Abstract
A method of fractional determination of thiamine and O-ethoxycarbonylthiamine (OCET) in urine by the conventional thiochrome method after the separation of each component by thin layer or paper chromatographic technique was described. Using this technique, it was investigated the urinary excretion of thiochrome reaction positive compounds following the administration of ethoxycarbonylthiamine derivatives. After oral administration of O, S-bis (ethoxycarbonyl) thiamine (DCET 400-500mg to men and dogs, about 30% of the dose was recovered in the 24 hours urine as thiochrome reaction positive compounds, in which thiamine and OCET were distributed in a ratio of 98 : 2. In the case of subcutaneous injection of OCET 400mg to dog, 78% of the dose was excreted and the ratio of thiamine and OCET was 96 : 4. When S-ethoxycarbonylthiamine (CET) 500mg was orally administered to dog, urinary output of the thiochrome reaction positive compounds was 38% of the dose. In this case, however, excreted amount of OCET was considerably greater than that of administered DCET or of OCET (thiamine : OCET=82 : 18). These findings suggested that DCET and OCET might be readily matabolized to thiamine, while CET might partly converted into a cyclic intermediate which was further converted into OCET in the course of excretion. This suggestion was supported by the easy conversion of CET into OCET in an aqueous solution incubated at 37℃ and pH 7〜8.
