses; D012794:Sialic Acids; D019158:N-Acetylneuraminic Acid