scholarly journals Isoflavones and Isoflavone Glycosides: Structural-Electronic Properties and Antioxidant Relations—A Case of DFT Study

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Son Ninh The ◽  
Thanh Do Minh ◽  
Trang Nguyen Van
Keyword(s):  
Antioxidant Activities ◽  
Radical Scavenging ◽  
Hydrogen Atom Transfer ◽  
Point Of View ◽  
Basis Set ◽  
Biochanin A ◽  
Dissociation Enthalpy ◽  
B3lyp Method ◽  
Scavenging Capacity ◽  
Antioxidant Reactions

Isoflavonoids and isoflavonoid glycosides have drawn much attention because of their antioxidant radical-scavenging capacity. Based on computational methods, we now present the antioxidant potential results of genistein (1), biochanin A (2), ambocin (3), and tectorigenin 7-O-[β-D-apiofuranosyl-(1-6)-β-D-glucopyranoside] (4). The optimized structures of the neutral and radical forms have been determined by the DFT-B3LYP method with the 6-311G(d) basis set. From the findings and thermodynamic point of view, the ring B system of isoflavones is considered as an active center in facilitating antioxidant reactions. Antioxidant activities are mostly driven by O-H bond dissociation enthalpy (BDE) following hydrogen atom transfer (HAT) mechanism. Antioxidant ability can be arranged in the following order: compounds (4) > (3) > (2) > (1). Of comprehensive structural analysis, flavonoids with 4′-methylation and 6-methoxylation, especially 7-glycosylation would claim responsibility for antioxidant enhancement.

scholarly journals Foeniculum vulgare Essential Oils: Chemical Composition, Antioxidant and Antimicrobial Activities

2010 ◽  
Vol 5 (2) ◽  
pp. 1934578X1000500 ◽  
Author(s):  
Maria Graça Miguel ◽  
Cláudia Cruz ◽  
Leonor Faleiro ◽  
Mariana T. F. Simões ◽  
Ana Cristina Figueiredo ◽  
...  
Keyword(s):  
Essential Oils ◽  
Radical Scavenging ◽  
Antimicrobial Activities ◽  
Point Of View ◽  
Diffusion Method ◽  
Foeniculum Vulgare ◽  
Aerial Parts ◽  
Scavenging Capacity ◽  
Dpph Method ◽  
Main Components

The essential oils from Foeniculum vulgare commercial aerial parts and fruits were isolated by hydrodistillation, with different distillation times (30 min, 1 h, 2 h and 3 h), and analyzed by GC and GC-MS. The antioxidant ability was estimated using four distinct methods. Antibacterial activity was determined by the agar diffusion method. Remarkable differences, and worrying from the quality and safety point of view, were detected in the essential oils. trans-Anethole (31-36%), α-pinene (14-20%) and limonene (11-13%) were the main components of the essentials oil isolated from F. vulgare dried aerial parts, whereas methyl chavicol (= estragole) (79-88%) was dominant in the fruit oils. With the DPPH method the plant oils showed better antioxidant activity than the fruits oils. With the TBARS method and at higher concentrations, fennel essential oils showed a pro-oxidant activity. None of the oils showed a hydroxyl radical scavenging capacity >50%, but they showed an ability to inhibit 5-lipoxygenase. The essential oils showed a very low antimicrobial activity. In general, the essential oils isolated during 2 h were as effective, from the biological activity point of view, as those isolated during 3 h.

ANTIOXIDANT ACTIVITIES OF EXTRACTS FROM THE LEAVES AND STEM BARKS OF Artocarpus scortechinii KING

2015 ◽  
Vol 77 (2) ◽  
Author(s):  
Shajarahtunnur Jamil ◽  
Norazah Basar ◽  
Norzafneza Mohd Arriffin
Keyword(s):  
Ethyl Acetate ◽  
Gallic Acid ◽  
Phenolic Content ◽  
Ethyl Acetate Extract ◽  
Antioxidant Activities ◽  
Radical Scavenging ◽  
Dry Weight ◽  
Calibration Graph ◽  
Total Phenolic ◽  
Scavenging Capacity

The antioxidant activities of extracts (n-hexane, dichloromethane, ethyl acetate and methanol) from the leaves and stem barks of Artocarpus scortechinii were evaluated using various biochemical assays. The quantification of the Total Antioxidant Capacity was measured using ferric reducing antioxidant potential (FRAP) and 2,2'-azino-bis(3-ethyl-benzothiazoline-6-sulphonic acid) (ABTS) assays. While, the qualitative of The Total Phenolic Content (TPC) was determined via standard gallic acid calibration graph which was expressed as mg gallic acid equivalent (GAE)/g of dry weight (dw) using Folin Ciocalteau’s reagent. Among all the extracts tested, the methanolic extract of the stem barks showed the highest phenolic content with TPC value of 136.84 mg GAE/g dry weight (dw). FRAP results were expressed as mM equivalent to FeSO4.7H2O by calculating from the standard FeSO4.7H2O calibration graph. The ethyl acetate extract of the stem barks showed the most significant reducing potential in the range between 0.27-2.47 mM FRAP. ABTS+˙ radical scavenging capacity showed that the ethyl acetate extract of the stem barks had the highest scavenging capacity at concentration 1.0 mM with percentage of 90.9%.

DFT study of free radical scavenging activity of erodiol

2013 ◽  
Vol 67 (11) ◽  
Author(s):  
Zoran Marković ◽  
Jelena Đorović ◽  
Milan Dekić ◽  
Milanka Radulović ◽  
Svetlana Marković ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Hydrogen Atom Transfer ◽  
Free Radical Scavenging ◽  
Single Electron Transfer ◽  
Transfer Energy ◽  
Dissociation Enthalpy ◽  
Proton Dissociation ◽  
Transfer Mechanisms

AbstractAntioxidant activity of erodiol was examined at the M05-2X/6-311+G(d,p) level of theory in the gas and aqueous phases. The structure and energy of radicals and anions of the most stable erodiol rotamer were analyzed. To estimate antioxidant potential of erodiol, different molecular properties were examined: bond dissociation enthalpy, proton affinity together with electron transfer energy, and ionization potential followed by proton dissociation enthalpy. It was found that hydrogen atom transfer is the prevailing mechanism of erodiol behavior in gas; whereas single electron transfer followed by proton transfer and sequential proton loss electron transfer mechanisms represent the thermodynamically preferred reaction paths in water.

scholarly journals Radical-Scavenging and UV-Radiation Absorption Activities of Aaptamine Derivatives: DFT and TD-DFT Studies

2021 ◽  
Author(s):  
Thi Hoai Nam Doan ◽  
Thi Le Anh Nguyen ◽  
Nguyen Thi Ai Nhung ◽  
Duong Tuan Quang ◽  
Duy Quang Dao
Keyword(s):  
Density Functional ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Hydrogen Atom Transfer ◽  
Radiation Absorption ◽  
Functional Theory ◽  
Radical Adduct ◽  
Td Dft ◽  
Potential Applications

Antioxidant and UV absorption activities of three aaptamine derivatives including piperidine[3,2-b]demethyl(oxy)aaptamine (C1), 9-amino-2-ethoxy-8-methoxy-3H-benzo[de][1,6]naphthyridine-3-one (C2), and 2-(sec-butyl)-7,8-dimethoxybenzo[de]imidazo[4,5,1-ij][1,6]-naphthyridin-10(9H)-one (C3) were theoretically studied by density functional theory (DFT). Optimized geometries of C1C3 and theirs intrinsic thermochemical properties such as bond dissociation energy, proton affinity, and ionization potential were calculated at DFT/M05-2X/6-311++G(d,p) level of theory in vacuo and in water. The results show that C1C3 exhibited similar potent antioxidant activities, which are comparable to well-known antioxidants such as Trolox or cembrene. The radical scavenging activity of the antioxidants were then investigated by evaluation the Gibbs free energy (ΔrG0) of the reaction between C1C3 and the HOO●/HO● radicals via four mechanisms, including: hydrogen atom transfer (HAT), single electron transfer (SET), proton loss (PL) and radical adduct formation (RAF). Kinetic calculation reveals that HOO● scavenging in water is occurred via HAT mechanism with C1@C19 while RAF is more dominant with C2 and C3. Antioxidant activity of aaptamine derivatives can be classified as C1 > C3 > C2. In addition, all compounds are active in UV-Vis absorption; the excitations of which are determined as π-π* transition. Overall, the results suggest the potential applications of the aaptamines in pharmaceutics and cosmetics, i.e. as sunscreen and antioxidant ingredient<br>

scholarly journals Phenolic Compounds, Antioxidant Activities, and Inhibitory Effects on Digestive Enzymes of Different Cultivars of Okra (Abelmoschus esculentus)

Molecules ◽  
2020 ◽  
Vol 25 (6) ◽  
pp. 1276
Author(s):  
Ding-Tao Wu ◽  
Xi-Rui Nie ◽  
Dan-Dan Shen ◽  
Hong-Yi Li ◽  
Li Zhao ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Digestive Enzymes ◽  
High Performance ◽  
Antioxidant Activities ◽  
Radical Scavenging ◽  
Natural Antioxidants ◽  
Inhibitory Effects ◽  
Antioxidant Power ◽  
Radical Scavenging Capacity ◽  
Scavenging Capacity

In this study, the phenolic profiles and bioactivities of five representative cultivars of okra collected in China were investigated. Noticeable variations of phenolic compounds and their bioactivities were observed among these different cultivars of okra. The contents of total flavonoids (TFC) in “Shuiguo”, “Kalong 8”, “Kalong 3”, “Wufu”, and “Royal red” ranged from 1.75 to 3.39 mg RE/g DW, of which “Shuiguo” showed the highest TFC. Moreover, five individual phenolic compounds were found in okra by high performance liquid chromatography analysis, including isoquercitrin, protocatechuic acid, quercetin-3-O-gentiobioside, quercetin, and rutin, while isoquercitrin and quercetin-3-O-gentiobioside were detected as the main phenolic compounds in okra. Moreover, all tested okra exhibited significant antioxidant activities (2,2-diphenyl-1-picrylhydrazyl radical scavenging capacity, 2,2’-azino-bis (3-ethylenzthiazoline-6-sulphonic acid) radical scavenging capacity, and ferric reducing antioxidant power) and inhibitory effects on digestive enzymes (lipase, α-glucosidase, and α-amylase). Indeed, “Shuiguo” exhibited much better antioxidant activities and inhibitory activities on digestive enzymes, which might be attributed to its high TFC. Results suggested that okra, especially “Shuiguo”, could be developed as natural antioxidants and inhibitors against hyperlipidemia and hyperglycemia in the fields of functional foods and pharmaceuticals, which could meet the increasing demand for high-quality okra with health-promoting properties in China.

scholarly journals Comparative analysis of the polyphenols profiles and the antioxidant and cytotoxicity properties of various blue honeysuckle varieties

2018 ◽  
Vol 16 (1) ◽  
pp. 637-646 ◽  
Author(s):  
Yuehua Wang ◽  
Xu Xie ◽  
Xulong Ran ◽  
Shurui Chou ◽  
Xinyao Jiao ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Activities ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Natural Antioxidants ◽  
Bioactive Components ◽  
Fruit Peel ◽  
Scavenging Capacity ◽  
Polyphenol Profile ◽  
Blue Honeysuckle

AbstractThe polyphenol profile, antioxidant activity (particularly peroxyl radical-scavenging capacity (PSC) and cellular antioxidant activity (CAA)) and cytotoxicity of extracts from seven varieties of blue honeysuckle were compared in this study. Moreover, an analysis of correlations between individual polyphenol profiles and antioxidant activities was also conducted. Seventeen components were found in the investigated blue honeysuckle extracts, with anthocyanins being the prominent bioactive components among polyphenols. Fruit peel contained higher concentrations of individual anthocyanins compared to the fruit pulp. Beilei blue honeysuckle had the highest antioxidant activity. Correlation analysis showed that antioxidant activity values were highly associated with cyanidin-3-glucoside levels. Blue honeysuckle extracts were not cytotoxic over the range of doses tested. Among the varieties analyzed, Beilei possessed the highest antioxidant properties and was found to be the most appropriate source of natural antioxidants.

Evaluation of Antioxidant Activities of Alpinia galanga (L.) Willd

2018 ◽  
Vol 15 (4) ◽  
pp. 899-908
Author(s):  
Khoirom Ratipiyari Devi ◽  
Paonam Priyobrata Singh ◽  
Moirangthem Medhapati Devi ◽  
Gurumayum Jitendra Sharma
Keyword(s):  
Free Radical ◽  
Plant Extracts ◽  
Antioxidant Activities ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Total Phenolic ◽  
Alpinia Galanga ◽  
Radical Scavenging Capacity ◽  
Scavenging Capacity ◽  
Promising Source

Present research was designed to evaluate the free radical scavenging capacities and antioxidant activities of rhizome extracts of Alpinia galanga prepared in different solvent systems (60% aqueous methanol, 60% aqueous ethanol and distilled water) using different in vitro chemical assays. Antioxidant components such as total phenolic content (TPC), total flavonoid content (TFC) and ascorbic acid contents of the ginger species were screened. Antioxidant assays employed included sulphur free radical reactivity assay, ferric ion reducing power assay, DPPH free radical scavenging capacity assay, hydroxyl radical scavenging assay, nitric oxide scavenging activity assay and hydrogen peroxide scavenging assay. The obtained data reveal that the plant extracts contained significant amount of the observed antioxidant components and also exhibited significant free radical scavenging capacities. Methanol (60%) extract exhibited highest antioxidant activity than other solvents. The polyphenolic constituents of the plant extracts appear to be largely responsible for the radical scavenging capacity. The plant extracts act as promising source of antioxidants, and may be useful for development of nutraceuticals and pharmaceutical drugs.

scholarly journals Free Radical Scavenging Activity of Dihydrocaffeic Acid: A Quantum Chemical Approach

2021 ◽  
Vol 33 (4) ◽  
pp. 937-944
Author(s):  
K. Senthilkumar ◽  
S.S. Naina Mohammed ◽  
S. Kalaiselvan
Keyword(s):  
Electron Transfer ◽  
Quantum Chemical ◽  
Density Functional ◽  
Radical Scavenging ◽  
Hydrogen Atom Transfer ◽  
Basis Set ◽  
Published Data ◽  
Chemical Calculation ◽  
Neutral Radical ◽  
Donor And Acceptor

Based on density functional theory (DFT), to investigate relationships between the antioxidant activity and structure of dihydrocaffeic acid, quantum chemical calculation is used. The optimized structures of the neutral, radical and ionic forms have been carried out by DFT-B3LYP method with the 6-311G(d,p) basis set. Reaction enthalpies related with the hydrogen atom transfer (HAT), single electron transfer proton transfer (SET-PT) and sequential proton loss and electron transfer (SPLET) were calculated in gas and water phase. The HOMO-LUMO energy gap, electron affinity, electronegativity, ionization energy, hardness, chemical potential, global softness and global electrophilicity were calculated by using the same level of theory. Surfaces with a molecular electrostatic potential (MEP) were studied to determine the reactive sites of dihydrocaffeic acid. The difference in energy between the donor and acceptor as well as the stabilization energy was determined through the natural bond orbital (NBO) analysis. The Fukui index (FI) based on electron density was employed to predict reaction sites. Reaction enthalpies are compared with previously published data for phenol and 3,4-dihydroxycinnamic acid.

Synthesis, Characterization, Free-radical Scavenging Capacity and Antioxidant Activity of Novel Series of Hydrazone, 1,3,4-oxadiazole and 1,2,4- triazole Derived from 3,5-dimethyl-1H-pyrazole

2019 ◽  
Vol 16 (7) ◽  
pp. 712-720 ◽  
Author(s):  
Khalid Karrouchi ◽  
Saad Fettach ◽  
Smaail Radi ◽  
El bekkaye Yousfi ◽  
Jamal Taoufik ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Free Radical ◽  
Antioxidant Activities ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Radical Scavenging Capacity ◽  
Scavenging Capacity ◽  
Anti Cancer ◽  
Ic50 Values

Background: Pyrazole is an important class of heterocyclic compound, has been shown to exhibit diverse biological and pharmacological activities such as anti-inflammatory, anti-cancer, antioxidant, etc. Methods: In this study, a series of novel 3,5-dimethyl-1H-pyrazole derivatives containing hydrazine 4a-l have been synthesized via the reaction of the 2-(3,5-dimethyl-1H-pyrazol-1-yl)acetohydrazide. All synthesized compounds have been tested for their in vitro antioxidant activities via utilization of 1,1-biphenyl-2-picrylhydrazyl (DPPH) as a free radical scavenging reagent. Results: The data reported herein indicates that compound 4k showed potential radical scavenging capacity and compounds 4f and 4g exhibited best activity for the iron binding while comparing with positive controls. Conclusion: Good activity was noted for some compounds. In particular, compound 4k showed the highest antioxidant activity with IC50 values of 22.79 ± 3.64 and 1.35 ± 0.66 μg/mL in the DPPH and ABTS tests, respectively.

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