Cholic acid

Cholic acid is a bile acid, a white crystalline substance that is one of the primary bile acids produced by the liver and stored in the gallbladder. It plays a crucial role in the digestion and absorption of fats and fat-soluble vitamins in the small intestine.

Structure and Properties

Cholic acid is a steroid with a molecular formula of C₂₄H₄₀O₅. It has a molecular weight of 408.57 g/mol. The structure of cholic acid includes a cyclopentanoperhydrophenanthrene ring system with three hydroxyl groups at positions 3, 7, and 12, and a carboxylic acid group at position 24.

Biosynthesis

Cholic acid is synthesized in the liver from cholesterol through a series of enzymatic reactions. The process involves the introduction of hydroxyl groups at specific positions on the steroid nucleus, followed by the oxidation and cleavage of the side chain.

Function

Cholic acid is conjugated with either glycine or taurine to form glycocholic acid and taurocholic acid, respectively. These conjugated bile acids are secreted into the bile and stored in the gallbladder. Upon ingestion of food, bile is released into the duodenum, where bile acids emulsify dietary fats, facilitating their digestion by lipase enzymes.

Clinical Significance

Cholic acid and its derivatives are used in the treatment of certain bile acid synthesis disorders and peroxisomal disorders. It is also used in the management of gallstones and certain types of liver disease.

Metabolism

In the intestine, cholic acid is deconjugated and dehydroxylated by intestinal bacteria to form secondary bile acids, such as deoxycholic acid. These secondary bile acids can be reabsorbed into the bloodstream and returned to the liver via the enterohepatic circulation.

See also

• Bile acid
• Cholesterol
• Liver
• Gallbladder
• Fat digestion