抄録
Metabolic conversion of cyclocarbothiamine into thiamine was studied in vivo as well as in vitro.
1. The compound was easily transformed into thiamine when incubated with rabbit blood.
The supernatant obtained from liver and kidney homogenate of rats also changed cyclocarbothiamine into thiamine. No such conversion occurred with heated supernatant.
2. Manometric measurement of carbon dioxide liberated during the conversion showed that it was produced in an amount equimolar to thiamine.
3. Bioautography with Lactobacillus fermenti revealed that not a trace of cyclocarbothiamine remained unchanged in blood samples taken 30 minutes after oral or intravenous administration to rabbits. Nor was it detected as such in urine.
However, a trace amount of the compound was detected unaltered in threehour urine samples following oral administration of 50mg to human subjects.
4. The following metabolic schema has been established.
Cyclocarbothiamine → Thiamine+CO2
