Free radical scavenging mechanism of 1,3,4-oxadiazole derivatives: thermodynamics of O–H and N–H bond cleavage

Alisi, Ikechukwu Ogadimma; Uzairu, Adamu; Abechi, Stephen Eyije

doi:10.1016/j.heliyon.2020.e03683

Cited by 25 publications

(17 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…most preferential site for hydrogen donation in both the compounds, whereas the SPLET mechanism was favored in polar solvents. An antioxidant molecule like 1,3,4-oxadiazole the preferred site for HAT was the same as that of SPLET for each molecule (Alisi, Uzairu, & Abechi, 2020).…”

Section: F I G U R Ementioning

confidence: 99%

Concept, mechanism, and applications of phenolic antioxidants in foods

2020

View full text Add to dashboard Cite

In this review, the concept of phenolic antioxidants, mechanisms of action, and applications have been reviewed. Phenolic compounds (PCs) acts as an antioxidant by reacting with a variety of free radicals. The mechanism of antioxidant actions involved either by hydrogen atom transfer, transfer of a single electron, sequential proton loss electron transfer, and chelation of transition metals. In foods, the PCs act as antioxidants which are measured with several in vitro spectroscopic methods. The PCs have been found in milk and a wide range of dairy products with sole purposes of color, taste, storage stability, and quality enhancement. The role of PCs in three types of food additives, that is, antimicrobial, antioxidant, and flavoring agents have been critically reviewed. The literature revealed that PCs present in a variety of foods possess several health benefits such as antibacterial, antihyperlipidemic, anticancer, antioxidants, cardioprotective, neuroprotective, and antidiabetic properties. Practical applications Phenolic compounds are strong antioxidants and are safer than synthetic antioxidants. The wide occurrence in plant foods warranted continuous review applications. This review, therefore, presented an updated comprehensive overview of the concept, mechanism, and applications of phenolic antioxidants in foods.

show abstract

Section: F I G U R Ementioning

confidence: 99%

Concept, mechanism, and applications of phenolic antioxidants in foods

2020

View full text Add to dashboard Cite

show abstract

“…The total species enthalpies were calculated as the sum of total electronic energy, zero-point energy and the translational, rotational, and vibrational contributions to the total enthalpy as presented in Equation (6). In order to convert the energy to enthalpy, the RT (PV-work) term was added [43].…”

Section: Computation Of Antioxidant Descriptorsmentioning

confidence: 99%

Biological Evaluation of 4-(1H-triazol-1-yl)benzoic Acid Hybrids as Antioxidant Agents: In Vitro Screening and DFT Study

et al. 2021

View full text Add to dashboard Cite

Fourteen triazole benzoic acid hybrids were previously characterized. This work aimed to screen their in vitro antioxidant activity using different assays, i.e., DPPH (1,1-diphenyl-1-picrylhydrazyl), reducing the power capability, FRAP (ferric reducing antioxidants power) and ABTS (2,2′-azino-bis(3-ethylben zothiazoline-6-sulfonate) radical scavenging. The 14 compounds showed antioxidant properties in relation to standard BHA (butylated hydroxylanisole) and Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid). Higher antioxidant activity was observed by the parent (1) at a concentration of 100 µg/mL (89.95 ± 0.34 and 88.59 ± 0.13%) when tested by DPPH and ABTS methods in relation to BHA at 100 µg/mL (95.02 ± 0.74 and 96.18 ± 0.33%). The parent (2) demonstrated remarkable scavenging activity when tested by ABTS (62.00 ± 0.24%), however, 3 was less active (29.98 ± 0.13%). Compounds 5, 6, 9, and 11 exhibited good scavenging activity compared to 1. DFT studies were performed using the B3LYP/6-311++g (2d,2p) level of theory to evaluate different antioxidant descriptors for the targets. Three antioxidant mechanisms, i.e., hydrogen atom transfer (HAT), sequential electron transfer proton transfer (SETPT) and sequential proton loss electron transfer (SPLET) were suggested to describe the antioxidant properties of 1–14. Out of the 14 triazole benzoic acid hybrids, 5, 9, 6, and 11 showed some good theoretical results, which were in agreement with some experimental outcomes. Based on the computed (PA and ETE) and (BDE and IP) values in (SPLET) and (HAT and SETPT) mechanisms, respectively, compound 9 emerged has having good antioxidant activity.

show abstract

“…Antioxidants such as phenolic compounds and aromatic amines protect free radical intermediates and reactive oxygen/nitrogen species in biological systems and synthetic products [1][2][3][4][5][6][7][8][9]. The radical scavenging mechanism is initiated by abstracting a hydrogen atom from the antioxidants [10][11][12][13][14][15][16][17]. The energy calculation for the breakage of a hydrogen bond is essential for understanding the antioxidant scavenging mechanism and is also fundamental for various chemical and biochemical transformations [10][11][18][19][20].…”

Section: ■ Introductionmentioning

confidence: 99%

Rotational Barrier and Bond Dissociation Energy and Enthalpy: Computational Study of the Substituent Effects in <i>Para</i>-Substituted Anilines and Phenols

Yateem

2022

Indones. J. Chem.

View full text Add to dashboard Cite

This report presents the N–H and O–H bond dissociation energies (BDEs) and enthalpies (BDEts) of 27 para-substituted anilines and phenols using Density Functional Theory (DFT) with functional wB97X-D and basis set 6-31G**. The computed BDEs/ BDEts show a strong correlation with the calculated rotational barrier (RB) around phenyl–NH2 and phenyl–OH bonds of the parent neutral molecules. Electron-withdrawing (EW) substituents increased RB and BDEs/BDEts, while electron-donating (ED) substituents caused opposite behavior. Geometric, atomic, molecular, and spectroscopic properties of NH2 and OH groups in neutral anilinic and phenolic molecules exhibited excellent correlations with RB and BDEs/BDEts. The geometry around heteroatoms of the radicals displayed constant geometrical changes for all substituents. Spin density maps confirmed that the unpaired electrons in radicals are delocalized in heteroatoms and phenyl rings for all the para-substituents. Spin delocalization in both types of radicals was further enhanced in the presence of para-ED substituents. The increase in electronic density around heteroatoms of radicals with the strength of ED substituents was found proportional to that in neutral molecules. Therefore, the N–H and O–H BDE/BDEt are mainly governed by the stabilization/destabilization of the neutral molecules and, to a significantly lower extent, the stabilization of radicals in the case of strong ED groups.

show abstract

Free radical scavenging mechanism of 1,3,4-oxadiazole derivatives: thermodynamics of O–H and N–H bond cleavage

Cited by 25 publications

References 53 publications

Concept, mechanism, and applications of phenolic antioxidants in foods

Concept, mechanism, and applications of phenolic antioxidants in foods

Biological Evaluation of 4-(1H-triazol-1-yl)benzoic Acid Hybrids as Antioxidant Agents: In Vitro Screening and DFT Study

Rotational Barrier and Bond Dissociation Energy and Enthalpy: Computational Study of the Substituent Effects in <i>Para</i>-Substituted Anilines and Phenols

Contact Info

Product

Resources

About