Structure-Based Optimization of N‑Substituted Oseltamivir Derivatives as Potent Anti-Influenza A Virus Agents with Significantly Improved Potency against Oseltamivir-Resistant N1-H274Y Variant

Due to the emergence of highly pathogenic and oseltamivir-resistant influenza viruses, there is an urgent need to develop new anti-influenza agents. Herein, five subseries of oseltamivir derivatives were designed and synthesized to improve their activity toward drug-resistant viral strains by further exploiting the 150-cavity in the neuraminidases (NAs). The bioassay results showed that compound 21h exhibited antiviral activities similar to or better than those of oseltamivir carboxylate (OSC) against H5N1, H5N2, H5N6, and H5N8. Besides, 21h was 5- to 86-fold more potent than OSC toward N1, N8, and N1-H274Y mutant NAs in the inhibitory assays. Computational studies provided a plausible rationale for the high potency of 21h against group-1 and N1-H274Y NAs. In addition, 21h demonstrated acceptable oral bioavailability, low acute toxicity, potent antiviral activity in vivo, and high metabolic stability. Overall, the above excellent profiles make 21h a promising drug candidate for the treatment of influenza virus infection.鉴于高致病性且对奥司他韦耐药的流感病毒的出现，开发新型抗流感药物已迫在眉睫。本研究通过靶向神经氨酸酶（neuraminidases, NAs）的150-口袋，设计并合成了五组奥司他韦衍生物，以提升其对耐药流感毒株的活性。生物活性测定结果显示，化合物21h对H5N1、H5N2、H5N6及H5N8亚型流感病毒的抗病毒活性与奥司他韦羧酸（oseltamivir carboxylate, OSC）相当甚至更优。此外，在酶抑制实验中，21h针对N1、N8及N1-H274Y突变型神经氨酸酶的活性是OSC的5至86倍。计算生物学研究为21h对第1组神经氨酸酶及N1-H274Y突变型酶的高活性提供了合理的机制解释。此外，21h还表现出良好的口服生物利用度、较低的急性毒性、显著的体内抗病毒活性以及优异的代谢稳定性。综上，上述优异特性使21h成为一款极具潜力的抗流感病毒感染候选药物。