Stereoselective Hydrolysis of O-Acetyl Propranolol as Prodrug in Rat Tissue Homogenates
作者:Koichi Takahashi、Satoko Tamagawa、Jun Haginaka、Hiroyuki Yasuda、Toyoshi Katagi、Nobuyasu Mlzuno
DOI:10.1002/jps.2600810307
日期:1992.3
characteristics of the hydrolysis of O-acetyl propranolol were studied using phosphate buffer (pH 7.4), rat plasma, and rat tissue homogenates. In the phosphate buffer, no difference was observed in the hydrolysis rate between the esters of (R)- and (S)-propranolol. In rat plasma and tissue homogenates, hydrolysis of the ester was both accelerated and stereoselective. Hydrolysis of O-acetyl (R)-propranolol
使用磷酸盐缓冲液(pH 7.4),大鼠血浆和大鼠组织匀浆研究了O-乙酰基普萘洛尔水解的立体化学特征。在磷酸盐缓冲液中,在(R)-和(S)-普萘洛尔的酯之间的水解速率没有观察到差异。在大鼠血浆和组织匀浆中,酯的水解既加速又立体选择性。在大鼠血浆中,O-乙酰基(R)-普萘洛尔的水解速度比(S)-异构体的水解快五倍。但是,在肝脏和肠匀浆中,(S)-异构体的水解速度比(R)-异构体快。在实验条件下未观察到(R)-和(S)-异构体之间的相互转化。外消旋的O-乙酰基普萘洛尔也观察到相同的立体选择性水解。然而,观察到的水解速率常数低于纯异构体。这些结果表明,O-乙酰基普萘洛尔的酶促水解是立体选择性发生的,血浆酶的选择性不同于肝和肠酶。