scholarly journals DPPH-Scavenging Activities and Structure-Activity Relationships of Phenolic Compounds

2010 ◽  
Vol 5 (11) ◽  
pp. 1934578X1000501 ◽  
Author(s):  
Cheng-Dong Zheng ◽  
Gang Li ◽  
Hu-Qiang Li ◽  
Xiao-Jing Xu ◽  
Jin-Ming Gao ◽  
...  

Thirty-eight phenolic compounds (including 31 flavonoids) were examined for their DPPH radical-scavenging activities, and structure-activity relationships were evaluated. Specifically, the presence of an Ortho-dihydroxyl structure in phenolics is largely responsible for their excellent antiradical activity. 3-Hydroxyl was also essential to generate a high radical-scavenging activity. An increasing number of hydroxyls on flavones with a 3′,4′-dihydroxyl basic structure, the presence of a third hydroxyl group at C-5′, a phloroglucinol structure, glycosylation and methylation of the hydroxyls, and some other hydroxyls, for example 5-, and 7-hydroxyl in ring A, decreased the radical-scavenging activities of flavonoids and other phenolics.

2011 ◽  
Vol 76 (4) ◽  
pp. 491-497 ◽  
Author(s):  
Iva Todorova ◽  
Daniela Batovska ◽  
Bistra Stamboliyska ◽  
Stoyan Parushev

Sixteen hydroxychalcones were synthesized in sufficient purity by the Claisen-Schmidt condensation between appropriate acetophenones and aryl aldehydes. All the compounds were evaluated for their ability to scavenge the stable free 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. Important structure-activity relationships were observed that strongly contribute to the knowledge for the design of DPPH radical scavenging chalcones. Relevant theoretical parameters were computed in an attempt to understand and explain the obtained experimental results.


Author(s):  
Jianmin Chen ◽  
Mengnan Ran ◽  
Meixia Wang ◽  
Xinying Liu ◽  
Siwan Liu ◽  
...  

Abstract The related structure-activity relationships (SARs) of cinnamic acid and its derivates have not been studied in details yet. Herein, anti-tyrosinase and antioxidant activities of 18 compounds were evaluated. The results demonstrated that the substituents on the phenyl ring of cinnamic acid led to the enhancement of the inhibition on monophenolase and the weakening of the inhibition on diphenolase. Among these tested compounds, 9 was firstly discovered as a tyrosinase inhibitor in a reversible competitive manner with IC50 value of 68.6 ± 4.2 μM. Docking results demonstrated 9 located into the catalytic center of tyrosinase. Antioxidant assay indicated that only one hydroxyl group on the phenyl ring was not enough to possess the radical scavenging activity, and the number of hydroxyl groups may be more important. This study will be helpful for development of new cinnamic acid derivates as tyrosinase inhibitors and antioxidants with higher efficacy.


2017 ◽  
Vol 12 (12) ◽  
pp. 1934578X1701201
Author(s):  
Natalia K. Utkina ◽  
Natalia D. Pokhilo

The ABTS•+ radical cation scavenging activity of known (2-5, 9, 10) and new (6-8) 1’-hydroxyethylnaphthazarins and their products of esterification and etherification was evaluated and a structure-activity relationship was studied. It was shown, that the structure of side chains does not affect the radical scavenging activity of 1’-hydroxyethylnaphthazarins and their derivatives. The presence of methoxyl groups on the naphthazarin core slightly enhanced the antioxidant activity of compounds compared with compounds without methoxyl groups. The presence of the additional hydroxyl group on the naphthazarin moiety of isonorlomazarin (5) and its derivative (6) is essential for the activity.


Author(s):  
Fadime Seyrekoğlu ◽  
Hasan Temiz

H. perforatum, which is widely used in traditional medicine due to its bioactive compounds was extracted with ethanol-water (3:7). The extract was encapsulated with maltodextrin and gum arabic in a spray dryer in order to protect the phenolic compounds in its structure. Different amounts of microcapsules were added to our traditional drink, i.e. ayran (drinking yoghurt). The total phenolic content and DPPH radical scavenging activity of the microcapsules, extract of HP, and ayran samples were determined. The amount of total phenolic compounds in the microcapsule provided a superior effect than the extract. The ayran samples were supplemented with 2%, 3%, 4%, 5% and 6% of H. perforatum (HP) microcapsules and it is observed that total phenolic content (TPC) and DPPH radical scavenging activity indicated an increase with concentration. TPC and DPPH activity were determined as 256.94 mg GAE / 100mL and 78.05% for 6% of HP microcapsules supplemented samples. As a result of the sensory analysis, ayran samples which supplemented with 4% of HS microcapsule gained the highest scores by the panellists and received more appreciation than the control group. According to sensory analysis, HP4 (ayran produced with 4% HP added microcapsule) sample was determined as the best sample, while the HP6 (Ayran produced with 6% HP added microcapsule) sample had the highest scores in terms of DPPH scavenging activity and TPC results. The overall results of this study revealed that 4% HP supplemented ayran can be produced with its increased health benefits and desirable properties. In this study, the use of H. perforatum microcapsules in ayran, its effect on antioxidant and phenolic components, the usage rates and acceptability of microcapsules were investigated.


2008 ◽  
Vol 3 (11) ◽  
pp. 1934578X0800301 ◽  
Author(s):  
Maria Carla Marcotullio ◽  
Gildas Norbert Oball-Mond Mwankie ◽  
Lina Cossignani ◽  
Bruno Tirillini ◽  
Rita Pagiotti

The chemical composition of Sarcodon imbricatus (L.:Fr) Karsten (Hydnaceae) was evaluated to assess it as source of nutrients and nutraceuticals. The analyzed mushroom contains ergosterol and ergosterol peroxide. S. imbricatus methanolic extract showed a moderate antiradical activity (measured by DPPH radical scavenging activity). The combination of bioactive compounds and rich nutritional composition (high contents in protein, low content in fat, and its content of unsaturated fatty acids) makes the mushroom a good food.


Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3618
Author(s):  
Ekaterina A. Yurchenko ◽  
Ekaterina S. Menchinskaya ◽  
Evgeny A. Pislyagin ◽  
Ekaterina A. Chingizova ◽  
Elena V. Girich ◽  
...  

The influence of p-terphenyl polyketides 1–3 from Aspergillus candidus KMM 4676 and cerebroside flavuside B (4) from Penicillium islandicum (=Talaromyces islandicus) against the effect of neurotoxins, rotenone and paraquat, on Neuro-2a cell viability by MTT and LDH release assays and intracellular ROS level, as well as DPPH radical scavenging activity, was investigated. Pre-incubation with compounds significantly diminished the ROS level in rotenone- and paraquat-treated cells. It was shown that the investigated polyketides 1–3 significantly increased the viability of rotenone- and paraquat-treated cells in two of the used assays but they affected only the viability of paraquat-treated cells in the LDH release assay. Flavuside B statistically increased the viability of paraquat-treated cells in both MTT and LDH release assays, however, it increased the viability of rotenone-treated cells in the LDH release assay. Structure–activity relationships for p-terphenyl derivatives, as well as possible mechanisms of cytoprotective action of all studied compounds, were discussed.


2020 ◽  
Vol 44 (6) ◽  
pp. 557-566
Author(s):  
Vilma KAŠKONIENĖ ◽  
Kristina BIMBIRAITĖ-SURVILIENĖ ◽  
Paulius KAŠKONAS ◽  
Nicola TISO ◽  
Laima ČESONIENĖ ◽  
...  

The aim of this study was to evaluate the impact of forest clear-cutting on the phenolic compounds and antiradical activity of Vaccinium myrtillus, Vaccinium vitis-idaea, and forest litter collected during the vegetation stages in 2 forests types (Pinetum vacciniosumand Pinetum vaccinio-myrtillosum). The Folin-Ciocalteu method, aluminum trichloride colorimetric assay, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) test were applied to perform the total phenolic content (TPC), total flavonoid content (TFC), and antiradical activity analyses of the extracts of the underground and aboveground parts of the plants and forest litter. The TPC content varied from 35.87 to 229.76 mg/g (expressed as rutin equivalents) and 120.03 to 309.64 mg/g in the aboveground extracts of V. myrtillus and V. vitis-idaea, respectively. Remarkably lower amounts of phenolic compounds were determined in the underground extracts of the tested shrubs. The TPC content in the forest litter ranged from 3.12 to 11.89 mg/g. The radical scavenging activity (RSA) varied from 3.12 to 434.68 mg/g; the lowest antiradical activity was determined in the underground extracts, while the highest was in the aboveground extracts of V. myrtillus. The TFC was dependent on the vegetation phase, forest type, and clear-cutting, and varied from 7.97 to 40.18 mg/g in the aboveground extracts of the tested plants. Flavonoids were not detected in the underground extracts of the samples or in the forest litter. The chemometric analysis revealed statistically significant trends of environmental impact on V. myrtillus and V. vitis-idaea at the different vegetation stages. Hypotheses testing showed that the TPC, TFC and RSA expressed statistically significant (α ≤ 0.05) changes in 68%, 60% and 71% of the tested samples after clear-cutting, respectively.


2012 ◽  
Vol 610-613 ◽  
pp. 72-80 ◽  
Author(s):  
De Jun Mei ◽  
Guo Ping Yu ◽  
An Min Sun

The rice bran protein (RBP) was then hydrolyzed with various proteases (papain, flavorzyme, neutrase, protamex, and trypsin) to prepare antioxidant peptides. The rice bran protein hydrolysates (RBPH) were assessed using method of DPPH radical scavenging ability. Hydrolysate prepared with papain and flavorzyme (activity ratio 1:1) was found to have the highest antioxidant activity (IC50=6.778±0.21 mg/ml). This hydrolysate was purified using ultrafiltration, RBPH-III (Mw<3KDa) had the highest DPPH and hydroxyl radical scavenging activity (IC50 value of 6.56±0.28, 5.43±0.22, respectively) and highest reducing power activity (1.02±0.18 at 4 mg/mL). Later, RBPH-III was fractionated by SP-SephadexC-25 cation-exchange column into six fractions (A–F), fraction F with the highest DPPH scavenging activity, was then separated by size exclusion chromatography on a SephadexG-25 into three major fractions (F1–F3). Fraction F2 exhibited the highest DPPH scavenging activity was choose to fractionate by reversed-phase high performance liquid chromatography (RP-HPLC), seven antioxidant peptides were isolated, The F2-5 peptide displayed the highest DPPH radical-scavenging activity (58.2±1.63%; at 250 μg/ml) among these peptides, the amino acids composition of F2-5 was determined, which might play an important role on its antioxidant activity. In addition, purified peptide did show remarkable inhibition rate on SGC-7901 cells proliferation, and it also revealed the dose-dependent relationship. The results of this study suggest that rice bran protein hydrolysates are good source of natural antioxidants.


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