lipoic acid

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lipoic acid:

see coenzymecoenzyme
, any one of a group of relatively small organic molecules required for the catalytic function of certain enzymes. A coenzyme may either be attached by covalent bonds to a particular enzyme or exist freely in solution, but in either case it participates intimately in
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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 It might be outdated or ideologically biased.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.

lipoic acid

[lī′pō·ik ′as·əd]
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.
References in periodicals archive ?
Both animal and human studies demonstrate that R-lipoic acid provides the clinical benefits associated with lipoic acid, but with much greater biological activity.
In one study, R-lipoic acid, the more biologically active form of lipoic acid, was administered to patients with diabetic neuropathy.
(35) R-lipoic acid is relatively unstable and tends to polymerize, whereas the sodium salt, sodium R-lipoate, is much less prone to polymerize and it displays higher plasma concentrations in humans.
Purified R-lipoic acid is highly unstable, degrading with exposure to light, air and temperatures slightly above ambient, affecting both potency and bioavailability.
In addition, animals supplemented with R-lipoic acid age more slowly than they otherwise would.
A dose of pure R-lipoic acid provides twice the active ingredient as a typical R/S-alpha lipoic acid supplement, simply because the whole dose consists of the active "R" molecule.
Nutrient Typical Daily Dose Pyrroloquinoline quinone (PQQ) 10-20 mg CoQ10 100-200 mg R-lipoic acid 300-600 mg Trans-resveratrol 250 mg Acetyl-L-carnitine 1,000-2,000 mg Aging Factor 13: Excitotoxicity
These include quercetin, curcumin, R-lipoic acid, and milk thistle.
Newer precision techniques allow production of a pure R-lipoic acid, which has a much higher potency.
Remember that R-lipoic acid is twice as potent as alpha-lipoic acid.
Furthermore, studies have highlighted the greater potency of a supercharged R-lipoic acid, called R-dihydrolipoic acid, (15,16) which is now also available as a supplement.
(10) The dose of R-lipoic acid to achieve this effect in diabetics would be half this amount, since it is the "R" form of lipoic acid that is biologically active in the body.