医薬品の生物薬剤学的研究(第7報)o-EthoxybenzamideとN-(β-Hydroxybutyryl)-p-phenetidineの脱エチル化におよぼす尿素誘導体の阻害効果

抄録

The metabolic rates of o-ethoxybenzamide (EBA) and N-(β-hydroxybutyryl)-p-phenetidine (HBP) were investigated when EBA or HBP was incubated with urea derivatives in 9000×g supernatant fraction of the rabbit liver. 1) The inhibitory effect of the deethylation on EBA and HBP was induced by urea as an agent capable of modifying the enzyme structure. Also urea derivatives increased the inhibitory effect as compared with urea. 2) Isovaleryl or isobutyryl substitution of urea increased inhibitory effect of deethylation, and the substituent of Br or allyl present in C₂ of their molecules produced a large inhibitory effect. 3) The important factor of inhibition of deethylation was characterized in the presence of amide in their molecules, as shown by comparing 2-bromo-isovalerylurea and 2-bromo-isovalerylamide. 4) The cyclic ureides were recognized for the inhibition of deethylation, and secobarbital and phenobarbital produced an increase in inhibitory power. The substituent in C₅ of barbiturates was an important factor for the inhibition of deethylation.