Synthesis and antiviral property of allophenylnorstatine-based HIV protease inhibitors incorporating d-cysteine derivatives as P2/P3 moieties

We designed several HIV protease inhibitors with various d-cysteine derivatives as P2/P3 moieties based on the structure of clinical drug candidate, KNI-764. Herein, we report their synthesis, HIV protease inhibitory activity, HIV IIIB cell inhibitory activity, cellular toxicity, and inhibitory activity against drug-resistant HIV strains. KNI-1931 showed distinct selectivity against HIV proteases and high potency against drug-resistant strains, surpassing those of Ritonavir and Nelfinavir.