title: Rhodanine derivatives as novel peroxisome proliferator-activated receptor gamma agonists.
abstract: OBJECTIVE
  To characterize the in vitro bioactivities of rhodanine derivatives as novel peroxisome proliferator-activated receptor (PPAR) gamma modulators, based on a hit (SH00012671) identified during high-throughput screening (HTS) of a diverse synthetic compound library, and to preliminarily elucidate the structure-activity relationship of this class of PPARgamma agonists.
  
  
  METHODS
  Full-length PPARgamma and retinoid X receptor alpha (RXRalpha), biotinylated PPAR response element (PPRE), [3H]BRL49653 (rosiglitazone), and streptavidin-coated FlashPlate or microbeads were used to measure the receptor-binding properties of various compounds based on the scintillation proximity assay (SPA) technology. A recombinant PPRE vector was transiently cotransfected with PPARgamma and RXRalpha plasmids into the African green monkey kidney (CV-1) cells, and the effects of BRL49653 and test compounds on transcription mediated by PPARgamma were determined by examining luciferase (reporter) responses. 3T3-L1 cells were employed to determine whether the compounds facilitated adipogenesis upon PPARgamma activation.
  
  
  RESULTS
  Of the 16,000 samples screened with the SPA method, only 1 compound (SH00012671) displayed a similar binding affinity (Ki=186.7 nmol/L) to PPARgamma as BRL49653, but it was inactive in the cell-based assays. A series of rhodanine derivatives were synthesized based on the core structure of SH00012671 and 8 of them showed agonist activities in both cotransfection and pre-adipocyte differentiation assays. To reduce intrinsic cytotoxicities, the sulphur on the rhodanine was changed to oxygen. This alteration led to a decrease in receptor-binding affinities while modified analogues generally maintained agonist efficacies in the cell-based assays. Of the analogues studied, compound 31 exhibited about 70% the efficacy exerted by BRL49653 in both cotransfection and pre-adipocyte differentiation assays.
  
  
  CONCLUSIONS
  Through minor chemical modifications on the core structure of the initial HTS hit, SH00012671 was transformed to possess both molecular (PPARgamma binding) and cellular (adipogenesis) activities. The rhodanine derivatives reported here may represent a new scaffold in further understanding the molecular mechanism of agonism at PPARgamma.
authors.affiliation: The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Liu
authors.forename: Yue-yun
authors.initials: YY
authors.lastname: Zhang
authors.forename: Hui-li
authors.initials: HL
authors.lastname: Lu
authors.forename: Qun-yi
authors.initials: QY
authors.lastname: Li
authors.forename: Cai-hong
authors.initials: CH
authors.lastname: Zhou
authors.forename: Ming-wei
authors.initials: MW
authors.lastname: Wang
mesh_terms: D000818:Animals; D002460:Cell Line; D051379:Mice; D047495:PPAR gamma / Q000819:agonists*; D012235:Rhodamines / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D047495:PPAR gamma; D012235:Rhodamines