Alpha Lipoic Acid is light yellow crystal powder, almost tasteless. Small solubility in water, which is about 1 g/L (20 ° C). Soluble in 10% NaOH solution, soluble in aliphatic solvents. Easily dissolved in ethanol, chloroform, ethyl ether.
Lipoic acid in the form of closed loop disulfide and open chain form reduction, the mixture of two kinds of structure of these two kinds of forms through the oxidation – reduction cycle transformation,
Like biotin, lipoic acid but there often is not free, but with its carboxyl enzyme molecules (such as dihydrogen lipoic acid acetyltransferase) of lysine residues in epsilon – NH2 covalent binding to amide linkage (structure and is similar to the biological cell element). Catalytic formation of amide key enzymes of ATP, sulfur and symplectic amide as reaction product produce sulfur – enzyme coupling, AMP and pyrophosphate. Lipoic acid 1951 l. j. Reed separated into crystal, etc. Because the fatty acid is a kind of sulfur was relegated to a fat-soluble vitamin. But because in the metabolism of the body with the TPP, NAD coenzyme in biochemical reaction, therefore, according to the uniformity of structure and function and someone is to be classified as B vitamins.