Marcantonio Enrico, Guazzetti Debora, Coppa Crescenzo, Battistini Lucia, Sartori Andrea, Bugatti Kelly, Provinciael Becky, Curti Claudio, Contini Alessandro, Vermeire Kurt, Zanardi Franca
Department of Food and Drug, University of Parma, Parco Area Delle Scienze 27/A, 43124, Parma, Italy.
Department of Pharmaceutical Sciences, University of Milan, Via Venezian 21, 20133, Milano, Italy.
Eur J Med Chem. 2025 Mar 15;286:117302. doi: 10.1016/j.ejmech.2025.117302. Epub 2025 Jan 21.
The recurrent global exposure to highly challenging viral epidemics, and the still limited spectrum of effective pharmacological options step on the accelerator towards the development of new antiviral medicines. In this work we explored the anti-SARS-CoV-2 potential of a recently launched chiral ring system based on the uracil scaffold fused to carbocycle rings. The asymmetric synthesis of two generations of chiral uracil-based compounds (overall 31 different products), and their in vitro cytotoxicity and antiviral screening against wild-type SARS-CoV-2 in U87.ACE cells allowed us to identify seven non-cytotoxic enantioenriched derivatives exhibiting in vitro EC in the 6-37 μM range. Among these compounds, bicyclic uracil 10 showed the best antiviral potency against SARS-CoV-2 (EC 20A.EU2 = 7.41 μM and EC Omicron = 19.4 μM), combined with a favourable selectivity index. Additionally, it exhibited single-digit micromolar inhibition of the isolated SARS-CoV-2 RNA-dependent RNA polymerase (IC = 2.1 μM). Starting from a reported cryo-EM structure of RdRp, docking and molecular dynamics simulations were performed to rationalize possible binding modes of the active compounds. Interestingly, no inhibition of viral replication in cells was observed against a wide spectrum of human viruses, while some derivatives, and especially hit compound 10, exhibited specific low micromolar antiviral effect against β-coronavirus OC43. Collectively, these data indicate that this novel uracil-based ring system represents a valid starting point for further development of a new class of RdRp inhibitors to treat SARS-CoV-2 and, potentially, other β-coronavirus infections.
全球反复面临极具挑战性的病毒流行疫情，且有效的药物选择范围仍然有限，这加速了新型抗病毒药物的研发。在这项工作中，我们探索了一种最近推出的基于与碳环稠合的尿嘧啶骨架的手性环系统对严重急性呼吸综合征冠状病毒2（SARS-CoV-2）的抗病毒潜力。两代手性尿嘧啶基化合物（共31种不同产物）的不对称合成，以及它们在U87.ACE细胞中对野生型SARS-CoV-2的体外细胞毒性和抗病毒筛选，使我们能够鉴定出七种非细胞毒性的对映体富集衍生物，其体外半数有效浓度（EC）在6 - 37 μM范围内。在这些化合物中，双环尿嘧啶10对SARS-CoV-2表现出最佳的抗病毒效力（EC 20A.EU2 = 7.41 μM，EC奥密克戎 = 19.4 μM），同时具有良好的选择性指数。此外，它对分离的SARS-CoV-2 RNA依赖性RNA聚合酶表现出个位数微摩尔级别的抑制作用（IC = 2.1 μM）。从已报道的RNA依赖性RNA聚合酶（RdRp）的冷冻电镜结构出发，进行了对接和分子动力学模拟，以阐明活性化合物可能的结合模式。有趣的是，未观察到这些化合物对多种人类病毒在细胞中的病毒复制有抑制作用，而一些衍生物，特别是命中化合物10，对β冠状病毒OC43表现出特定的低微摩尔级抗病毒作用。总体而言，这些数据表明，这种新型的基于尿嘧啶的环系统是进一步开发用于治疗SARS-CoV-2以及潜在地治疗其他β冠状病毒感染的新型RdRp抑制剂的有效起点。
