Deoxycholyl

Deoxycholyl is a chemical moiety derived from deoxycholic acid, a secondary bile acid produced in the intestine and a component of bile. In biochemical naming, deoxycholyl denotes the deoxycholic acid residue when it is linked to amino acids such as glycine or taurine to form conjugates. Common conjugates include glycodeoxycholate and taurodeoxycholate, in which the deoxycholyl skeleton is joined to glycine or taurine, respectively.

Chemically, deoxycholic acid is a 24-carbon sterol with the core cholane structure bearing hydroxyl groups at the 3α and 12α positions and a terminal carboxyl group. Its conjugates with amino acids increase solubility and facilitate intestinal transport. The molecular formula of deoxycholic acid is C24H40O4. In physiological conditions, the deoxycholyl moiety can exist as the free acid, the deprotonated salt (deoxycholate), or as part of conjugates with glycine or taurine.

Biosynthesis and occurrence: deoxycholic acid is formed in the gut by bacterial 7α-dehydroxylation of cholic acid. It is subsequently secreted into bile and participates in fat digestion. Through enterohepatic circulation, deoxycholic acid and its conjugates are reabsorbed in the ileum and return to the liver for reuse.

Physiological role and relevance: as a bile acid, the deoxycholyl-containing molecules act as detergents that emulsify dietary fats, aiding digestion and absorption. Their composition and concentration are influenced by diet, gut microbiota, and liver function, and they are studied in fields ranging from lipid metabolism to gut microbiome research.