Exploiting the Tolerant Region I of the Non-Nucleoside Reverse Transcriptase Inhibitor (NNRTI) Binding Pocket: Discovery of Potent Diarylpyrimidine-Typed HIV-1 NNRTIs against Wild-Type and E138K Mutant Virus with Significantly Improved Water Solubility and Favorable Safety Profiles

Diarylpyrimidine derivatives (DAPYs) exhibit robust anti-HIV-1 potency, although they have been compromised by E138K variant and severe side-effects and been suffering from poor water solubility. In the present work, hydrophilic morpholine or methylsulfonyl and sulfamide-substituted piperazine/piperidines were introduced into the right wing of DAPYs targeting the solvent-exposed tolerant region I. The anti-HIV-1 activities of 11c (EC50(WT) = 0.0035 mu M, EC50(E138K) = 0.0075 mu M) were the same as and 2-fold better than that of the lead etravirine against the wild-type and E138K mutant HIV-1, respectively, with a relative low cytotoxicity (CC50 >= 173 mu M). Further test showed a significant improvement in the water solubility of 11c. Besides, 11c displayed no significant inhibition on main cytochrome P450 enzymes and exhibited no acute/ subacute toxicities at doses of 2000 mg.kg(-1)/50 mg-kg(-1) in mice. Taken together, we consider that 11c is a promising lead for further structural optimization.