Abstract
From the finding that the injected TATD into vein binds well with plasma protein, in vitro metabolism of TATD in human blood was investigated by using paper partition chromatography, bioautography and actigraphy. On incubation of TATD with whole blood or blood plasma, It was easily reduced to thiamine and lipoic acid moiety. The latter was further hydrolysed and produced lipoic acid. One part of TATD in blood was found as a bound form of lipoic acid with plasma protein. A free lipoic acid was liberated from the lipoic acid protein complex, which was separated by ethanol or perchloric acid precipitation procedure, with alkaline treatment or thiol compound treatment. The complex formation is supposed to be produced by disulfide exchange reaction of TATD with thiol groups of protein.
