抄録
Thiamine-decomposing activities of various flavonoids and phenols were investigated, and many flavonoids were found to be active; the strongest activities were observed in the substances possessing o-diphenol in the side chain. The compounds, in which 3-hydroxy group in the chromone ring formed glycoside, manifested stronger or weaker activities than the free forms.
Of free phenols studied, pyrocatechol manifested the strongest activity, and many of its derivatives also very strong activities.
This activity not being proportional to the concentration of the substances, a Q50 value was proposed for comparing the activity.
Acceleration by manganese was observed in the decomposition of thiamine by flavonoids and phenols, but the effect was more marked in flavonoids. After heating at 100° for 30 minutes, the effect was as remarkable in phenols as in flavonoids.
