Synthesis and Biological Evaluation of Some Novel Quinoline based Chalcones as Potent Antimalarial, Anti-inflammatory, Antioxidant and Antidiabetic Agents

Abstract

The objective of the present study was to synthesize a series of some novel quinoline based methoxy substituted chalcones and to evaluate their in vitro antimalarial, anti-inflammatory, antioxidant and antidiabetic activitites. The quinoline based chalcones was synthesized by condensation of 2-chloro-3-formyl qunoline with various methoxy substituted acetophenone in presence of NaOH. The Claisen-Schmidt condensation gave high yield of quinoline based chalcones. Synthesis of 2-chloro-3-formyl quinoline was carried out by Vilsmeir-Haack reaction on acetanilide and 4-methoxy acetanilide which on cyclization along with formylation give corresponding 2-chloro-3-formyl quinoline. The synthesized compounds were screened for in vitro antimalarial, anti-inflammatory, antioxiadant and antidiabetic activities. The structures of the synthesized compounds were characterized by infrared, 1H NMR and 13C NMR spectroscopy. Compounds 1f and 1h showed highest antimalarial activity even more than standard chloroquine diphosphate. Compound 1a showed excellent activity whereas 1c and 1d showed potent anti-inflammatory activity as compared to standard diclofenac. On the other hand, compounds 1a and 1g showed excellent antioxidant activity for 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical while compound 1a showed highest inhibition of nitic oxide free radical (NO•) and compound 1h showed highest inhibition for super oxide radical (SOR) as well as highest antidiabetic activity as compared to standard acarbose. All quinolne based chalcones were synthesized in good yields and showed potential biological activities hence they may be helpful for the designing of new drugs.