ABSTRACT

Favipiravir is a broad spectrum antiviral drug that has shown activity against many viruses. Sequel to the recent outbreak of COVID-19, favipiravir is investigated as one of the potential drugs for the treatment of SARS-CoV-2. To augment these efforts, this article reports the rotational isomers, tautomeric states, electronic and spectral properties of favipiravir and its five analogues (Cl, Br, H, CN and CH₃) using quantum chemcial code. The enol forms are more stable and the calculated keto–enol relative energies are in the range of 7.86–10.72 kcal/mol in the gas phase and 1.07–3.46 kcal/mol in the solution phase. The relative stabilization of the more polar keto structure in water environment leads to a significant reduction in keto–enol relative energy by 68% for T705, 71% for T705–Cl and T705–Br, 86% for T1105 (H), 88% for T705–CN and 80% for T705–CH₃. The density functional theory and time-dependent density functional theory with the 6-311++G(d,p) basis set were used in the computation. The theoretical results were successfully compared with available experimental and theoretical data.

摘要

Favipiravir是一种广谱抗病毒药物，已显示出对多种病毒的活性。在最近爆发COVID-19的后遗症中，favipiravir被研究为治疗SARS-CoV-2的潜在药物之一。为了增加这些努力，本文报道了favipiravir及其五个类似物（Cl，Br，H，CN和CH ₃的旋转异构体，互变异构状态，电子和光谱性质））使用量子化学代码。烯醇形式更稳定，气相中酮-烯醇相对能量的计算范围为7.86–10.72 kcal / mol，溶液相为1.07–3.46 kcal / mol。在水环境中，极性更强的酮结构的相对稳定导致酮-烯醇相对能量显着降低，T705，T705-Cl和T705-Br降低71％，T705-Cl和T705-Br降低71％，H1105（H）降低86％对于T705-CN和T705-CH 80％₃。计算中使用了6-311 ++ G（d，p）基组的密度泛函理论和随时间变化的密度泛函理论。理论结果已成功与现有的实验和理论数据进行了比较。