Studies on the structure-activity relationship of 1,3,3,4-tetra-substituted pyrrolidine embodied CCR5 receptor antagonists. Part 2: Discovery of highly potent anti-HIV agents.

Modification of 1,3,3,4-tetra-substituted pyrrolidine embodied CCR5 receptor antagonists revealed that introducing a fluoro group at the 3-position of the 3-phenyl group to reduce metabolism did not adversely affect the high potency against HIV infection, and that replacing the piperidine ring with a tropane ring could deliver the most potent anti-HIV agents. Stereochemistry of the substituted tropane ring is essential for maintaining the potent anti-HIV activity because only exo-isomers displayed subnanomolar whole cell activity.

Studies on the structure-activity relationship of 1,3,3,4-tetra-substituted pyrrolidine embodied CCR5 receptor antagonists. Part 1: Tuning the N-substituents.

A novel series of CCR5 antagonists has been identified, utilizing the lead, nifeviroc, which were further modified based on bioisosteric principles. Lead optimization was pursued by balancing potential toxicity and potency. Potent analogues with low toxic properties were successfully developed by formation of urea and amide bonds at the nitrogen at position 4- of the pyrrolidine ring.