Synthesis and biological evaluation of 4-hydroxy-5-oxo-2,5-dihydro-1H-pyrrole-3-carboxamides and their zinc(<scp>ii</scp>) complexes as candidate antidiabetic agents
1a–e and ZnSO4 in the presence of LiOH. The aldosereductase (AR) inhibitoryactivity of 1a–e was evaluated to reveal important structural features for 2,5-dihydro-5-oxo-1H-pyrrole derivatives to exhibit high AR inhibitoryactivity. The in vitro insulin–mimetic activity of these complexes was evaluated from 50% inhibitory concentrations (IC50) on free fatty acid (FFA) release from isolated rat adipocytes