Synthesis, Biological Evaluation and 3D-QSAR of 1,3,5-Trisubstituted-4,5- Dihydro-(1H)-Pyrazole Derivatives as Potent and Highly Selective Monoamine Oxidase A Inhibitors

Title: Synthesis, Biological Evaluation and 3D-QSAR of 1,3,5-Trisubstituted-4,5- Dihydro-(1H)-Pyrazole Derivatives as Potent and Highly Selective Monoamine Oxidase A Inhibitors

Volume: 13 Issue: 12

Author(s): Franco Chimenti, Adriana Bolasco, Fedele Manna, Daniela Secci, Paola Chimenti, Arianna Granese, Olivia Befani, Paola Turini, Roberto Cirilli, Francesco La Torre, Stefano Alcaro, Francesco Ortuso and Thierry Langer

Affiliation:

Keywords: Monoamine oxidase, Reversible monoamine oxidase-A inhibitors, Selective monoamine oxidase-A inhibitors, (1H)-pyrazole derivatives, 3D-QSAR

Abstract: The present report provides a extended study of the chemistry, the inhibitory activity against monoamino oxidases (MAO), and molecular modeling including the 3D-QSAR hypothesis of 1,3,5 - trisubstituted-4,5-dihydro-(1H)-pyrazole derivatives. Four series of about eighty novel pyrazoline derivatives were prepared and investigated for their ability to inhibit the activity of the A and B isoforms of MAO selectively. Most of the new synthesized compounds proved more reversible, potent, and selective inhibitors of MAO-A than of MAO-B, and could be taken into account to develop the search further in this field, knowing that reversible and selective MAO-A inhibitors are used as antidepressant and antianxiety drug. The 30 most active compounds show inhibitory activity on MAO-A in the 8.6 x 10-8 - 9.0 x 10-9M range. Moreover, it should be pointed out that for most of them a high IC50 ≥ 10-9M value is associated with a high A-selectivity (Selectivity Index MAO-B/MAO-A in the 10,000 - 16,250 range). Furthermore, due to the presence of a chiral centre at the C5 position of the pyrazole moiety, we performed the semi-preparative chromatographic enantioseparation of the most potent, selective, and chiral compounds. The separated enantiomers were then submitted to in vitro biological evaluation, and from the results of these experiments it has been possible to point out a difference in inhibiting the two isoforms selectively between the racemic mixture and the single enantiomers. The molecular modeling work was carried out combining the Glide docking approach with CoMFA with the aim to rationalize the structure-activity relationships of each pyrazoline inhibitor toward MAO-A and MAO-B isoforms and to derive a suitable selectivity model.

Cite this article as:

Chimenti Franco, Bolasco Adriana, Manna Fedele, Secci Daniela, Chimenti Paola, Granese Arianna, Befani Olivia, Turini Paola, Cirilli Roberto, Torre La Francesco, Alcaro Stefano, Ortuso Francesco and Langer Thierry, Synthesis, Biological Evaluation and 3D-QSAR of 1,3,5-Trisubstituted-4,5- Dihydro-(1H)-Pyrazole Derivatives as Potent and Highly Selective Monoamine Oxidase A Inhibitors, Current Medicinal Chemistry 2006; 13 (12) . https://dx.doi.org/10.2174/092986706776872907