Design,\nSynthesis, and Biological Evaluation of Darunavir\nAnalogs as HIV‑1 Protease Inhibitors

Darunavir, a frontline treatment for HIV infection, faces\nlimitations\ndue to emerging multidrug resistant (MDR) HIV strains, necessitating\nthe development of analogs with improved activity. In this study,\na combinatorial in silico approach was used to initially design a\nseries of HIV-1 PI analogs with modifications at key sites, P1′\nand P2′, to enhance interactions with HIV-1 PR. Fifteen analogs\nwith promising binding scores were selected for synthesis and evaluated\nfor the HIV-1 PR inhibition activity. The variation of P2′\nsubstitution was found to be effective, as seen in <b>5aa</b> (1.54 nM), <b>5ad</b> (0.71 nM), <b>5ac</b> (0.31 nM), <b>5ae</b> (0.28 nM), and <b>5af</b> (1.12 nM), featuring halogen,\naliphatic, and alkoxy functionalities on the phenyl sulfoxide motif\nexhibited superior inhibition against HIV-1 PR compared to DRV, with\nminimal cytotoxicity observed in Vero and 293T cell lines. Moreover,\ncomputational studies demonstrated the potential of selected analogs\nto inhibit various HIV-1 PR mutations, including I54M and I84V. Further\nstructural dynamics and energetic analyses confirmed the stability\nand binding affinity of promising analogs, particularly <b>5ae</b>, which showed strong interactions with key residues in HIV-1 PR.\nOverall, this study underscores the importance of flexible moieties\nand interaction enhancement at the S2′ subsite of HIV-1 PR\nin developing effective DRV analogs to combat HIV and other global\nhealth issues.