N-乙酰-神经氨酸, 唾液酸

N-Acetylneuraminic acid

Sialic acid (Neu5Ac) is a nine-carbon monosaccharide (a 2-keto-carboxylic acid, a deoxysugar, and an aminosugar). The amino group is generally N-acetylated (5-acetamido-3,5-dideoxy-d-glycero-d-galacto-non-2-ulopyranosonic acid, N-acetylneuraminic acid, Neu5Ac) (Collins, 2006). Sialic acid is found across the animal kingdom and some prokaryotes. Sialic acid occurs as a component of oligosaccharides (N- and O-linked glycoproteins, glycolipids, human milk, blood groups), bacterial polysaccharides and glycoconjugates. Sialic acid is also found in free form in body fluids (Schauer, 1997).

Salic acids are nine-carbon carbohydrate α-keto acids that have many important biological functions, including cell-cell recognition and host-pathogen interactions. N-Acetylneuraminic acid (NANA) is the most abundant sialic acid and is found in bacteria as well as in eukaryotic cells. The pathways for NANA synthesis and metabolism in bacteria differ from those used in eukaryotic cells. This sialic acid is an essential component of human brain gangliosides and sialylated glycoproteins.

N-acetylneuraminic acid is an N-acylneuraminic acid where the N-acyl group is specified as acetyl. It has a role as an antioxidant, an EC 3.2.1.18 (exo-alpha-sialidase) inhibitor, a bacterial metabolite, a human metabolite and a mouse metabolite. It is a conjugate acid of a N-acetylneuraminate.

An N-acyl derivative of neuraminic acid. N-acetylneuraminic acid occurs in many polysaccharides, glycoproteins, and glycolipids in animals and bacteria. (From Dorland, 28th ed, p1518)