Deuterated-biphenyl-DAPY derivatives as potent and low-cytotoxicity non-nucleoside reverse transcriptase inhibitors: design, synthesis and anti-HIV-1 evaluation

Non-nucleoside reverse transcriptase inhibitors (NNRTIs) play an important role in AIDS treatment. Diarylpyrimidine derivatives (DAPYs) represent one of the most important classes of NNRTIs. The previously reported ZK-4a showed high cytotoxicity (CC₅₀ = 5.98 μmol·L^-1), significantly limiting its therapeutic potential. To resolve this issue, we adopted a two-pronged strategy: replacing the NH fragment with an O atom and modifying the C-5 position of the pyrimidine core. These modifications enabled the design and synthesis of 27 novel deuterated-biphenyl-DAPY analogues. Fortunately, all deuterated-biphenyl-DAPYs exhibited broad and highly efficient antiviral activity, as well as obviously decreased cytotoxicity (CC₅₀ = 18.02- > 297.27 μmol·L^-1). Among them, compound 8s achieved an EC₅₀ value of 8.88 nmol·L^-1 while showing negligible cytotoxicity (CC₅₀ > 287.68 μmol·L^-1). Compound 8s also displayed exceptional resistance profiles with EC₅₀ values of 7.54 nmol·L^-1 (L100I), 8.57 nmol·L^-1 (K103N), 24.28 nmol·L^-1 (Y181C), 62.71 nmol·L^-1 (Y188L) and 14.38 nmol·L^-1 (E138K). Additionally, the target of deuterated-biphenyl-DAPYs was verified by reverse transcriptase enzyme inhibition assays.