Thioctic acid requirement

Langry KC, Ratio TV, Rudd RE, McElfresh MW. 2005. The AFM measured force required to rupture the dithiolate linkage of thioctic acid to gold is less than the rupture force of a simple gold-alkyl thiolate bond. Langmuir 21 12064-12067. 

The isolation of lipoic acid in 1951 followed an earlier discovery that the ciliate protozoan Tetrahymena geleii required an unknown factor for growth. In independent experiments acetic acid was observed to promote rapid growth of Lactobacillus casei, but it could be replaced by an unknown "acetate replacing factor." Another lactic acid bacterium Streptococcus faecalis was unable to oxidize pyruvate without addition of "pyruvate oxidation factor." By 1949, all three unknown substances were recognized as identical.291 2913 After working up the equivalent of 10 tons of water-soluble residue from liver, Lester Reed and his collaborators isolated 30 mg of a fat-soluble acidic material which was named lipoic acid (or 6-thioctic acid).292 294... 

No special precautions seem to be required if thioctic acid is given to patients taking acarbose, metformin or glibenciamide. 

It is found in vegetable tissues and in bacteria but not in animal tissues. Nevertheless, in animals and in certain micro-organisms, there is a system for the oxidative decarboxylation of pyruvic acid which requires a series of cofactors (CoA, DPN, TPP and thioctic acid) the initial reaction is as follows ... 

The basic B vitamins are regularly required by all animals. Exceptions are rare for instance, niacin is not required by mammals (in the presence of adequate tryptophan) nor biotin by Tetrahymena, The need for thiamine, riboflavin, pyridoxine (or derivatives), pantothen, and folic acid appears to be universal throughout the animal kingdom. Rather rare and specialized requirements are encountered, such as cholesterol for certain trichomonad flagellates and insects hemin for trypanosomids and at least one bloodsucking insect carnitine for two species of beetles thioctic acid for ciliates and purines and pyrimidines for ciliates. 

Lipoic Acid thioctic acid) seems to be required only by microorganisms. 

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