抄録
α^4-Norpyridoxine (4-NOP) inhibited the growth of Saccharomyces carlsbergensis 4228 in the vitamin B_1- and vitamin B_6- free media. The concentration of 4-NOP required to produce 50% inhibition was 3.3×10^<-8>M. This inhibitory activity was specific for 4-NOP, while 4-deoxypyridoxine and other 4-NOP substitutes were inactive. 4-NOP showed no influence on vitamin B_6 biosynthesis in the cells, different from vitamin B_1. On the contrary, higher vitamin B_6 levels were observed in the cells grown in the presence of 4-NOP, and the ratio of free to esterified vitamin B_6 was much higher. It seemed, therefore, that 4-NOP inhibited the utilization of vitamin B_6 in the cells, presumably at the site of phosphorylation as well as coenzyme action.
