Discovery and Structure-Activity Relationships of Novel Template, Truncated 1′-Homologated Adenosine Derivatives as Pure Dual PPARγ/δModulators

Following our report that A3 adenosine receptor (AR) antagonist 1 exhibited a polypharmacological profile as a dual modulator of peroxisome proliferator-activated receptor (PPAR)γ/δ, we discovered a new template, 1′-homologated adenosine analogues 4a-4t, as dual PPARγ/δmodulators without AR binding. Removal of binding affinity to A3AR was achieved by 1′-homologation, and PPARγ/δdual modulation was derived from the structural similarity between the target nucleosides and PPAR modulator drug, rosiglitazone. All the final nucleosides were devoid of AR-binding affinity and exhibited high binding affinities to PPARγ/δbut lacked PPARα binding. 2-Cl derivatives exhibited dual receptor-binding affinity to PPARγ/δ, which was absent for the corresponding 2-H derivatives. 2-Propynyl substitution prevented PPARδ-binding affinity but preserved PPARγaffinity, indicating that the C2 position defines a pharmacophore for selective PPARγligand designs. PPARγ/δdual modulators functioning as both PPARγpartial agonists and PPARδantagonists promoted adiponectin production, suggesting their therapeutic potential against hypoadiponectinemia-associated cancer and metabolic diseases.