Medicinal & Biological Chemistry Group (NEQUIMED), São Carlos Institute of Chemistry (IQSC), University of São Paulo (USP), São Carlos, São Paulo, Brazil.
Medicinal & Biological Chemistry Group (NEQUIMED), São Carlos Institute of Chemistry (IQSC), University of São Paulo (USP), São Carlos, São Paulo, Brazil; Programa de Pós-Graduação Interunidades em Bioengenharia - PPGIB-USP, Brazil.
Exp Parasitol. 2020 Dec;219:108032. doi: 10.1016/j.exppara.2020.108032. Epub 2020 Nov 1.
Chagas disease affects several countries around the world with health and sanitation problems. Cysteine proteases are essential for the virulence and replication of the Trypanosoma cruzi, being modulated by dipeptidyl nitriles and derivatives. Here, four dipeptidyl nitrile derivatives were assayed in three T. cruzi morphologies and two strains (Tulahuen and Y) using a set of assays: (i) analysis of the inhibitory activity against cysteine proteases; (ii) determination of the cytotoxic activity and selectivity index; (iii) verification of the inhibition of the trypomastigote invasion in the host cell. These compounds could inhibit the activity of cysteine proteases using the selective substrate Z-FR-MCA for the trypomastigote lysate and extracellular amastigotes. Interestingly, these compounds did not present relevant enzymatic inhibition for the epimastigote lysate. Most of the substances were also cytotoxic and selective against the trypomastigotes and intracellular amastigotes. The best compound of the series (Neq0662) could reduce the enzymatic activity of the cysteine proteases for the trypomastigotes and amastigotes. It was equipotent to the benznidazole drug in the cytotoxic studies using these two parasite forms. Neq0662 was also selective for the parasite, and it inhibited the invasion of the mammalian host cell in all conditions tested at 10 μM. The stereochemistry of the trifluoromethyl group was an important factor for the bioactivity when the two diastereomers (Neq0662 and Neq0663) were compared. All-in-all, these results indicate that these compounds could move further in the drug development stage because of its promising bioactive profile.
恰加斯病影响着世界上许多国家的健康和卫生问题。半胱氨酸蛋白酶对于克氏锥虫的毒力和复制至关重要，并且受到二肽基腈和衍生物的调节。在这里，使用一组测定法在三种 T. cruzi 形态和两种菌株（Tulahuen 和 Y）中测定了四种二肽基腈衍生物：（i）分析对半胱氨酸蛋白酶的抑制活性；（ii）测定细胞毒性活性和选择性指数；（iii）验证对宿主细胞中锥虫的入侵的抑制作用。这些化合物可以使用针对锥虫裂解物和细胞外阿米巴的选择性底物 Z-FR-MCA 抑制半胱氨酸蛋白酶的活性。有趣的是，这些化合物对滋养体裂解物没有表现出相关的酶抑制作用。大多数物质对锥虫和细胞内阿米巴也具有细胞毒性和选择性。该系列中最好的化合物（Neq0662）可以降低锥虫和阿米巴的半胱氨酸蛋白酶的酶活性。它在使用这两种寄生虫形式的细胞毒性研究中与苯并硝唑药物等效。Neq0662对寄生虫也具有选择性，并且在 10 μM 时在所有测试条件下均能抑制哺乳动物宿主细胞的入侵。当比较两个非对映异构体（Neq0662 和 Neq0663）时，三氟甲基的立体化学是生物活性的重要因素。总而言之，这些结果表明，由于其有前途的生物活性谱，这些化合物可能会在药物开发阶段取得进一步进展。
