Ligand-based design, synthesis and primary in vivo screening of pyrrole derivatives as potential tricyclic anti-inflammatory agents

Arzneimittelforschung. 2006;56(11):753-9. doi: 10.1055/s-0031-1296786.

Abstract

Twelve new compounds were designed as 5-aryl-1H-pyrrole analogs of celecoxib (CAS 169590-42-5) and were synthesized by Paal-Knorr cyclization in three series according to 1H-substitution: derivatives with salicylic acid, pyrazolone or isonicotinamide residues. The average physico-chemical and steric similarity between the prototype and the new analogs (completed with two previously synthesized related products) was assessed to be 82 % and therefore considered as a reliable prerequisite for spatial compatibility and effective binding to the cyclooxygenase (COX) enzymes. The anti-inflammatory effects were determined in acute inflammation model using the carrageenan-induced rat paw edema assay on male Wistar rats (180-200 g) at doses of 10, 20 and 40 mg/kg, i.p. Six of the new products showed higher percent of inhibition (up to 100 %) compared to the highly selective COX-2 inhibitor celecoxib and the nonselective indometacin (CAS 53-86-1) used as reference compounds. Ethyl 1-(1,5-di-methyl-3-oxo-2-phenyl-2,3-dihydro-1H-4-pyrazolyl)-2-methyl-5-phenyl-1H-3-pyrrolecarboxylate (2b), ethyl 5-(4-chlor-ophenyl)-2-methyl-1-[(4-pyridylcarbonyl) amino]-1H-3-pyrrolecarboxylate (3c) and 5-[3-acetyl-2-methyl-5-(4-methylphenyl)-1H-1-pyrrolyl] -2-hydroxybenzoic acid (4b) were pointed out as the most active representatives of each of the three tested sub-series.

MeSH terms

  • Animals
  • Anti-Inflammatory Agents, Non-Steroidal / chemical synthesis*
  • Anti-Inflammatory Agents, Non-Steroidal / pharmacology*
  • Anti-Inflammatory Agents, Non-Steroidal / toxicity
  • Behavior, Animal / drug effects
  • Carrageenan
  • Celecoxib
  • Chromatography, Thin Layer
  • Cyclooxygenase 2 Inhibitors / chemical synthesis*
  • Cyclooxygenase Inhibitors / pharmacology
  • Drug Design
  • Drug Evaluation, Preclinical
  • Edema / chemically induced
  • Edema / drug therapy
  • Edema / pathology
  • Foot / pathology
  • Injections, Intraperitoneal
  • Ligands
  • Magnetic Resonance Spectroscopy
  • Male
  • Mice
  • Pyrazoles / chemical synthesis*
  • Pyrroles / chemical synthesis*
  • Pyrroles / pharmacology*
  • Pyrroles / toxicity
  • Rats
  • Rats, Wistar
  • Spectrometry, Mass, Electrospray Ionization
  • Spectrophotometry, Infrared
  • Structure-Activity Relationship
  • Sulfonamides / chemical synthesis*

Substances

  • Anti-Inflammatory Agents, Non-Steroidal
  • Cyclooxygenase 2 Inhibitors
  • Cyclooxygenase Inhibitors
  • Ligands
  • Pyrazoles
  • Pyrroles
  • Sulfonamides
  • Carrageenan
  • Celecoxib