scholarly journals Theoretical investigations on the antioxidant potential of a non-phenolic compound thymoquinone: a DFT Approach

2021 ◽  
Author(s):  
Jewel Hossen ◽  
M. Abbas Ali ◽  
Sultanur Reza
Keyword(s):  
Antioxidant Activity ◽  
Free Radical ◽  
Density Functional ◽  
Nigella Sativa ◽  
Radical Scavenging ◽  
Hydroxyl Group ◽  
Black Cumin ◽  
Theoretical Investigations ◽  
Water Media ◽  
Thermochemical Parameters

Abstract Thymoquinone (TQ) is a natural compound occurred in black cumin ( Nigella sativa L.), which possesses potent antioxidant activity without having any phenolic hydroxyl group believed to be responsible for antioxidant activity of a molecule. In the present study, computational calculation based on Density Functional Theory (DFT) have been executed to assess systematically the worth of antioxidant behavior of this compound. Geometrical characteristics, HOMO-LUMO and MEP surface have been studied. Thermochemical parameters correlated to the leading antioxidant mechanisms such as HAT, SETPT and SPLET have been studied in gas and water media. In addition, the changes of thermochemical parameters such as ∆G and ∆H have been computed for HA from TQ to hydroxyl radical in gas and water phases to investigate its free radical scavenging potency. The low and comparable values of BDE, PDE, IP, PA and ETE suggest the antioxidant activity. The ∆G and ∆H also convey apposite thermodynamic evidence in favor of antiradical capability of TQ. The attack of the free radical takes place preferentially at 3CH position of the molecule.

scholarly journals In Vitro and In Silico Antioxidant Activity of Novel Peptides Prepared from Paeonia Ostii ‘Feng Dan’ Hydrolysate

Antioxidants ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 433 ◽  
Author(s):  
Min Wang ◽  
Cong Li ◽  
Haoyu Li ◽  
Zibo Wu ◽  
Bang Chen ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Free Radical ◽  
In Silico ◽  
Density Functional ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Basis Set ◽  
Superior Performance ◽  
Antioxidant Peptides

Antioxidant peptides derived from natural products have superior performance and broader application prospects. In this study, five novel antioxidant peptides were prepared from Paeonia ostii (P. ostii) seed meal, moreover the bioactive and the relationship between structure and properties of antioxidant peptides were elucidated by quantum chemical calculations. The free radical-scavenging activities were used as indexes to purify and concentrate the antioxidant peptides through five proteases and separation techniques. FSAP (Phe-Ser-Ala-Pro), PVETVR (Pro-Val-Glu-Thr-Val-Arg), QEPLLR (Gln-Glu-Pro-Leu-Leu-Arg), EAAY (Glu-Ala-Ala-Tyr) and VLRPPLS (Val-Leu-Arg-Pro-Pro-Leu-Ser) were identified by nano liquid chromatography–tandem mass spectrometry (LC-MS/MS). In vitro antioxidant activity test, EAAY exhibited the highest 2, 2’-azino-bis (ABTS) and hydroxyl radical-scavenging activity of 98.5% ± 1.1% and 61.9% ± 1.3%, respectively (p < 0.01), at 0.5 mg/mL. In silico calculations were carried out using the density functional theory (DFT) with the B3LYP/6-31G* basis set. According to natural bond orbital (NBO) analysis, the bioactivity of free-radical scavenging of the peptides was presumed. Moreover, the antioxidant peptides demonstrated no obvious cytotoxicity to L929 fibroblast cells. Therefore, the peptides from P. ostii seed by-products might potentially have excellent uses in functional foods, nutraceuticals and pharmacological products.

scholarly journals Relationships between Structure and Antioxidant Capacity and Activity of Glycosylated Flavonols

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 849
Author(s):  
Zhengcao Xiao ◽  
Liangliang He ◽  
Xiaohui Hou ◽  
Jianping Wei ◽  
Xiaoyu Ma ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Free Radical ◽  
Antioxidant Capacity ◽  
Sulfonic Acid ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Hydroxyl Group ◽  
Dpph Assay ◽  
Dimer Formation ◽  
Abts Assay

The antioxidant capacity (AC) and antioxidant activity (AA) of three flavonols (FLV), aglycones and their glycosylated derivatives were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays in various solvents. Findings confirmed that the glycosylation at the 3-position (3-glycosylation) always decreased the AC under most conditions due to substitution of the 3-position hydroxyl group and glycoside disruption in the molecular planarity. The 7-glycosylated derivatives did not have the above effects, thus generally exhibited ACs similar to their aglycones. Glycosylation decreased the AA of kaempferol and isorhamnetin for both assays in methanol, 3-glycosylation inhibited quercetin AA in the ABTS assay. In the DPPH assay, the AA of 3-glycosylated quercetin was significantly higher than quercetin. Using LC–MS/MS analysis, we found that quercetin and quercetin-7-glucoside underwent dimerization during the antioxidant reaction, potentially leading to a decline in AAs. However, 3-glycoside substitution may have hindered dimer formation, thereby allowing the FLVs to retain strong free radical scavenging abilities.

scholarly journals Microwave-Assisted Synthesis, Characterization, Antimicrobial and Antioxidant Activity of Some New Isatin Derivatives

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
G. Kiran ◽  
T. Maneshwar ◽  
Y. Rajeshwar ◽  
M. Sarangapani
Keyword(s):  
Antioxidant Activity ◽  
Free Radical ◽  
Radical Scavenging ◽  
Microwave Assisted Synthesis ◽  
Stable Free Radical ◽  
Ft Ir ◽  
Antimicrobial And Antioxidant Activity ◽  
New Compounds ◽  
Isatin Derivatives

A series of β-Isatin aldehyde-N,N′-thiocarbohydrazone derivatives were synthesized and assayed for theirin vitroantimicrobial and antioxidant activity. The new compounds were characterized based on spectral (FT-IR, NMR, MS) analyses. All the test compounds possessed a broad spectrum of activity having MIC values rangeing from 12.5 to 400 μg/ml against the tested microorganisms. Among the compounds3e,3jand3nshow highest significant antimicrobial activity. The free radical scavenging effects of the test compounds against stable free radical DPPH (α,α-diphenyl-β-picryl hydrazyl) and H2O2were measured spectrophotometrically. Compounds3j,3n,3l, and3e, respectively, had the most effective antioxidant activity against DPPH and H2O2scavenging activity.

scholarly journals Characterization of Phytoconstituents from Alcoholic Extracts of Four Woody Species and Their Potential Uses for Management of Six Fusarium oxysporum Isolates Identified from Some Plant Hosts

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1325
Author(s):  
Mohamed Z. M. Salem ◽  
Abeer A. Mohamed ◽  
Hayssam M. Ali ◽  
Dunia A. Al Al Farraj
Keyword(s):  
Antioxidant Activity ◽  
Free Radical ◽  
Benzoic Acid ◽  
Fusarium Oxysporum ◽  
Leaf Extract ◽  
Antioxidant Activities ◽  
Radical Scavenging ◽  
Bark Extract ◽  
Leaf Extracts ◽  
Conium Maculatum

Background: Trees are good sources of bioactive compounds as antifungal and antioxidant activities. Methods: Management of six molecularly identified Fusarium oxysporum isolates (F. oxy 1, F. oxy 2, F. oxy 3, F. oxy 4, F. oxy 5 and F. oxy 6, under the accession numbers MW854648, MW854649, MW854650, MW854651, and MW854652, respectively) was assayed using four extracts from Conium maculatum leaves, Acacia saligna bark, Schinus terebinthifolius wood and Ficus eriobotryoides leaves. All the extracts were analyzed using HPLC-VWD for phenolic and flavonoid compounds and the antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and β-carotene-linoleic acid (BCB) bleaching assays. Results: In mg/kg extract, the highest amounts of polyphenolic compounds p-hydroxy benzoic, benzoic, gallic, and rosmarinic acids, with 444.37, 342.16, 311.32 and 117.87, respectively, were observed in C. maculatum leaf extract; gallic and benzoic acids with 2551.02, 1580.32, respectively, in A. saligna bark extract; quinol, naringenin, rutin, catechol, and benzoic acid with 2530.22, 1224.904, 798.29, 732.28, and 697.73, respectively, in S. terebinthifolius wood extract; and rutin, o-coumaric acid, p-hydroxy benzoic acid, resveratrol, and rosmarinic acid with 9168.03, 2016.93, 1009.20, 1156.99, and 574.907, respectively, in F. eriobotryoides leaf extract. At the extract concentration of 1250 mg/L, the antifungal activity against the growth of F. oxysporum strains showed that A. saligna bark followed by C. maculatum leaf extracts had the highest inhibition percentage of fungal growth (IPFG%) against F. oxy 1 with 80% and 79.5%, F. oxy 2 with 86.44% and 78.9%, F. oxy 3 with 86.4% and 84.2%, F. oxy 4 with 84.2, and 82.1%, F. oxy 5 with 88.4% and 86.9%, and F. oxy 6 with 88.9, and 87.1%, respectively. For the antioxidant activity, ethanolic extract from C. maculatum leaves showed the lowest concentration that inhibited 50% of DPPH free radical (3.4 μg/mL). Additionally, the same extract observed the lowest concentration (4.5 μg/mL) that inhibited BCB bleaching. Conclusions: Extracts from A. saligna bark and C. maculatum leaves are considered potential candidates against the growth of F. oxysporum isolates—a wilt pathogen—and C. maculatum leaf as a potent antioxidant agent.

Changes in antioxidant activity and free radical scavenging potential of rosemary extract and tocopherols in isolated rapeseed oil triacylglycerols during accelerated tests

2005 ◽  
Vol 93 (2) ◽  
pp. 227-235 ◽  
Author(s):  
Malgorzata Nogala-Kalucka ◽  
Jozef Korczak ◽  
Małgorzata Dratwia ◽  
Eleonora Lampart-Szczapa ◽  
Aleksander Siger ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Free Radical ◽  
Rapeseed Oil ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Rosemary Extract ◽  
Accelerated Tests

Antioxidant Activity of Silk Fibroin Peptide Hydrolyzed by Pancreatin

2014 ◽  
Vol 1081 ◽  
pp. 110-114 ◽  
Author(s):  
Zhen Zhu ◽  
Hua Yin ◽  
Yan An
Keyword(s):  
Antioxidant Activity ◽  
Free Radical ◽  
Nitrogen Content ◽  
Silk Fibroin ◽  
Radical Scavenging ◽  
Amino Nitrogen ◽  
Free Radical Scavenging ◽  
Hydrolysis Process ◽  
Superoxide Free Radical ◽  
Hydrolysis Of

This research adopts the pancreatin hydrolysis of silk fibroin active peptide, evaluate the antioxidant activity of hydrolysates. In the process of hydrolysis of silk fibroin, by measuring the amino nitrogen content of neutral formaldehyde titration method. Find the amino nitrogen content gradually stabilized at around 0.37g/L, and superoxide free radical scavenging rate changing with time fluctuation trend, superoxide free radical scavenging rate to a maximum of 65.03% at 220min.The use of silk fibroin hydrolysis process optimization,reaction time 160min, enzyme concentration4% , substrate concentration 20mg/ml, pH 8, temperature 38°C. The hydrolysis process under the hydrolysate on superoxide radical scavenging rate of 72.73%. The scavenging rate of hydroxyl radical is 47.24%. Red blood cell hemolysis induced by H2O2 inhibition rate was 24.30%.

scholarly journals EVALUATION OF ANTIOXIDANT AND FREE RADICAL SCAVENGING ACTIVITIES OF DIFFERENT SOLVENT EXTRACTS OF LEAVES OF PIPER UMBELLATUM

2017 ◽  
Vol 10 (2) ◽  
pp. 274
Author(s):  
Sethupandian Geetha ◽  
Kokkaiah Irulandi ◽  
Palanichamy Mehalingam
Keyword(s):  
Antioxidant Activity ◽  
Free Radical ◽  
Ethyl Acetate ◽  
Methanol Extract ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Free Radical Scavenging ◽  
Frap Assay ◽  
Radical Scavenging Properties

Objective: This study was designed to determine the Total phenol, flavonoid content, antioxidant and free radical scavenging properties of different solvent extracts of Piper umbellatum.  Methods: Different solvent extracts evaluated with DPPH radical scavenging activity and Reducing power activity.Results: The presence of phenol and flavonoid showed highly in the methanol extracts than ethyl acetate and acetone extracts. All the extracts have various level of antioxidant activity. Methanol solvent extract have good extraction and show significant antioxidant activity. The effect of reducing power of methanol extract revealed good antioxidant activity compare with other tested extracts.Conclusion: On the basis of the above results we concluded that methanol extract of Piper umbellatum whole plant extracts shows significant antioxidant activity than ethyl acetate and acetone extracts.Keywords: Piper umbellatum, Antioxidant, DPPH, FRAP assay, Polar, Non polar solvents

scholarly journals Research antioxidant activity of chitooligosacchride by UV-VIS absorption spectrocopy

2020 ◽  
Vol 8 (1) ◽  
pp. 75-81
Author(s):  
Bui Van Hoai ◽  
Ngo Dai Nghiep ◽  
Dao An Quang ◽  
Nguyen Thi Nam Phuong
Keyword(s):  
Molecular Weight ◽  
Antioxidant Activity ◽  
Absorption Spectrum ◽  
Free Radical ◽  
Trichoderma Viride ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Free Radical Scavenging ◽  
Degree Of Deacetylation ◽  
Radical Scavenging Ability

Chitosan with 80% degree of deacetylation was hydrolyzed by cellulase of Trichoderma viride to prepare chitooligosaccharides (COSs) by the fractionation of the COSs with ultrafiltration membrane. The antioxidant activities of the COSs were clarified in this study by reducing power and free radical scavenging ability assay by UV-VIS absorption spectrum. The results show that the COS 1 (10,000-5,000 Da), COS 2 (5,000-3,000 Da), COS 3 (3,000-1,000 Da) and COS 4 (less than1,000 Da) segments have antioxidant properties.The antioxidant activitives of the COSs increased with the increment of concentration, and they also depended on molecular weight.

scholarly journals Thymus algeriensis and Artemisia herba-alba Essential Oils: Chemical Analysis, Antioxidant Potential and In Vivo Anti-Inflammatory, Analgesic Activities, and Acute Toxicity

Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6780
Author(s):  
Khadija El Ouahdani ◽  
Imane Es-safi ◽  
Hamza Mechchate ◽  
Mohammed Al-zahrani ◽  
Ashraf Ahmed Qurtam ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Free Radical ◽  
Medicinal Plants ◽  
Essential Oils ◽  
Iron Reduction ◽  
Radical Scavenging ◽  
Bioactive Molecules ◽  
Potential Toxicity ◽  
Thymus Algeriensis ◽  
Anti Inflammatory

The study of bioactive molecules of natural origin is a focus of current research. Thymus algeriensis and Artemisia herba-alba are two medicinal plants widely used by the Moroccan population in the traditional treatment of several pathologies linked to inflammation. This study aimed to evaluate the single and combined antioxidant, anti-inflammatory and analgesic effects of the essential oils extracted from these two medicinal plants, and also their potential toxicity. Essential oils were extracted using hydro-distillation in a Clevenger-type apparatus. The antioxidant activity was evaluated by two methods: the scavenging of the free radical DPPH, and the reduction in iron. Anti-inflammatory activity was evaluated by evaluating the edema development induced by carrageenan injecting, while the analgesic power was evaluated according to the number of abdominal contortions induced by the intraperitoneal injection of acetic acid (0.7%). The acute oral toxicity was performed to assess the potential toxicity of the studied EOs, followed by an analysis of the blood biochemical parameters. The results of the two antioxidant tests indicated that our extract mixture exhibits good iron reduction capacity and very interesting DPPH free radical scavenging power, with an IC50 of around 4.38 ± 0.98 μg/mL higher than that of the benchmark antioxidant, BHT. The anti-inflammatory test demonstrated that the mixture administered orally at a dose of 150 mg/kg has a better activity, exceeding that of 1% Diclofenac, with a percentage of maximum inhibition of the edema of 89.99 ± 4.08. The number of cramps in the mice treated with the mixture at a dose of 150 mg/kg is significantly lower (29.80 ± 1.92) than those of the group treated with Tramadol (42.00 ± 2.70), respectively. The toxicity results show no signs of toxicity with an LD50 greater than 150 mg/Kg. These interesting results show that the two plants’ EOs had an important anti-inflammatory, analgesic, and antioxidant activity, and also a powerful synergistic effect, which encourages further in-depth investigations on their pharmacological proprieties.

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