Receptor-based design of novel dihydrofolate reductase inhibitors: benzimidazole and indole derivatives
作者:Kwasi A. Ohemeng、Barbara Roth
DOI:10.1021/jm00108a022
日期:1991.4
Although many thousands of inhibitors of the enzyme dihydrofolate reductase (DHFR) have been synthesized, all of the very active compounds have been 2,4-diaminopyrimidines or very close analogues. This paper describes 2,4-diamino-6-benzylbenzimidazole (3b) and the corresponding indole (4), as well as more complex tri- and tetracyclic derivatives (5 and 6). These were designed on the basis of molecular
尽管已经合成了数千种二氢叶酸还原酶(DHFR)抑制剂,但是所有非常有活性的化合物都是2,4-二氨基嘧啶或非常接近的类似物。本文介绍了2,4-二氨基-6-苄基苯并咪唑(3b)和相应的吲哚(4),以及更复杂的三环和四环衍生物(5和6)。这些是根据对大肠杆菌DHFR的已知X射线结构进行分子建模而设计的,目的是确定是否可以通过将一个氨基取代基置于5元含氮环中来彻底改变二氨基构型,第二个在稠环的邻位,并且仍然显着抑制DHFR。尽管电子角和键角与2,4-二氨基嘧啶的电子角和键角大不相同,pKa值在适当的范围内,并且氢键的距离看来是相当合理的。活性最高的化合物4非常不稳定,仅在10(-4)M范围内具有活性。通过建模研究,二氢茚并咪唑衍生物(如6)对酶显示出很好的拟合性,但活性较低。由于所制得的最具活性的化合物作为细菌DHFR的抑制剂比未取代的5-苄基-2,4-二氨基嘧啶弱2个数量级,因此我们得出这样的环