title: 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 (H2O2). 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.
authors.affiliation: Department of Chemical &amp; Process Engineering, University Kebangsaan Malaysia (UKM), Bangi, Selangor 43000, Malaysia. yasmin.chem79@gmail.com.
authors.forename: Yasameen K
authors.initials: YK
authors.lastname: Al-Majedy
authors.affiliation: Department of Pharmaceutical Chemistry, College of Pharmacy, Kufa University, Najaf 31001, Iraq. dunialafta1982@yahoo.com.
authors.forename: Dunya L
authors.initials: DL
authors.lastname: Al-Duhaidahawi
authors.affiliation: Branch of Chemistry, Department of Applied Science, University of Technology (UOT), Baghdad 10001, Iraq. Khalidachemistry@gmail.com.
authors.forename: Khalida F
authors.initials: KF
authors.lastname: Al-Azawi
authors.affiliation: Department of Chemical &amp; Process Engineering, University Kebangsaan Malaysia (UKM), Bangi, Selangor 43000, Malaysia. dr.ahmed75@ukm.edu.my.|Branch of Chemistry, Department of Applied Science, University of Technology (UOT), Baghdad 10001, Iraq. dr.ahmed75@ukm.edu.my.
authors.forename: Ahmed A
authors.initials: AA
authors.lastname: Al-Amiery
authors.affiliation: Department of Chemical &amp; Process Engineering, University Kebangsaan Malaysia (UKM), Bangi, Selangor 43000, Malaysia. amir@eng.ukm.my.
authors.forename: Abdul Amir H
authors.initials: AA
authors.lastname: Kadhum
authors.affiliation: Department of Chemical &amp; Process Engineering, University Kebangsaan Malaysia (UKM), Bangi, Selangor 43000, Malaysia. drab@eng.ukm.my.
authors.forename: Abu Bakar
authors.initials: AB
authors.lastname: Mohamad
mesh_terms: D000975:Antioxidants / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000494:pharmacology; D001713:Biphenyl Compounds / Q000378:metabolism; D003374:Coumarins / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D006861:Hydrogen Peroxide / Q000378:metabolism; D008958:Models, Molecular; D015394:Molecular Structure; D010851:Picrates / Q000378:metabolism
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D003374:Coumarins; D010851:Picrates; D006861:Hydrogen Peroxide; C004931:1,1-diphenyl-2-picrylhydrazyl; D001205:Ascorbic Acid
keywords: DPPH; H2O2; antioxidant activity; coumarin