Окислительная трансформация тиамина и его метаболитов под действием нитрита и оксоферрильных форм миоглобина

Interaction of hydrogen peroxide with ferriforms of horse myoglobin and human hemoglobin results in the formation of reactive oxoferryl forms of hemoproteins which oxidize thiamin and its phosphate ethters to thiochrome, thiaminedisulfide and their phosphates respectively. Phenolic compounds and nitrite increase the yield of oxidative products of thiamine and its phosphate ethters under the action of oxoferryl forms of hemoproteins by 1-2 orders. Tyrosine, phenolic compounds, and nitrite can penetrate into heme pocket and reduce oxoferryl form to ferri form. The resulting tyrosyl and phenoxyl radicals oxidize thiamine to thiochrome and thiaminedisulfide. Nitrogen dioxide oxidizes thiamine and thiochrome to produce oxodihydrothiochrome. The role of oxoferryl forms and phenolic compounds in oxidative transformation of thiamine and its derivatives is discussed.