Abstract
Many reports reveal the fact that acylthiamine derivatives, such as BTDS or BTMP produce O-benzoylthiamine (OBT) directly or indirectly as a intermediate compound in the course of the formation of thiamine in the living body. But owing to the fact that OBT changed to thiochrome by the thiochrome reaction using BrCN and NaOH, the differential determination between thiamine and OBT was impossible. As the results of the investigation for the reaction condition with OBT, the author have found a suitable condition which forms benzoylthiochrome and established a differential determination between OBT and thiamine. The condition found by the author is as follows : (1) Benzoylthiochrome is formed from OBT when NH_4OH is used instead of NaOH after the addition of BrCN. (2) Benzoylthiochrome is easily extracted in ethyl acetate, but on the contrary to this thiochrome is hardly extracted in ethyl acetate.
