Multistage Molecular Simulations, Design, Synthesis, and Anticonvulsant Evaluation of 2-(Isoindolin-2-yl) Esters of Aromatic Amino Acids Targeting GABAA Receptors via π–π Stacking

Epilepsy remains a widespread neurological disorder, with approximately 30% of patients showing resistance to current antiepileptic therapies. To address this unmet need, a series of 2-(isoindolin-2-yl) esters derived from natural amino acids were designed and evaluated for their potential interaction with the GABAA receptor. Sixteen derivatives were subjected to in silico assessments, including physicochemical and ADMET profiling, virtual screening - ensemble docking, and enhanced sampling molecular dynamics simulations (metadynamics calculations). Among these, compounds derived from the aromatic amino acids, phenylalanine, tyrosine, tryptophan, and histidine exhibited superior predicted affinity, attributed to π–π stacking interactions at the benzodiazepine binding site of the GABAA receptor. Based on computational performance, the tyrosine and tryptophan derivatives were synthesized and further assessed in vivo using the pentylenetetrazole-induced seizure model in zebrafish (Danio rerio). Both compounds significantly reduced seizure severity, with the tryptophan derivative demonstrating equal efficacy to the reference drug diazepam. The results suggest that aromatic amino acid-derived isoindoline esters are promising anticonvulsant candidates and suggest that π–π interactions play a critical role in modulating GABAA receptor binding affinity.