Study on the Chemical Structures and Free Radical Scavenging Ability of Anthraquinones and Its c-Glycosides from Rumexjaponicus Houtt.

2021 ◽  
Vol 15 (3) ◽  
pp. 360-368
Author(s):  
Juntong Wang ◽  
Le Gu ◽  
Dandan Xiao ◽  
Xueyu Wang ◽  
Xiaowen Zhen ◽  
...  
Keyword(s):  
Skin Diseases ◽  
Radical Scavenging ◽  
Flavonoid Glycoside ◽  
Hydrogen Atoms ◽  
Oh Groups ◽  
Chemical Structures ◽  
Scavenging Capacity ◽  
Spin Resonance ◽  
Rumex Japonicus ◽  
Radical Scavenging Ability

Rumex japonicus Houtt. (RJH) is a kind of Traditional Chinese Medicine (TCM) widely used in the treatment of serious skin diseases such as psoriasis. To further explore its bioactive components, the five-year root of RJH was used, the nuclear magnetic resonance (NMR) technique was employed with DMSO-d6 solvent for chemical structures, the scavenging capacity of the free radicals (DPPH, alkyl, –OH, and ˙O−2) was evaluated by electron spin resonance (ESR) method. In the results, seven compounds that were wholly characterized as anthraquinones (1 and 2), its c-glycosides (4–7), and flavonoid glycoside (3) especially for the hydrogen atoms from –OH groups located at phenol rings and glucose moieties. The compound 4 and 5 showed the significant bioac-tivity with the IC50 values (DPPH: 23.34 and 23.25 μM; alkyl: 20.27 and 20.15 μM; –OH: 26.03 and 25.50 μM; and ˙O−2: 14.69 and 14.68 μM, respectively). In conclusion, the DMSO-d6 solvent could make active protons be expressed clearly for accurate assignments. The compounds 4 and 5 could be suggested to be applied for potential candidates for related drugs.

Peroxyl Radical Scavenging Ability of Fifty Kinds of Chinese Medicines Determined by an ESR Spin-Trapping Technique

2012 ◽  
Vol 549 ◽  
pp. 327-330
Author(s):  
Fu Hai Wang ◽  
Cheng Hua Huang
Keyword(s):  
Peroxyl Radical ◽  
Radical Scavenging ◽  
Herbal Medicines ◽  
Spin Trapping ◽  
Chinese Medicines ◽  
Esr Spin Trapping ◽  
Spin Resonance ◽  
Radical Scavenging Ability ◽  
Thermolysis Reaction ◽  
Spin Trapping Technique

The peroxyl radical scavenging abilities of fifty Chinese herbal medicines were determined accurately by an electron spin resonance (ESR) spin-trapping technique using 5,5-dimethyl-1-pyrroline 1-oxide (DMPO) as a spin-trapping reagent. The peroxyl radical was generated by the thermolysis reaction of 2,2’-Azobis(isobutyronitrile) (AIBN) in the presence of the spin-tap DMPO and with or without sample. As a result of these studies, a strong scavenging ability of peroxyl radical was found in Chinese medicines for diseases of anti-aging and blood circulation.

scholarly journals Effects of Solvents on the In-vitro Antioxidant Activity of Dennettia tripetala G. Baker and Milicia excelsa (Welw.) C. Berg Root Extracts

2018 ◽  
Author(s):  
Nwachukwu Ekere ◽  
Tochukwu Okparanozie ◽  
Matthias Agbo
Keyword(s):  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Root Extracts ◽  
Scavenging Capacity ◽  
Dennettia Tripetala ◽  
Ic50 Values ◽  
Ethanol Extracts ◽  
Radical Scavenging Ability ◽  
Milicia Excelsa

Background and Purpose: The root extracts of Dennettia tripetala G. Baker and Milicia excelsa (Welw.) C. Berg was investigated for their in-vitro antioxidant activities.Materials and Methods:  The pulverized roots of Dennettia tripetala and Milicia excelsa were extracted separately by cold maceration using ethyl acetate, methanol, n-butanol and water respectively as the extracting solvents. In-vitro antioxidant, the activity of root extracts was then investigated using DPPH model. The results obtained was analyzed using One-way Analysis of Variance (ANOVA) involving GraphPad Prism 5 Software.Results: The antioxidant assay of various extracts, using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging model, revealed that the ethanol and n-butanol extracts of D. tripetala had better radical scavenging activity with IC50 values of 2.02 and 0.631 µg/mL for ethanol and n-butanol extracts, respectively.  The methanol and ethanol extracts of M. excelsa showed higher radical scavenging capacity with IC50 of 0.194 and 8.84 µg/mL compared to that of the ascorbic acid which had IC50 value of 4.60 µg/mL.Conclusion: The radical scavenging ability of the extracts could be attributed to the presence of flavonoids and phenolics.

scholarly journals Anthocyanin, Lutein, Polyphenol Contents and Antioxidant Activity of Black, Red and White Pigmented Rice Varieties

2017 ◽  
Vol 1 (1) ◽  
pp. 43 ◽  
Author(s):  
Saravanan Ponnappan ◽  
Arun Thangavel ◽  
Omprakash Sahu
Keyword(s):  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Anthocyanin Content ◽  
Black Rice ◽  
Rice Varieties ◽  
Pigmented Rice ◽  
Polyphenol Compound ◽  
Glutinous Rice ◽  
Scavenging Capacity ◽  
Radical Scavenging Ability

<p><em>Colour rice varieties are rich in antioxidants and functional based properties such as anthocyanin, lutein and phenolic compounds. In this experiment, two of red pigmented (TPS-1and TKM-9), one white (glutinous rice) and black pigmented rice varieties are cultivated from India were analysed to determine their antioxidants and nutrition based functional properties. Based on the result, the anthocyanin content was very high on black rice than other variety contents up to 244.45</em><em> </em><em>mg/100 g. Polyphenol compound were varied significantly within the compared varieties. Highest polyphenol compound content (463.05 mg/100</em><em> </em><em>g) was found in the black rice and also showed rich antioxidant properties. Obviously, black rice rich source of lutein compound was also higher than other varieties where under the experimental condition. DPPH (Determination of 2, 20-diphenyl-1picrylhydrazyl radical scavenging ability) scavenging capacity starting from 69.46% to 76.4% ranged to level of remain DPPH. </em></p>

scholarly journals Antioxidant Capacity and Free Radical Scavenging Effects on Nigerian Pineapple (Ananas cormosus) and Orange (Citrus sinensis) Pulp Extracts at Different Levels of Ripeness

2016 ◽  
Vol 3 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Stella Chintua Ortutu ◽  
Matthew Olaleke Aremu
Keyword(s):  
Lipid Oxidation ◽  
Antioxidant Capacity ◽  
Citrus Sinensis ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Maturation Stage ◽  
Hydrogen Atoms ◽  
Freeze Dried ◽  
Radical Scavenging Ability ◽  
Different Levels

Background: There is a need to shift interest from the use of synthetic antioxidants which are harmful to the use of natural antioxidants from fruits and vegetables for the prevention of lipid oxidation. Objective: The total polyphenols, flavonoids, lipid-soluble antioxidants (CALT) and radical scavenging ability of the pulp extracts of pineapple (Ananas cormosus) and orange (Citrus sinensis) were investigated at different maturation stages for the purpose of determining their antioxidant capacity and the possibility of using these fruits at every maturation stage for the prevention of lipid oxidation. Methods: The pulps of these fruits were extracted at different levels of ripeness; unripe (UR), about to ripe (AR) and ripe (RP). The extracted pulps were freeze-dried and used for the analysis. The total phenol content was determined by spectrophotometry (Folic Ciocalteu’s method) while 1, 1-diphenyl-2-picrylhydrazyl (DPPH) was used for the radical scavenging ability. The various antioxidant capacities were compared with standard antioxidants such as gallic acid, rutin, α-tocophenol and ascorbic acid. Results: The results showed that the two edible fruits investigated at different levels of ripeness possess high quality antioxidants (those that can scavenge free radicals, function as metal chelators or donate hydrogen atoms). Radical scavenging ability of the fruit pulps was significantly affected (P < 0.05) by the different level of ripeness. Conclusion: The unripe fruits had the highest antioxidant properties suggesting that the antioxidant capacity of the fruits decreased as the fruits ripened.

Dediazoniation of p-hydroxy and p-nitrobenzenediazonium ions in an aqueous medium: Interference by the chelating agent diethylenetriaminepentaacetic acid

2003 ◽  
Vol 81 (7) ◽  
pp. 832-839 ◽  
Author(s):  
B Quintero ◽  
M C Cabeza ◽  
M I Martínez ◽  
P Gutiérrez ◽  
P J Martínez
Keyword(s):  
Experimental Data ◽  
Aqueous Medium ◽  
Radical Scavenging ◽  
Chelating Agent ◽  
Diethylenetriaminepentaacetic Acid ◽  
Oh Groups ◽  
Metal Chelator ◽  
Radical Scavenging Capacity ◽  
Scavenging Capacity ◽  
Neutral Aqueous Medium

We have made a comparative study of the dediazoniation of p-hydroxy and p-nitrobenzenediazonium ions. The electron-withdrawing and donating properties of the -NO2 and -OH groups strongly determine the reactivity of both compounds, thus exerting different influences upon the dediazoniation reaction. We describe here how the decomposition of p-hydroxy and p-nitrobenzenediazonium ions in a neutral aqueous medium follows a different pattern in the presence of the metal-chelator diethylenetriaminepentaacetic acid (DTPA). The decomposition rate of p-hydroxybenzene diazonium decreases whilst the decomposition of the p-nitrobenzenediazonium ion is enhanced. The experimental data are discussed with reference to a common scheme of interference for both benzenediazonium ions in the light of the radical-scavenging capacity of DTPA.Key words: p-hydroxybenzenediazonium ion, p-nitrobenzenediazonium ion, di-ethylenetriaminepentaacetic acid, dediazoniation, radical scavenging, artifacts.

scholarly journals Investigation of Reaction Mechanisms and Kinetics of the Radical Scavenging Ability of 5-Tert-Butylbenzene-1,2,3-Triol and 3,5-di-Tert-Butylbenzene-1,2-Diol Compounds Towards OOH Radical

2018 ◽  
Vol 43 (2) ◽  
pp. 101-111
Author(s):  
Anes El-Hadj Saïd ◽  
Sidi Mohamed Mekelleche
Keyword(s):  
Gas Phase ◽  
Density Functional ◽  
Radical Scavenging Activity ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Hydrogen Atom Transfer ◽  
System A ◽  
Radical Adduct ◽  
Scavenging Capacity ◽  
Radical Scavenging Ability

The antioxidant properties of the synthesised 5- tert-butylbenzene-1,2,3-triol (system A) and the designed 3,5-di -tert-butylbenzene-1,2-diol (system B) have been explored through density functional theory at the M05-2X/6-31+G(d,p) level of theory. The quantum mechanics-based test for overall free radical scavenging activity (QM- ORSA) protocol has been employed to account for their radical-scavenging capacity against the hydroperoxyl radical (HOO•) in the gas phase and in toluene solvent as a mimic lipid medium. The different mechanisms of the chemical reactions of the studied systems with HOO• have been considered, namely (i) the hydrogen atom transfer (HAT), (ii) the single electron transfer followed by proton transfer and (iii) the radical adduct formation. Our calculations provide evidence that HAT is the most favoured reaction mechanism in both the gas phase and in lipid media and the calculated thermodynamic and kinetic parameters indicate that the designed compound is more efficient than the synthesised system A and the reference system (α-tocopherol).

scholarly journals Solving the lignin waste crisis: Utilization of lignin to produce value- added antioxidant agents: حل أزمة نفايات اللجنين: استخدام اللجنين لإنتاج مضادات أكسدة ذات قيمة مضافة

2021 ◽  
Vol 5 (4) ◽  
pp. 151-128
Author(s):  
Feras Mosleh Almowalad Feras Mosleh Almowalad
Keyword(s):  
Antioxidant Activity ◽  
Waste Product ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Value Added ◽  
Attractive Alternative ◽  
Hydrogen Atoms ◽  
Chemical Structures ◽  
Antioxidant Agents ◽  
Lower Temperature

  Lignin is a major component of biomass that is considered a huge energy and carbon reserve. Aside from being the second most abundant polymer in nature, it is a major by- product of pulping, paper and other forestry- based industries with about 70 million tons per year. Due to it being highly biologically recalcitrant, lignin is underutilized and considered a waste product that is solely incinerated for power generation. Establishment of a market for lignin- based, value- added chemicals was a necessity. Because of its renewable nature, availability, and richness in phenolic component, however, it is considered as an attractive alternative for antioxidant activity. In our research, all types of extracted lignin exhibited a value ranging from 2.21 to 11.47 on the AAI assay suggesting high antioxidant activity. Furthermore, special chemical structures such as hydrogen atoms, double bonds between side chain carbons, as well as the presence of methoxyl groups can increase antioxidant activity by 2- 3 folds via means of radical scavenging. Finally, lignin extracted at higher temperature (~95C and greater) exhibited higher ORAC values compared to lignin extracted at lower temperature; ORAC values of 1072.32 to 3119.68 versus 1741.72 to 1745.11, respectively. This paper is going to shed more light on the lignin antioxidant properties, where it stems from, what affects it, as well as future directions and possible interdisciplinary potential improvement.    

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