Parvin Kumar

3-Aryl-1-phenyl-1H-pyrazole derivatives as new multitarget directed ligands for the treatment of Alzheimer's disease, with acetylcholinesterase and monoamine oxidase inhibitory properties

A series of 3-aryl-1-phenyl-1H-pyrazole derivatives was synthesized in good yield and assayed in vitro as inhibitors of the mice acetylcholinesterase (AChE) and two goat liver monoamine oxidase (MAO) isoforms, MAO-A and MAO-B. Most of the compounds demonstrated a good AChE and selective MAO-B inhibitory activities in the nanomolar or low micromolar range. N-((3-(4-chlorophenyl)-1-phenyl-1H-pyrazole-4-yl) methylene) benzenamine (3e, pIC50 = 4.2) and N-((4-fluorophenyl)-1-phenyl-1H-pyrazole-4-yl) methylene) methanamine (3f, pIC50 = 3.47) were the most potent AChE and highly selective MAO-B inhibitors respectively. Structure activity relationships showed that chloro derivatives were more effective AChE inhibitors as compared to fluoro derivatives while reverse trend was observed in MAO-B inhibitory activity. With the aid of modeling studies, potential binding orientations as well as interactions of the compounds in the AChE and MAO-B active sites were examined.

Iodobenzene diacetate (IBD) catalyzed an quick oxidative aromatization of Hantzsch-1,4-dihydropyridines to pyridines under ultrasonic irradiation.

This project was undertaken to demonstrate the potential of iodobenzene diacetate for the oxidative aromatization of Hantzch-1,4-dihydropyridines under ultrasonic irradiation. All reactions were carried out under ultrasonic irradiation and results were compared with traditional method. Sonochemical switching was observed in case of oxidative aromatization of 4-n-alkyl substituted 1,4-DHP. Without sonication, dealkylation occurred in case of n-alkyl substituted 1,4-DHP (ionic mechanism) but under ultrasonic irradiation, n-alkyl group was not expelled (radical mechanism). However, secondary alkyl (isopropyl) and benzyl group were expelled under both conditions.