Abstract
Interesting selective demethylation of brucine and 4-substituted veratroles, which was found to occur as major metabolism in rabbits, was further investigated by in vitro systems. Using 9000×g. supernatant fraction of rabbit liver homogenate, it was shown that demethylation of brucine and 4-nitroveratrole was catalyzed by so called "liver microsomal drug metabolizing enzyme systems, " and it took place predominantly at the meta-position of the lactam group of brucine and at the para-position of nitro group of 4-nitroveratrole at pH 7.5, coinciding with the in vivo results.1, 2 On the other hand, 4-acetamidoveratrole underwent mostly deacetylation by the same fraction. In addition, demethylation of 4-nitroveratrole studied further by rabbit liver microsomes, and it was found that NADH was even more effective than NADPH as the cofactor if added sufficiently to the incubation mixture.
