Lang Johannes, Koch Jeannette, Dutta Sudip K, Leuthold Mila M, Martina Byron, Klein Christian D
Medicinal Chemistry, Institute of Pharmacy and Molecular Biotechnology IPMB, Heidelberg University, Im Neuenheimer Feld 364, D-69120 Heidelberg, Germany.
Artemis Bioservices, Molengraaffsingel 10, 2629 JD Delft, The Netherlands.
ACS Med Chem Lett. 2025 Jul 15;16(8):1592-1600. doi: 10.1021/acsmedchemlett.5c00219. eCollection 2025 Aug 14.
We present the discovery of pyrazole-3-carboxylic acid derivatives as novel dengue virus (DENV) NS2B-NS3 protease inhibitors. The discovery was triggered by omission of the phenylglycine scaffold of previous lead structures. We established a robust, regioselective synthetic route toward pyrazole-3-carboxylic acid derivatives. Subsequent SAR studies delivered inhibitors with promising activity against the DENV protease in biochemical and reporter gene assays with EC values down to 2.2 μM and antiviral activity against DENV-2 with EC values down to 4.1 μM. Active site binding and target specificity were evaluated by a tryptophan fluorescence quenching assay. We further observed negligible cytotoxicity, no inhibition of the off-targets thrombin and trypsin, and promising early stage pharmacokinetic properties. The 2-aminopyrimidine scaffold was identified as a promising nonbasic replacement of the guanidine moiety. In addition, eliminating the highly hydrophobic phenylglycine moiety of previous compound series provides a crucial increase in drug likeness of this novel flaviviral protease inhibitor class.
我们报道了吡唑-3-羧酸衍生物作为新型登革热病毒（DENV）NS2B-NS3蛋白酶抑制剂的发现。这一发现是由之前先导结构中苯甘氨酸骨架的缺失引发的。我们建立了一条稳健、区域选择性的合成吡唑-3-羧酸衍生物的路线。随后的构效关系研究得到了在生化和报告基因检测中对DENV蛋白酶具有良好活性的抑制剂，其半数有效浓度（EC）值低至2.2 μM，对DENV-2的抗病毒活性的EC值低至4.1 μM。通过色氨酸荧光猝灭试验评估了活性位点结合和靶标特异性。我们还进一步观察到其细胞毒性可忽略不计，对非靶标凝血酶和胰蛋白酶无抑制作用，且具有良好的早期药代动力学性质。2-氨基嘧啶骨架被确定为胍基部分有前景的非碱性替代物。此外，去除先前化合物系列中高度疏水的苯甘氨酸部分，极大地提高了这类新型黄病毒蛋白酶抑制剂的类药性。
