Participation of peroxidase reaction in thiamine catabolism.

The horse-radish peroxidase catalyzes oxidation of thiamine in vitro in presence of hydroperoxide hydrogen (H2O2) and olenic acid (LOOH) (as an emultion) with formation of thiochrome (2,7-dimethyl-8-(oxyetyl-5,6-dihydrothiazolo (2,3-a) pyrimido (4,5-d) pyrimidine, oxodihydrothiochrome (2,7dimethyl-oxo-8-(-2-oxo-ethyl)-5,6,9a, 10-tetrahydrothiazolo (2,3-a) pyrimido (4,5-d) pyrimidine and thiamine disulfide (bis (3-methyl-((1-methyl-4-amino 5 pyrimidine methylformyl) amino 1-2 (oxyethyl)-1-propenyl) disulfide. The transformation of thiamine to thiochrome cause by release of two atoms of hydrogen from NH2-group of pyrimidine ring of molecule of thiamine and occurrence on this place of bond with thiozole ring. The microsomal fraction of rats in vitro in presence of LOOH also activities the oxidation of thiamine to thiochrome. However in these conditions peroxidase reaction is proceeded more slowly.