SYNTHESIS, SPECTRAL CHARACTERIZATION, AND IN-VITRO ANTIOXIDANT ACTIVITY SCREENING OF SOME NOVEL 2-HYDROXY QUINOLINE DERIVATIVESAbstract
In an attempt of synthesizing some novel and potent antioxidant activity having compounds, here some novel quinoline derivatives are reported. Initially using Vilsemeir-Hack reagent method 7-methyl or 8-methyl substituted 2-cholro-3-formylquinolines (Ia, b) were prepared. Further 7-methyl or 8-methyl substituted 2-hydroxy quinoline-3-carbaldehyde (IIa, b) were synthesized by the reaction of compound (I) on microwave irradiation with 4M HCl, which on further treatment with different substituted hydrazides yielded the novel Schiff bases of quinoline III (a-f). Purity of the synthesized compounds was determined by TLC and melting point. The structure of all newly synthesized compounds was confirmed by spectral studies such as IR, 1H NMR, 13C NMR, and mass spectroscopy. All the synthesized compounds were screened for in-vitro antioxidant activity by free radical scavenging activity by DPPH assays method and ferric ion reduction method using ascorbic acid as the standard drug. Screening results showed that all compounds are exhibiting moderate to good activity. Especially compounds III b, III d, and III f showed significant antioxidant activity.
Pradeep Kumar M. R. * and Hunashal R. D.
Department of Pharmaceutical Chemistry, KLE College of Pharmacy, A Constituent Unit of KLE Academy of Higher Education and Research [KAHER], Hubli, Karnataka, India.
03 January 2021
03 May 2021
28 May 2021
01 December 2021