scholarly journals Antioxidant and Chemosensitizing Effects of Flavonoids with Hydroxy and/or Methoxy Groups and Structure-Activity Relationship

2007 ◽  
Vol 10 (4) ◽  
pp. 537 ◽  
Author(s):  
Ju-Mi Jeong ◽  
Cheol-Hee Choi ◽  
Su-Kyeong Kang ◽  
In-Hwa Lee ◽  
Ji-Yoon Lee ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Structure Activity Relationship ◽  
Activity Relationship ◽  
Oh Groups ◽  
Structure Activity ◽  
P Glycoprotein ◽  
Ic50 Values

Purpose. Flavonoids have been used as antioxidant, chemopreventive and chemosensitizing agents. In this study, eleven flavonoids containing a variety of hydroxy (OH) and/or methoxy (OMe) groups were evaluated for their antioxidant, cytotoxic and chemosensitizing effects to create a structure-activity relationship (SAR). Methods. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical solution-based chemical assay and and 2',7'-dichlorofluorescin diacetate (DCFH-DA) cellular-based assay were used to compare the free radical scavenging activity on the same molar concentration basis using the AML-2/DX100 cells which are characterized by the down-regulated expression of catalase and resulting supersensitiviy to hydrogen peroxide. The chemosensitization and cytotoxicity were determined by the MTT assay in the presence or absence of an anticancer drug using the P-glycoprotein-overexpressing AML-2 subline AML-2/D100 cells. Results. The antioxidant activity of the flavonoid (3,5,7,3’,4’-OH) was higher than that of the flavonoid (5,7,3’,4’-OH). Flavonoids substituted with the various number of OMe decreased antioxidant activity. Flavonoids with 7-OH or 5,7-OH groups have the highest cytotoxicity, and flavonoids with 5,7-OMe group intermediate cytotoxicity. The IC50 values of flavonoid (5,7-OMe, 3’,4’,5’-OMe) and flavonoid (5,7-OMe, 4’-OMe), 0.4 M and 1.4 M. The IC50 values of flavonoid (5,6,7-OMe, 3’,4’-OMe) and flavonoid (5,6,7-OMe, 3’,4’,5’-OMe), 3.2 uM and 0.9 M, respectively, and those of flavonoid (5,6,7-OMe, 3’,4’,5’-OMe) and flavonoid (5,7-OMe,3’,4’,5’-OMe) were 0.9 M and 0.4 M, respectively. Conclusions. These results suggest that flavonoids with 3-OH group play a positive role in antioxidant activities, flavonoids with 5-OH and/or 7-OH groups show the higher cytotoxicity, and flavonoids with 3’-OMe and/or 5’-OMe groups plays positive but 6-OMe groups negative roles in the P-glycoprotein (Pgp) inhibition. It is believed that these SAR results can be taken into account for the development of flavonoids with high therapeutic index.

scholarly journals Antioxidant Activity of 1’-Hydroxyethylnaphthazarins and their Derivatives

2017 ◽  
Vol 12 (12) ◽  
pp. 1934578X1701201
Author(s):  
Natalia K. Utkina ◽  
Natalia D. Pokhilo
Keyword(s):  
Antioxidant Activity ◽  
Radical Cation ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Structure Activity Relationship ◽  
Activity Relationship ◽  
Hydroxyl Group ◽  
Side Chains ◽  
Scavenging Activity ◽  
Structure Activity

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.

scholarly journals Identification of Six Flavonoids as Novel Cellular Antioxidants and Their Structure-Activity Relationship

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Qiang Zhang ◽  
Wenbo Yang ◽  
Jiechao Liu ◽  
Hui Liu ◽  
Zhenzhen Lv ◽  
...  
Keyword(s):  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Structure Activity Relationship ◽  
Absorption Capacity ◽  
Activity Relationship ◽  
Antioxidant Enzyme Activities ◽  
Structure Activity ◽  
Low Cytotoxicity ◽  
Cellular Antioxidants

This study is aimed at determining the relationship of flavonoid structures to their chemical and intracellular antioxidant activities. The antioxidant activities of 60 flavonoids were investigated by three different antioxidant assays, including 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, oxygen radical absorption capacity (ORAC), and cellular antioxidant activity (CAA) assays. The result showed 6 flavonoids as good cellular antioxidants evaluated for the first time. The cellular antioxidant activities of compounds 7-methoxy-quercetin, 3-O-methylquercetin, 8-hydroxy-kaempferol, quercetin-3-O-α-arabinofuranose, kaempferol-7-O-glucopyranoside, and luteolin6-C-glucoside were linked with the upregulation of antioxidant enzyme activities (superoxide dismutase, catalase, and glutathione peroxidase). A structure-activity relationship suggested that 2,3-double bond, 4-keto groups, 3′,4′-catechol structure, and 3-hydroxyl in the flavonoid skeleton played important roles in the antioxidant behavior. Furthermore, the cell proliferative assay revealed a low cytotoxicity for 3-O-methylquercetin. The present results provide valuable information for the dietary application of flavonoids with different structures for high antioxidant.

scholarly journals Structure-activity relationship and MM2 energy minimized conformational analysis of quercetin and its derivatives in the DPPH• radical scavenging capacity

BIBECHANA ◽  
2020 ◽  
Vol 17 ◽  
pp. 20-27
Author(s):  
Gan B Bajracharya ◽  
Mohan Paudel ◽  
Rajendra K. C. ◽  
Sajan L. Shyaula
Keyword(s):  
Antioxidant Activity ◽  
Methyl Ether ◽  
Radical Scavenging ◽  
Structure Activity Relationship ◽  
Activity Relationship ◽  
Dihedral Angles ◽  
Structure Activity ◽  
Scavenging Capacity ◽  
Ic50 Values ◽  
High Antioxidant Activity

Antioxidant activity of quercetin (1) and its derivatives (2-15) was evaluated by using DPPH assay and IC50 values were calculated. Dihedral angles α of C3-C2-C1’-C6’ chain and β of O1-C2-C-1’-C2’ chain between AC and B rings of these flavones were determined by using MM2 energy minimized structures. Structure-activity relationship study revealed that quercetin (1), quercetin-5-methyl ether (2), quercetin-3’-methyl ether (3) and quercetin-3’,5-dimethyl ether (4) displaying a high antioxidant activity (IC50 = 47.20-119.27 μM) possess similar dihedral angles (α 11.1-11.5º and β 6.3-6.6º). Mono- and/or di-methoxy substituent(s) at 3’ and 5 positions of the flavone are most suitable for the preservation of the antioxidant capacity while retaining conformational geometry. BIBECHANA 17 (2020) 19-26

scholarly journals CYTOTOXIC AND ANTIOXIDANT ACTIVITIES OF SECONDARY METABOLITES FROM PULICARIA UNDULATA

2016 ◽  
Vol 8 (9) ◽  
pp. 150 ◽  
Author(s):  
Taha A. Hussien ◽  
Sayed A. El-toumy ◽  
Hossam M. Hassan ◽  
Mona H. Hetta
Keyword(s):  
Antioxidant Activity ◽  
Secondary Metabolites ◽  
Antioxidant Activities ◽  
Structure Activity Relationship ◽  
Activity Relationship ◽  
Hep G2 ◽  
Structure Activity ◽  
Dpph Method ◽  
Mcf 7

<p><strong>Objective:</strong><strong> </strong>To evaluate the <em>in vitro</em> cytotoxicity, antioxidant activities and structure-activity relationship of secondary metabolites isolated from <em>Pulicaria undulata</em>.</p><p><strong>Methods: </strong>The methylene chloride-methanol (1:1) extract of the air-dried aerial parts of <em>Pulicaria undulata</em> was fractionated and separated to obtain the isolated compounds by different chromatographic techniques. Structures of the isolated compounds were determined on the basis of the extensive spectroscopic analysis, including 1D and 2D NMR and compared with the literature data. The crude extract and the isolated compounds were evaluated for <em>in vitro</em> antioxidant activity using the 2,2 diphenyl dipicryl hydrazine (DPPH) method and cytotoxic assay using human breast cancer (MCF-7) and hepatoma (Hep G2) cell line.</p><p><strong>Results: </strong>Nine secondary metabolites were isolated from <em>Pulicaria undulata</em> in this study. Of which two terpenoidal compounds; 8-epi-ivalbin and 11β, 13-dihydro-4H-xanthalongin 4-<em>O</em>-β-D-glucopyranoside firstly isolated from the genus <em>pulicaria</em> and three flavonoids; eupatolitin, 6-methoxykaempferol, and patulitrin firstly isolated from <em>P. undulata</em>. 6-methoxykaempferol (IC<sub>50</sub> 2.3 µg/ml) showed the most potent antioxidant activity. The highest cytotoxic effect against MCF-7 and Hep G2 cells was obtained with eupatolitin (IC<sub>50</sub> 27.6 and 23.5 µg/ml) respectively. The structure-activity relationship was also examined and the findings presented here showed that 3, 5, 7, 4' and 3, 5, 4', 5'-hydroxy flavonoids were potent antioxidant and has cytotoxic activity.</p><p><strong>Conclusion: </strong><em>Pulicaria undulata</em> is a promising medicinal plant, and our study tends to support the therapeutic value of this plant as antioxidant drug and in the treatment of cancer.</p>

Cytotoxic and antioxidant effects of methoxylated stilbene analogues on HepG2 hepatoma and Chang liver cells: Implications for structure activity relationship

2010 ◽  
Vol 30 (2) ◽  
pp. 138-144 ◽  
Author(s):  
AH Hasiah ◽  
AR Ghazali ◽  
JFF Weber ◽  
S. Velu ◽  
NF Thomas ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Activities ◽  
Structure Activity Relationship ◽  
Liver Cells ◽  
Activity Relationship ◽  
Hydroxyl Groups ◽  
Structure Activity ◽  
Total Antioxidant ◽  
Stilbene Analogues ◽  
Chang Liver

Stilbenes possess a variety of biological activities including chemopreventive activity. This study was conducted to evaluate the structural activity relationships of six methoxylated stilbene analogues with respect to their cytotoxic effects and antioxidant activities on HepG2 hepatoma and Chang liver cells. The cytotoxic and total antioxidant activities of six stilbene analogues were determined by MTT and Ferric Reducing Antioxidant Power (FRAP) assays, respectively. We found that the cis-methoxylated stilbene: (Z)-3,4,4'-trimethoxystilbene was the most potent and selective antiproliferative agent (IC50 89 µM) in HepG2 cells. For the total antioxidant activity, compounds possessing hydroxyl groups at the 4' position namely (E)-3-methoxy-4'-hydroxystilbene, (E)-3,5-dimethoxy-4'-hydroxystilbene (pterostilbene), (E)-4-methoxy-4'-hydroxystilbene showed the highest antioxidant activity. Structure activity relationship studies of these compounds demonstrated that the cytotoxic effect and antioxidant activities of the tested compounds in this study were structurally dependent.

scholarly journals Hepatotoxicity and antioxidant activity of some new N,N′-disubstituted benzimidazole-2-thiones, radical scavenging mechanism and structure-activity relationship

2018 ◽  
Vol 11 (3) ◽  
pp. 353-369 ◽  
Author(s):  
Neda O. Anastassova ◽  
Anelia Ts. Mavrova ◽  
Denitsa Y. Yancheva ◽  
Magdalena S. Kondeva-Burdina ◽  
Virginia I. Tzankova ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Radical Scavenging ◽  
Structure Activity Relationship ◽  
Activity Relationship ◽  
Structure Activity

Synthesis, radical scavenging activity and structure–activity relationship of uric acid analogs

MedChemComm ◽  
2013 ◽  
Vol 4 (3) ◽  
pp. 527 ◽  
Author(s):  
Daisuke Yasuda ◽  
Kyoko Takahashi ◽  
Tomohiro Kakinoki ◽  
Yoko Tanaka ◽  
Tomoyuki Ohe ◽  
...  
Keyword(s):  
Uric Acid ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Structure Activity Relationship ◽  
Activity Relationship ◽  
Scavenging Activity ◽  
Structure Activity ◽  
Relationship Of

scholarly journals Structure Activity Relationship, Drug Likeness and Evaluation of Antioxidant Activity of Some Mannich Bases of Dihydropyrimidinones

2019 ◽  
Vol 31 (8) ◽  
pp. 1767-1773
Author(s):  
Ravinder Mamidala ◽  
Solomon Raj S. Bhimathati ◽  
Aparna Vema
Keyword(s):  
Radical Scavenging Activity ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Structure Activity Relationship ◽  
Mannich Bases ◽  
Free Radical Scavenging ◽  
Activity Relationship ◽  
Chemical Parameters ◽  
Structure Activity ◽  
Physico Chemical

A series of 21 O- and N-Mannich bases of 3,4-dihydropyrimidinones (2a-j and 3a-k) were synthesized by using microwave irradiation technique by multi-component reaction in two steps. All the compounds were evaluated for their free radical scavenging activity by four methods. Structure activity relationship studies revealed that the compounds 2h, 2g, 3h and 3g exhibited profound antioxidant properties compared to standard ascorbic acid. Among O- and N-Mannich bases, N-Mannich bases were found to be more potent in scavenging free radicals. The correlation between structure and activities of these compounds with concern to drug likeliness profile and other physico-chemical parameters are portrayed and verified experimentally.

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