Detection of reaction products of thiamin degradation by catechol derivatives

To clarify the mechanism of thiamin degradation by catechol derivatives, thiamin and its analogues were incubated with caffeic acid or catechol in 1/15 M phosphate buffer pH 7.4 at 48 degrees C or 50 degrees C. Using thin-layer chromatography and high-performance liquid chromatography, several unknown intermediates of the reaction product, which may have both pyrimidine and catechol moieties, were detected.