Structural Studies on Bioactive Compounds. 34. Design, Synthesis, and Biological Evaluation of Triazenyl-Substituted Pyrimethamine Inhibitors of <i>Pneumocystis carinii</i> Dihydrofolate Reductase
作者:David C. M. Chan、Charles A. Laughton、Sherry F. Queener、Malcolm F. G. Stevens
DOI:10.1021/jm0108698
日期:2001.8.1
The triazenyl-pyrimethamine derivative 3a (TAB), a potent and selective inhibitor of Pneumocystis carinii DHFR, was selected as the starting point for a lead optimization study. Molecular modeling studies, corroborated by a recent crystal structure determination of the ternary complex of P. carinii DHFR--NADPH bound to TAB, predicted that modifications to the acetoxy residue of the lead inhibitor could
选择了三氮烯基-乙胺嘧啶衍生物3a(TAB)(一种有效的选择性卡氏肺孢子虫DHFR抑制剂)作为前导优化研究的起点。分子建模研究得到了最近对TAB结合的Carinii DHFR-NADPH三元复合物晶体结构测定的证实,预测对铅抑制剂乙酰氧基残基的修饰可利用活性位点附近的结合机会由残基Ile33,Lys37和Leu72结合。预测用给电子基团和吸电子基团取代苄基部分可探测与卡氏疟原虫唯一的氨基酸Phe69的面缘相互作用。新的三氮烯10a-v和12a-f是通过将氨基乙胺的四氟硼酸重氮盐6b与取代的苄胺或苯乙胺偶联而制得的。在新的抗卡氏疟原虫DHFR抑制剂中,最有效的是萘基甲基取代的三氮烯10t(IC(50):0.053 microM),但对大鼠肝脏DHFR的效价更大幅度的升高导致选择性降低(比率为大鼠肝脏DHFR IC(50)/卡氏毕赤酵母DHFR IC(50):5.36)与原始铅结构3a的比率(大鼠肝脏DHFR