There is a pressing need to improve the efficiency of drug development, and nowhere is that need more clear than in the case of neglected diseases like malaria. The peculiarities of pyrimidine metabolism in Plasmodium species make inhibition of dihydroorotate dehydrogenase (DHODH) an attractive target for antimalarial drug design. By applying a pair of complementary quantitative structure–activity relationships derived for inhibition of a truncated, soluble form of the enzyme from Plasmodium falciparum (s-PfDHODH) to data from a large-scale phenotypic screen against cultured parasites, we were able to identify a class of antimalarial leads that inhibit the enzyme and abolish parasite growth in blood culture. Novel analogs extending that class were designed and synthesized with a goal of improving potency as well as the general pharmacokinetic and toxicological profiles. Their synthesis also represented an opportunity to prospectively validate our in silico property predictions. The seven analogs synthesized exhibited physicochemical properties in good agreement with prediction, and five of them were more active against P. falciparum growing in blood culture than any of the compounds in the published lead series. The particular analogs prepared did not inhibit s-PfDHODH in vitro, but advanced biological assays indicated that other examples from the class did inhibit intact PfDHODH bound to the mitochondrial membrane. The new analogs, however, killed the parasites by acting through some other, unidentified mechanism 24–48 h before PfDHODH inhibition would be expected to do so.

迫切需要提高药物开发的效率，而在疟疾等被忽视的疾病方面，这一需求最为明显。疟原虫中嘧啶代谢的特性使得抑制二氢乳清酸脱氢酶 (DHODH) 成为抗疟药物设计的一个有吸引力的目标。通过应用一对互补的定量构效关系来抑制恶性疟原虫(s- Pf ) 中截短的可溶形式的酶DHODH）从针对培养的寄生虫的大规模表型筛选数据中，我们能够识别出一类抑制酶并消除血液培养中寄生虫生长的抗疟药。设计和合成了扩展该类别的新型类似物，目的是提高效力以及一般药代动力学和毒理学特征。他们的合成也代表了一个机会，可以前瞻性地验证我们的计算机属性预测。所合成的七种类似物的理化性质与预测结果非常吻合，其中五种对血液培养中生长的恶性疟原虫的活性比已发表的先导系列中的任何一种化合物都更有效。制备的特定类似物不抑制 s- PfDHODH 在体外，但先进的生物测定表明，该类的其他例子确实抑制了与线粒体膜结合的完整Pf DHODH。然而，新的类似物在预期Pf DHODH 抑制作用之前 24-48 小时通过其他一些未知的机制杀死寄生虫。