History
Alpha Lipoic Acid (ALA) was discovered in 1951. It is a sulfur-containing coenzyme, and when it was first isolated and studied, its main function was thought to be in the Krebs Cycle.
In 1988, ALA was discovered to be a potent antioxidant, and is active in both fat- and watersoluble regions of the cell.
Definition
ChEBI: Lipoic acid is a heterocyclic thia fatty acid comprising pentanoic acid with a 1,2-dithiolan-3-yl group at the 5-position. It belongs to a vitamin of the vitaminB complex. Lipoic acid is one of thecoenzymes involved in the decarboxylationof pyruvate by the enzymepyruvate dehydrogenase. Goodsources of lipoic acid include liverand yeast.
Biological Functions
Lipoic acid is a cofactor for five enzymes or classes of enzymes: pyruvate dehydrogenase, a-ketoglutarate dehydrogenase, the glycine cleavage system, branched chain keto acid dehydrogenase, and the alpha-oxo(keto)adipate dehydrogenase. The first two are critical to the citric acid cycle. The GCS regulates glycine concentrations.
Pharmacology
The drug is a cofactor for the pyruvate dehydrogenase complex, ketoglutarate and amino acid hydrogenase complexes. This drug can inhibit lipid oxidation in nerve tissue, prevent glycosylation of proteins, inhibit aldose reductase, and prevent the conversion of glucose or galactose into sorbitol. Animal experiments show that this drug can prevent the development of diabetes, promote the utilization of glucose, and prevent neuropathy caused by hyperglycemia. Lipoic acid is easily reduced to dihydrolipoic acid after entering the human body, both of which can promote the regeneration of vitamin C and vitamin E, and play an antioxidant role. The drug can also increase intracellular glutathione and coenzyme Q10 and chelate certain metal ions.
Side effects
Alpha-lipoic acid is generally considered safe with little to no side effects. In some cases, people may experience mild symptoms like nausea, rashes, or itching.
storage
4°C, protect from light
Structure and conformation
Lipoic acid contains two sulfur atoms (at C6 and C8) connected by a disulfide bond and is thus considered to be oxidized although either sulfur atom can exist in higher oxidation states.The carbon atom at C6 is chiral and the molecule exists as two enantiomers (R)-(+)-lipoic acid (RLA) and (S)-(-)-lipoic acid (SLA) and as a racemic mixture (R/S)-lipoic acid (R/S-LA).
