Pyrazoline based MAO inhibitors: Synthesis, biological evaluation and SAR studies

Twenty-two pyrazoline derivatives were synthesized and tested for their human MAO (hMAO) inhibitory activity. Twelve molecules with unsubstituted ring A and substituted ring C (5–16) were found to be potent inhibitors of hMAO-A isoform with SIMAO-A in the order 103 and 104. Ten molecules with unsubstituted ring A and without ring C (21–30), in which eight molecules (21, 23–26, and 28–30) were selective for hMAO-A, one for hMAO-B (22) and the other one non-selective (27). Presence of ring C increases potency as well as SI towards hMAO-A; however its absence decreases both potency and SI towards hMAO-A and hMAO-B.

Graphical abstractPyrazoline derivatives with unsubstituted ring A and substituted ring C (5–16) were found to be potent inhibitors of MAO-A isoform with SIMAO-A in the order of 103 and 104.Figure optionsDownload full-size imageDownload as PowerPoint slide