Synthesis and antihypertensive activity of 5-(2-hydroxyphenyl)-1-(3-mercaptopropionyl)-2-pyrrolidinecarboxylic acids.
作者:EISHIN KATO、KOJI YAMAMOTO、YOICHI KAWASHIMA、TOSHIO WATANABE、MASAYUKI OYA、TADASHI ISO、JUNICHI IWAO
DOI:10.1248/cpb.33.4836
日期:——
The (2S, 5R)-(+)- or (2R, 5S)-(-)-thiol (4a or 4b) was synthesized by catalytic hydrogenation of the corresponding (S)-(-)- or (R)-(+)-pyrrolinecarboxylic acid (8a or 8b) resolved with (R)-(-)-1, 2-diphenylethylamine, followed by acylation with 3-(benzoylthio) propionyl chloride and ammonolysis. The thiols were converted into the corresponding O, S-diacetates (16a and 16b), which were transformed into (2R, 5R)-(+)- and (2S, 5S)-(-)-thiols (18a and 18b) via their O, S-diacetates (17a and 17b) by epimerization and then ammonolysis. The stereochemistry of these thiols was elucidated on the basis of synthesis from tert-butoxycarbonyl-L-glutamic acid γ-benzylester (9) and proton nuclear magnetic resonance (1H-NMR) analysis. The thiols were tested for inhibitory activity against angiotensin-converting enzyme in vitro. (2S, 5R)-5-(2-Hydroxyphenyl)-1-(3-mercaptopropionyl)-2-pyrrolidinecarboxylic acid (4a) showed the most potent activity among them.
(2S, 5R)-(+)-或(2R, 5S)-(-)-硫醇(4a或4b)是通过催化氢化相应的(S)-(-)-或(R)-(+)-吡咯啉羧酸(8a或8b),该酸与(R)-(-)-1, 2-二苯基乙胺进行分离后合成的,随后进行酸酐化反应与3-(苯甲硫基)丙酰氯和氨解反应。将这些硫醇转化为相应的O,S-二乙酸酯(16a和16b),再通过其O,S-二乙酸酯(17a和17b)进行表异构化和氨解反应,转化为(2R, 5R)-(+)-和(2S, 5S)-(-)-硫醇(18a和18b)。这些硫醇的立体化学是在以叔丁氧羰基-L-谷氨酸γ-苄酯(9)为基础的合成和质子核磁共振(1H-NMR)分析的基础上阐明的。对这些硫醇进行了体外抗血管紧张素转化酶的抑制活性测试,其中(2S, 5R)-5-(2-羟基苯基)-1-(3-巯基丙酰)-2-吡咯烷羧酸(4a)显示出最强的活性。