Discovery of novel fused-heterocycle-bearing diarypyrimidine derivatives as HIV-1 potent NNRTIs targeting tolerant region I for enhanced antiviral activity and resistance profile

As an important part of anti-AIDS therapy, HIV-1 non-nucleoside reverse transcriptase inhibitors are plagued by resistance and toxicity issues. Taking our reported XJ-18b1 as lead compound, we designed a series of novel diarypyrimidine derivatives by employing a scaffold hopping strategy to discover potent NNRTIs with improved anti-resistance properties and drug-like profiles. The most active compound 3k exhibited prominent inhibitory activity against wild-type HIV-1 (EC₅₀ = 0.0019 μM) and common mutant strains including K103 N (EC₅₀ = 0.0019 μM), L100I (EC₅₀ = 0.0087 μM), E138K (EC₅₀ = 0.011 μM), along with low cytotoxicity and high selectivity index (CC₅₀ = 21.95 μM, SI = 11478). Additionally, compound 3k demonstrated antiviral activity against HIV-2 with EC₅₀ value of 6.14 μM. The enzyme-linked immunosorbent assay validated that 3k could significantly inhibit the activity of HIV-1 reverse transcriptase (IC₅₀ = 0.025 μM). Furthermore, molecular dynamics simulation studies were performed to illustrate the potential binding mode and binding free energy of the RT-3k complex, and in silico prediction revealed that 3k possessed favorable drug-like profiles. Collectively, 3k proved to be a promising lead compound for further optimization to obtain anti-HIV drug candidates.