Histamine H2-receptor agonists. Synthesis, in vitro pharmacology, and qualitative structure-activity relationships of substituted 4- and 5-(2-aminoethyl)thiazoles
作者:John C. Eriks、Henk Van der Goot、Geert Jan Sterk、Hendrik Timmerman
DOI:10.1021/jm00095a021
日期:1992.8
series of substituted 4- and 5-(2-aminoethyl)thiazoles was synthesized applying small alkyl substitution variations as reported for histamine. 2-Amino-5-(2-aminoethyl)-4-methylthiazole (Amthamine) proved to be the most potent full histamine H2-receptor agonist on the guinea pig right atrium, being with a pD2 value of 6.21 slightly more potent than histamine. This compound shows no affinity for H1-receptors
众所周知,组胺和双马普利在豚鼠右心房均显示出中等的组胺H 2受体激动活性。对这两种化合物的量子化学计算显示出电子分布和分子静电势(MEP's)的相似性,可以扩展到后者结构的刚性类似物[2-氨基-5-(2-氨基乙基)噻唑]。基于这些结果,利用对组胺报道的小的烷基取代变化合成了一系列取代的4-和5-(2-氨基乙基)噻唑。2-氨基-5-(2-氨基乙基)-4-甲基噻唑(氨基胺)被证明是豚鼠右心房中最有效的全组胺H2受体激动剂,pD2值为6.21,略高于组胺。该化合物对H1受体没有亲和力,在组胺H3受体上是一个完整但微弱的激动剂,pD2值为4.70,因此对组胺H2受体表现出明显的特异性。在5-(2-氨基乙基)噻唑系列中,2-氨基取代基的存在对刺激组胺H2受体不是必需的,从而得出重要的结论,与组胺相反,对于该系列,接受来自受体活性部位的激动剂的噻唑核产生的质子足以刺激组胺H 2-受体。