Identification of 2-(4-N,N-Dimethylaminophenyl)-5-methyl-1-phenethyl-1H-benzimidazole targeting HIV-1 CA capsid protein and inhibiting HIV-1 replication in cellulo.

The capsid (CA) subunit of the HIV-1 Gag polyprotein is involved in several steps of the viral cycle, from the assembly of new viral particles to the protection of the viral genome until it enters into the nucleus of newly infected cells. As such, it represents an interesting therapeutic target to tackle HIV infection. In this study, we screened hundreds of compounds with a low cost of synthesis for their ability to interfere with Gag assembly in vitro. Representatives of the most promising families of compounds were then tested for their ability to inhibit HIV-1 replication in cellulo. From these molecules, a hit compound from the benzimidazole family with high metabolic stability and low toxicity, 2-(4-N,N-dimethylaminophenyl)-5-methyl-1-phenethyl-1H-benzimidazole (696), appeared to block HIV-1 replication with an IC50 of 3 µM. Quantitative PCR experiments demonstrated that 696 does not block HIV-1 infection before the end of reverse transcription, and molecular docking confirmed that 696 is likely to bind at the interface between two monomers of CA and interfere with capsid oligomerization. Altogether, 696 represents a promising lead molecule for the development of a new series of HIV-1 inhibitors.