Lipoic Acid

lipoic acid

[lī′pō·ik ′as·əd]

(biochemistry)

C₈H₁₄O₂S₂ A compound which participates in the enzymatic oxidative decarboxylation of α-keto acids in a stage between thiamine pyrophosphate and coenzyme A.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Lipoic Acid

 

6,8-epi-dithio-octanoic acid, a widespread naturally occurring coenzyme, related to enzymes of the class of oxidoreductases. It exists in the form of crystals with melting point 59°-60°C and was first isolated from bull’s liver in 1941 (30 mg of lipoic acid was obtained from 10 tons of liver).

Lipoic acid participates in the transfer of acyl groups (acid radicals) and in biological oxidation reactions (for example, oxidative decarboxylation of pyruvic and ketoglutaric acids for conversion into acetyl-CoA and succinyl-CoA, respectively, with liberation of carbon dioxide). The oxidized form of lipoic acid is transformed into a reduced form, which is then reconverted into the oxidized form upon action of a specific enzyme:

Lipoic acid is the growth factor (vitamin) in certain microorganisms; it exists in composite protein form in the cells of plant and animal tissues.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.