The main oligosaccharide (50%) in the milk of the Australian echidna (Tachyglossus aculeatus) has been identified unequivocally as 4-O-acetyl-α-N-acetylneur-amínyl-(2→3)-lactose. The 4-O-acetyl substituent of the sialic acid residue was characterised by g.l.c.-m.s. of the isolated (after mild, acid hydrolysis) and trimethyl-silylated/esterified sialic acid, and by m.s. (after derivatisation) and 500-MHz, 1H-n.m.r. spectroscopy of the intact oligosaccharide. Information about the glycosidic bonds was obtained by methylation analysis and 500-MHz, 1H-n.m.r. spectroscopy. This animal species is the third one known to produce 4-O-acetylated sialic acid. © 1982.
Kamerling, J. P., Dorland, L., van Halbeek, H., Vliegenthart, J. F. G., Messer, M., & Schauer, R. (1982). Structural studies of 4-O-acetyl-α-N-acetylneuraminyl-(2→3)-lactose, the main oligosaccharide in echidna milk. Carbohydrate Research, 100(1), 331–340. https://doi.org/10.1016/S0008-6215(00)81046-0