Based on crystal structures of Trypanosoma brucei methionyl-tRNA synthetase (TbMetRS) bound to inhibitors, we designed, synthesized, and evaluated two series of novel TbMetRS inhibitors targeting this parasite enzyme. One series has a 1,3-dihydro-imidazol-2-one containing linker, the other has a rigid fused aromatic ring in the linker. For both series of compounds, potent inhibition of parasite growth was achieved with EC₅₀ < 10 nM and most compounds exhibited low general toxicity to mammalian cells with CC₅₀s > 20 000 nM. Selectivity over human mitochondrial methionyl tRNA synthetase was also evaluated, using a cell-based mitochondrial protein synthesis assay, and selectivity in a range of 20–200-fold was achieved. The inhibitors exhibited poor permeability across the blood brain barrier, necessitating future efforts to optimize the compounds for use in late stage human African trypanosomiasis.

中文翻译：

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具有结构指导的选择性蛋氨酸-tRNA合成酶抑制剂对布鲁氏锥虫的有效活性的发现

基于与抑制剂结合的布鲁氏锥虫蛋氨酸-tRNA合成酶（Tb MetRS）的晶体结构，我们设计，合成和评估了针对该寄生虫酶的两种新型Tb MetRS抑制剂。一个系列具有包含1,3-二氢-咪唑-2-的接头，另一个系列在接头中具有刚性的稠合芳环。对于这两种化合物，当EC ₅₀ <10 nM时，都可以有效抑制寄生虫的生长，并且大多数化合物对CC _50的哺乳动物细胞均表现出较低的一般毒性。s> 20 000 nM。还使用基于细胞的线粒体蛋白质合成测定法评估了对人类线粒体甲硫氨酸tRNA合成酶的选择性，并实现了20-200倍的选择性。这些抑制剂在血脑屏障上的渗透性较差，因此有必要进一步努力优化用于晚期人类非洲锥虫病的化合物。