ビタミンB_2の生合成に必須の4炭素源について

概要

論文の詳細を見る
The biosynthetic pathways of riboflavin were shortly reviewed. The involvement of 4-carbon compound essential for formation of the o-xylene ring in riboflavin molecule was studied. Stimulation of riboflavin synthesis with ethanol in Ashbya gossypii indicated a clearcut precursor-product relationship between maximum accumulation of riboflavin and diacetyl plus acetoin during the resting cell incubation. The tracer experiments with [U-^<14>C]-glucose and -diacetyl in Eremothecium ashbyii provided evidence that the 4-carbon unit is not supplied with the ribityl fragment of 4-ribitylamino-5-amino-2,6-dihydroxypyrimidine. but with diacetyl. Furthermore, the experiments with a N-189-10A strain of the several riboflavin deficient mutants of yeast (Saccharomyces cerevisiae) which lacks GTP cyclohydrolase showed a specified relationship of diacetyl to riboflavin formation. These results indicate, thus, a strong possibility that diacetyl is the 4-carbon compound essential for formation of riboflavin although it remains to be solved whether its involvement in riboflavin formation is enzymatic or non-enzymatic.
日本ビタミン学会の論文
1988-03-25