Synthesis and evaluation of new pyrazoline-thiazole derivatives as monoamine oxidase inhibitors

Abstract

A novel series of 1,3,5-trisubstituted-2-pyrazoline derivatives (4a-4k) was synthesized and their chemical structures characterized by 1H NMR, 13C NMR, and mass spectroscopy. These compounds were evaluated as inhibitors for of type A and type B monoamine oxidase (MAO) enzymes. The most common inhibitors of MAO enzymes used to treat depression and anxiety such as selegiline and moclobemide drugs were used as reference agents. A result of biological evaluation of these compounds revealed compounds 4c, 4d, and 4ı as potent and selective MAO A inhibitors. The most active compound 4ı, which is 2,4-dimethoxy at phenyl ring, showed strong inhibitory activity at MAO A (IC50 of 0.0445 ± 0.0018µM). Furthermore, compounds 4c and 4d showed significant inhibition profile on MAO A with the IC50 values 0.1423 ± 0.0051µM and 0.2148 ± 0.0067µM, respectively