Coumarins as Potential Antioxidant Agents Complemented with Suggested Mechanisms and Approved by Molecular Modeling Studies

Abstract

Syntheses of coumarins, which are a structurally interesting antioxidant activity, was done in this article. The modification of 7-hydroxycoumarin by different reaction steps was done to yield target compounds. Molecular structures were characterized by different spectroscopical techniques (Fourier transformation infrared and nuclear magnetic resonance). Antioxidant activities were performed by using various in vitro spectrophometric assays against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and hydrogen peroxide (H 2 O 2 ). All compounds exhibited high efficiency as antioxidants compared to ascorbic acid. The highest efficiency scavenging activity was found for compound 3 (91.0˘5.0), followed by compounds 2 and 4 (88.0˘2.00; and 87.0˘3.00). Ascorbic acid C was used as a standard drug with a percentage inhibition of 91.00˘1.5. The mechanism of the synthesized compounds as antioxidants was also studied. Hartree-Fock-based quantum chemical studies have been carried out with the basis set to 3-21G, in order to obtain information about the three-dimensional (3D) geometries, electronic structure, molecular modeling, and electronic levels, namely HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital), to understand the antioxidant activity for the synthesized compounds.

Effect of Anti Diabetic Drugs on Lipid Profile in Patients with Type 2 Diabetes Mellitus

“…Patients taking oral hypoglycemic agents other than metformin or glibenclamide and those taking drugs that may affect the results of the study had also been excluded. The sample for the assay were taken early in the morning between (8.30 and 11.00 A.M) while both patient and healthy subjects were relaxed and fasting for (12)(13)(14) hours. A careful history was obtained from patients including age, duration of diabetes, duration of taking treatment, family history, weight and height, type of treatment, other diseases and smoking.…”

Synthesis, Antioxidant Activity, Acetylcholinesterase Inhibition and Quantum Studies of Thiosemicarbazones

“…37 High EA values represent that an electron can be easily added to the species, being directly related to the compound's antioxidant capability. EA = -E LUMO (4) Electronegativity (μ) of thiosemicarbazones 2a-q was obtained using equation 5.…”

“…EA = -E LUMO (4) Electronegativity (μ) of thiosemicarbazones 2a-q was obtained using equation 5. 37 Thus, a compound with a lower electronegativity is expected to have a higher antioxidant activity.…”

“…37 The ionization potential (IP) of thiosemicarbazones 2a-q was obtained using equation 3. 37 Therefore, the lower the energy required to remove an electron, higher is the …”

Green Antioxidants: Synthesis and Scavenging Activity of Coumarin-Thiadiazoles as Potential Antioxidants Complemented by Molecular Modeling Studies

“…7 Moreover, derivatives that functionalized with heterocyclic moieties such as azetidine, thiazolidine, thiazole could considerably increase the medicinal efficiency. 8,9 Free radicals are highly reactive atoms or molecules that have unpaired electron. 10,11 4-hydroxycoumarin and thiadiazoles represent promising scaffolds in the medicinal chemistry field.…”