Monoamine oxidase inhibitory activity of 3,5-biaryl-4,5-dihydro-1H-pyrazole-l-carboxylate derivatives

Ethyl and phenyl carbamate derivatives of pyrazoline (3a-3h) were synthesized and tested for their MAO inhibitory activity. All the compounds were found to be selective towards MAO-A. Phenyl carbamates (3e-3h) were better than ethyl carbamates (3a-3d) and displayed the best selectivity index. Compound 3f (Ki(MAO-A); 4.96 +/- 0.21 nM) was found to be equally potent as that of standard drug, Moclobemide (Ki(MAO-A); 5.01 +/- 0.13 nM) but with best selectivity index (8.86 x 10-5). Molecular docking studies with R & S conformer of 3f revealed S-enantiomer is better than R-enantiomer as reported earlier by other groups. It is proposed that VdW's radii of the substitution (bulkiness) in ring B determine the potency of phenyl carbamates. (C) 2013 Elsevier Masson SAS. All rights reserved.