Structural design and synthesis of arylalkynyl amide-type peroxisome proliferator-activated receptor gamma (PPAR gamma)-selective antagonists based on the helix12-folding inhibition hypothesis

摘要

Peroxisome proliferator-activated receptor gamma (PPAR gamma) antagonists are candidates for treatment of type 2 diabetes, obesity and osteoporosis. However, few rational design strategies are currently available. Here, we utilized the helix12 (H12)-folding inhibition hypothesis, in combination with our previously determined X-ray crystal structure of PPAR gamma agonist MEKT-21 (6) complexed with the PPAR gamma ligand-binding domain, to design and develop a potent phenylalkynyl amide-type PPAR gamma antagonist 9i, focusing initially on pinpoint structural modification of the propanoic acid moiety of 6. Since 9i retained very weak, but distinct, PPAR gamma agonist activity, we next modified the distal benzene ring of 9i, aiming to delete the residual PPAR gamma agonist activity while retaining the antagonist activity. Introduction of a chlorine atom at the 2-position of the distal benzene ring afforded 9p, which exhibited potent, PPAR gamma-selective full antagonist activity without detectable agonist activity. We found that 9p stabilized the corepressor PPAR gamma complex and suppressed basal PPAR gamma activity. This compound showed anti-adipogenesis activity at the cellular level. This agonist antagonist switching concept based on the H12-folding inhibition hypothesis should also be applicable for designing other classes of PPAR gamma full antagonists. (C) 2014 Elsevier Masson SAS. All rights reserved.