Studies on angiotensin-converting enzyme inhibitors. I. Syntheses and angiotensinconverting enzyme inhibitory activity of 2-(3-mercaptopropionyl)-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid derivatives.
作者:KIMIAKI HAYASHI、YASUHIKO OZAKI、KENICHI NUNAMI、TOMOFUMI UCHIDA、JYOJI KATO、KEIZO KINASHI、NAOTO YONEDA
DOI:10.1248/cpb.31.570
日期:——
(3S)-2-[(2S)-3-Mercapto-2-methylpropionyl]-1, 2, 3, 4-tetrahydroisoquinoline-3-carboxylic acid [(3S), (2S)-6a] was prepared by the reaction of (3S)-1, 2, 3, 4-tetrahydroisoquinoline-3-carboxylic acid tert-butyl ester [(3S)-2a] or benzyl ester [(3S)-2b] with 3-benzoylthio-2-methylpropionyl chloride (3a), followed by fractional crystallization and removal of the protective group. The absolute configuration of (3S), (2S)-6a was confirmed by X-ray diffraction analysis of the thiazepino [4, 3-b] isoquinoline compound (7) derived from 6a. Resolution of 3-benzoylthio-2-methylpropionic acid (8) was completed by using optically active phenylalanine amide as a resolving agent. The other optical isomers of (3S), (2S)-6a were prepared by the reaction of (3S)- or (3R)-2b with optically active 3a. The in vitro ACE inhibitory activity of each isomer of 6a was evaluated. Among them, (3S), (2S)-6a was found to be the most potent inhibitor with an IC50 value of 8.6×10-9M. Compound (3S), (2S)-6a induced a dose-dependent inhibition of the pressor response to angiotensin I after oral administration to normotensive anesthetized rats. Moreover, (3S), (2S)-6a markedly reduced the systolic blood pressure in renal hypertensive rats (RHR) and spontaneously hypertensive rats (SHR). The in vivo ACE inhibitory activity and the hypotensive effects of (3S), (2S)-6a were comparable to those of captopril.
(3S)-2-[(2S)-3-巯基-2-甲基丙酰基]-1, 2, 3, 4-四氢异喹啉-3-羧酸[(3S), (2S)-6a]是通过(3S)-1, 2, 3, 4-四氢异喹啉-3-羧酸叔丁基酯[(3S)-2a]或苄基酯[(3S)-2b]与3-苯甲酰硫-2-甲基丙酰氯(3a)反应制备而成,随后通过分馏结晶去除保护基团。通过对由6a衍生的噻唑烯[4, 3-b]异喹啉化合物(7)进行X射线衍射分析,确认了(3S), (2S)-6a的绝对构型。使用光学活性的苯丙氨酸酰胺作为分解剂完成了3-苯甲酰硫-2-甲基丙酸(8)的分解。通过(3S)-或(3R)-2b与光学活性3a反应制备了(3S), (2S)-6a的其他光学异构体。评估了每种6a异构体的体外ACE抑制活性。其中,(3S), (2S)-6a被发现是最有效的抑制剂,IC50值为8.6×10^-9M。化合物(3S), (2S)-6a在该显混合型麻醉大鼠口服给药后,诱导了对血管紧张素I的加压反应的剂量依赖性抑制。此外,(3S), (2S)-6a显著降低了肾性高血压大鼠(RHR)和自发性高血压大鼠(SHR)的收缩压。(3S), (2S)-6a的体内ACE抑制活性和降压效果与卡托普利相当。