The prokaryotic ATP-dependent ClpP protease, localized in the relict plastid of malaria parasite, represents a potential drug target. In the present study, we utilized in silico structure-based screening and medicinal chemistry approaches to identify a novel pyrimidine series of compounds inhibiting P. falciparum ClpP protease activity and evaluated their antiparasitic activities. Structure-activity relationship indicated that morpholine moiety at C2, an aromatic substitution at N3 and a 4-oxo moiety on the pyrimidine are important for potent inhibition of ClpP enzyme along with antiparasiticidal activity. Compound 33 exhibited potent antiparasitic activity (EC₅₀ 9.0 ± 0.2 μM), a 9-fold improvement over the antiparasitic activity of the hit molecule 6. Treatment of blood stage P. falciparum cultures with compound 33 caused morphological and developmental abnormalities in the parasites; further, compound 33 treatment hindered apicoplast development indicating the targeting of apicoplast.

定位于疟原虫的残质体中的原核ATP依赖性ClpP蛋白酶代表了潜在的药物靶标。在本研究中，我们利用基于计算机结构的筛选和药物化学方法，鉴定了一种新型嘧啶系列化合物，可抑制恶性疟原虫ClpP蛋白酶的活性并评估其抗寄生虫活性。构效关系表明，C2上的吗啉部分，N3上的芳香取代基和嘧啶上的4-氧代部分对于有效抑制ClpP酶及抗寄生虫活性很重要。化合物33表现出强效的抗寄生虫活性（EC₅₀9.0±0.2μM），比命中分子的抗寄生虫活性提高了9倍6。用化合物33处理恶性疟原虫血液培养物会引起寄生虫的形态和发育异常；此外，化合物33的治疗阻碍了蜂胶体的发育，表明了对蜂胶体的靶向。