Synthesis of some novel 3- (4-ethoxyphenyl) -5- (4-substituted) -4,5-dihydro-1H-pyrazole derivatives as potent antioxidant agents

Abstract

Pyrazolines are the most useful heterocyclic moiety in Pharmaceutical and Chemical ields and as the most potential molecules for the design of new chemical entities. Nitrogen-containing heterocyclic compounds, pyrazolines and their derivatives showed a variety of pharmacological activities, including antioxidant properties. In the present study, eleven novel ethoxylated pyrazoline derivatives were synthesized by condensing chalcones with electron releasing ethoxy group at one end and different electron-donating, electronwithdrawing groups in another end with hydrazine hydrate and alcohol. The compounds synthesized were structural elucidated by their spectroscopic studies. All the compounds synthesized were evaluated for their in vitro antioxidant potential by 2,2'-diphenyl-1-picrylhydrazyl (DPPH) and hydrogen peroxide free radical scavenging assay methods. Some of these molecules possess moderate to good antioxidant activity when compared to standard ascorbic acid. The compound with methoxy group (EH2) exhibits potent antioxidant activity with IC 50 value of 9.02 and 9.44µg/ml in DPPH and hydrogen peroxide assay methods respectively and the compound with hydroxy group (EH9) also showed potent antioxidant activity with IC 50 value of 12.41 and 14.56µg/ml in DPPH and hydrogen peroxide free radical scavenging assay methods respectively when compared to standard. The compounds containing electron-donating substituents were found to be good antioxidants when compared to standard ascorbic acid.

In Vitro Antiplasmodial and Cytotoxic Activities of Compounds from the Roots of Eriosema montanum Baker f. (Fabaceae)

“…However, this effect decreased when the methoxy group is on both rings. In addition, it was reported in the literature that the presence of a methoxy group or any electron donating group enhances other biological activities of chalcones and flavonoids [ 21 , 22 , 23 ]. Though isoflavonoids seem to have an important share of the antiplasmodial activity of the plant, eucomic acid was the most active among all the tested compounds ( Table 1 ).…”

Rational Design and Synthesis of Isatin‐Chalcone Hybrids Integrated with 1H‐1,2,3‐Triazole: Anti‐Proliferative Profiling and Molecular Docking Insights

“…[11] At the moment, both naturally occurring and synthetic chalcones gained increased attention towards medicinal chemistry research owing to their widespread array of biological properties. The class of molecules are found to possess antibacterial, [12][13][14] analgesic, [15,16] anticancer, [17,18] antiinflammatory, [19][20][21] anticholinergic, [22] and antimalarial activities. [23] Chalcones, boast a simple and unique structure, and robust anti-proliferative potential, which have captured the attention of chemists in the quest to discover improved biologically active frameworks.…”

Photoinduced, Metal-Free Hydroacylation of Aromatic Alkynes for Synthesis of α,β-Unsaturated Ketones via C(sp3)–H Functionalization

“…In synthetic organic chemistry, α,β-unsaturated ketones have been widely used as adaptable substances, such as vital substrates for Michael addition, Diels–Alder, Morita–Baylis–Hillman, and epoxidation reactions. α,β-Unsaturated ketones containing natural and synthetic chalcones have been the subject of extensive research in medicinal chemistry in the twenty-first century as they have a wide range of biological potential that is fascinating and useful in therapeutic development, such as anti-inflammatory, antibiotic, antioxidant, anticancer, antiplatelet, antidiabetic, aldose reductase inhibition, acetylcholinesterase inhibition, and immunomodulatory and as non-purine xanthine oxidase inhibitors . Several chalcone-based medications like metochalcone (Scheme c), a choleretic drug, are used.…”