Expanding the Solvent/Protein Region Occupation of the Non-Nucleoside Reverse Transcriptase Inhibitor Binding Pocket for Improved Broad-Spectrum Anti-HIV-1 Efficacy: from Rigid Phenyl-Diarylpyrimidines to Flexible Hydrophilic Piperidine-Diarylpyrimid

Considering the nonideal antiresistance efficacy of our previously reported non-nucleoside reverse transcriptase inhibitor <b>7</b>, a series of novel piperidine-diarylpyrimidine derivatives were designed through expanding solvent/protein region occupation. The representative compound <b>15f</b> proved to be exceptionally potent against Y188L (EC₅₀ = 23 nM), F227L + V106A (EC₅₀ = 15 nM) and RES056 (EC₅₀ = 45 nM), significantly better than <b>7</b>. This analog exerted strong inhibition against wild-type HIV-1 (EC₅₀ = 3 nM) and single mutant strains (L100I, K103N, Y181C, E138 K). Notably, its cytotoxicity and selectivity (CC₅₀ = 18.23 μM, SI = 6537) were 4-fold better than etravirine and rilpivirine. Additionally, it exhibited minimal suppression of CYP isoenzymes and hERG, indicating low potential for drug-drug interactions and cardiotoxicity. No significant acute toxicity and tissue damage at a dose of 2 g/kg were revealed. These findings lay the groundwork for the advancement of <b>15f</b> as a highly potent, safe, and broad-spectrum NNRTI for HIV therapy.