Carbohydrates of the Milk of the Platypus

Abstract

Twelve samples of milk of the platypus, Ornithorhynchus anatinus, had a mean content of 3· 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 difucosyliactose, 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 4-0-acetyl-Nacetylneuraminlactose was detected by thin-layer chromatography. All milk samples examined contained protein material (probably glycoprotein), which was not precipitated by chloroformmethanol 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.

Physiology and Biochemistry of Lactation

“…and fucosyllactoses are particularly found (Messer, 1974;Kamerling et al, 1982;Messer et al, 1983), as well as a wide variety of oligosaccharides (Amano et al, 1985). However, only a little enzymology has been done.…”

2′-fucosyllactose: an abundant, genetically determined soluble glycan present in human milk

“…In contrast, 2′‐FL is either absent or present in low amounts in bovine and murine milk but appears early in mammalian phylogeny in monotremes. Table shows a summary of small molecular weight fucosylated oligosaccharides found in milk from different subclasses of mammals. At least three factors have to be taken into account when considering the data in this table: ) in most cases only a few samples of animal milk per species or subspecies have been analyzed; 2) it is unknown if the oligosaccharide repertoires in non‐human animals are as susceptible to individual variation as oligosaccharide profiles in human milk; and 3) different analytical methods have been used to determine oligosaccharide content in non‐human milk.…”

4-O-Acetyl-sialic acid (Neu4,5Ac2) in acidic milk oligosaccharides of the platypus (Ornithorhynchus anatinus) and its evolutionary significance

“…The MALDI-TOF MS spectrum ( Figure 4) [Hex] 3 (PM1-7-4). Messer et al (1983) and Amano et al (1985). Fig.…”

“…The platypus (Ornithorhynchus anatinus) resembles the echidna in that it lays eggs that are incubated for ∼10-11 days and its young hatch in a very immature state and depend on milk for a prolonged period (3-4 months; Grant and Griffiths 1992). However, prior studies of the platypus have been restricted to the neutral milk oligosaccharides (Messer and Kerry 1973;Messer et al 1983;Amano et al 1985). Nine structures that have been characterized are shown in Figure 1.…”