Exploring the hydrophobic channel of NNIBP leads to the discovery of novel piperidine-substituted thiophene[3,2-d]pyrimidine derivatives as potent HIV-1 NNRTIs

In this report, a series of novel piperidine-substituted thiophene[3,2-d]pyrimidine derivatives were designed to explore the hydrophobic channel of the non-nucleoside reverse transcriptase inhibitors binding pocket (NNIBP) by incorporating an aromatic moiety to the left wing of the lead K-5a2. The newly synthesized compounds were evaluated for anti-HIV potency in MT-4 cells and inhibitory activity to HIV-1 reverse transcriptase (RT). Most of the synthesized compounds exhibited broad-spectrum activity toward wild-type and a wide range of HIV-1 strains carrying single non-nucleoside reverse transcriptase inhibitors (NNRTI)-resistant mutations. Especially, compound 26 exhibited the most potent activity against wild-type and a panel of single mutations (L100I, K103N, Y181C, Y188L and E138K) with an EC50 ranging from 6.02 to 23.9 nmol/L, which were comparable to those of etravirine (ETR). Moreover, the RT inhibition activity, preliminary structure–activity relationship and molecular docking were also investigated. Furthermore, 26 exhibited favorable pharmacokinetics (PK) profiles and with a bioavailability of 33.8%. Taken together, the results could provide valuable insights for further optimization and compound 26 holds great promise as a potential drug candidate for the treatment of HIV-1 infection.