Exploration of the diketoacid integrase inhibitor chemotype leading to the discovery of the anilide-ketoacids chemotype.

Integrase is one of three enzymes expressed by HIV and represents a validated target for therapy. A previous study of the diketoacid-based chemotype suggested that there are two aryl-binding domains on integrase. In this study, modifications to the indole-based diketoacid chemotype are explored. It is demonstrated that the indole group can be replaced with secondary but not tertiary (e.g., N-methyl) aniline-based amides without sacrificing in vitro inhibitory activity. The difference in activity between the secondary and tertiary amides is most likely due to the opposite conformational preferences of the amide bonds, s-trans for the secondary-amide and s-cis for the tertiary-amide. However, it was found that the conformational preference of the tertiary amide can be reversed by incorporating the amide nitrogen atom into an indoline heterocycle, resulting in very potent integrase inhibitors.