N-glycolylneuraminic acid

N-glycolylneuraminic acid, also called Neu5Gc, is a colourless solid with the molecular formula: C11H19NO10 which belongs to the class of sialic acids (N-acetylneuraminic acids).

In animal organisms the N-glycolylneuraminic acid is a frequently occurring sialic acid. However, the human organism is not able to produce it.

In humans, only N-acetylneuraminic acid is present because the enzyme CMP-Neu5Ac-hydroxylase, which catalyses the formation of N-glycolylneuraminic acid from N-acetylneuraminic acid, is not functional in humans.

Humans form antibodies against this sialic acid when they come into frequent contact with animals. In a larger study (PARSIFAL), it could be shown that higher AK levels are found in children who grow up on farms than in non-farm children. The level of AK is inversely correlated with the incidence of wheezing, bronchial asthma and colitis.

1. Frei R et al (2018) Exposure to nonmicrobial N-glycolylneuraminic acid protects farmers' children against airway inflammation and colitis. J Allergy Clin Immunol 141:382-390.