A simple method of transforming classical antihistaminics into nonsedative antiallergic agents with strong effects in rat models is described. Various [4-(diphenylmethoxy)piperidino]- (series A), [4-(diphenylmethyl)piperazinyl]- (series B) and [4-(diphenylmethylene)piperidino]alkanoic acid derivatives (series C) were synthesized and examined for antiallergic activities and effects on the central nervous system (CNS), in comparison with the corresponding N-methyl derivatives (1a-c). N-Alkylcarboxylic acids (5a-c) showed stronger ingibitory effects on compound 48/80-induced lethality in rats than the corresponding N-methyl derivatives (1a-c). In particular, N-alkylcarboxylic acids (5a) in series A exhibited approximately 100-fold stronger inhibitory effects than 1a, and were the least effective in prolonging the sleeping time on hexobarbital-induced anesthesia in mice in all series. As a result of chemical modification in series A, it was found that introduction of a methyl group at the para-position on one benzene ring in the (diphenylmethoxy)piperidine system effectively reduced CNS side-effects without reducing antiallergic activityl. (+)-3-[4-[(4-Methylphenyl)phenylmethoxy]piperidino]propionic acid ((+)-5l), an optically active isomer of 5l, exhibited a stronger antiallergic effect (ED50=0.17mg/kg, p.o.) than ketotifen and terfenadine in the 48h homologous passive cutaneous anaphylaxis (PCA) test, and moreover exhibited no CNS side-effects, such as prolongation of the sleeping time on hexobarbital-induced anesthesia, at an oral dose of 30mg/kg. Compound (+)-5l was thus proved to be a promising candidate as a nonsedative antiallergic agent.
描述了一种将经典
抗组胺药物转化为具有强效的非镇静抗过敏剂的简单方法,该方法在大鼠模型中进行了测试。合成并检查了多种[4-(二
苯基甲氧基)
哌啶](A系列)、[4-(二苯基甲基)
哌嗪](B系列)和[4-(二苯基亚甲基)
哌啶]酸衍
生物(C系列)的抗过敏活性及对中枢神经系统(CNS)的影响,与相应的N-甲基衍
生物(1a-c)进行了比较。N-烷基
羧酸(5a-c)对化合物48/80诱导的大鼠致死作用显示出比相应的N-甲基衍
生物(1a-c)更强的抑制效果。特别是A系列中的N-烷基
羧酸(5a)表现出大约100倍于1a的更强抑制效果,并且在所有系列中,对于延长
戊巴比妥诱导的麻醉睡眠时间的效果最差。通过对A系列进行
化学修饰发现,在(二
苯基甲氧基)
哌啶体系中,在一个苯环的对位引入甲基可以有效降低CNS副作用,而不减少抗过敏活性。(+) -3-[4-[(4-甲基苯基)
苯基甲氧基]
哌啶]
丙酸((+) -5l),是5l的光学活性异构体,在48小时同源被动皮肤过敏反应(PCA)测试中展现出比
酮替芬和
特非那定更强的抗过敏效果(ED50 = 0.17 mg/kg,口服),而且在30 mg/kg的口服剂量下没有表现出延长
戊巴比妥诱导的麻醉睡眠时间等CNS副作用。因此,化合物(+) -5l被证明是一个有前景的非镇静抗过敏剂候选药物。