抄録
1. Using pure standard preparations it was found that vitamin A acid could be produced from natural vitamin A aldehyde by treating with a dilute alkaline solution according to Cannizzaro's reaction, judging from the findings of spectrophotometry and paper chromatography.
2. Metabolic pathways of β-carotene, vitamin A aldehyde and vitamin A alcohol under anaerobic condition were studied using the intestine of rats, and it was demonstrated that the terminal fission of β-carotene might take place, yielding proteinbound vitamin A aldehyde and β-ionone.
3. Further, the same experiments were performed under aerobic condition, and the fates of β-carotene and vitamin A were studied. The results suggest that at the final step of vitamin A metabolism in the intestine, protein-bound vitamin A aldehyde might be converted to vitamin A alcohol and vitamin A acid.
