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 ◽  
...  

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.

2007 ◽  
Vol 10 (4) ◽  
pp. 537 ◽  
Author(s):  
Ju-Mi Jeong ◽  
Cheol-Hee Choi ◽  
Su-Kyeong Kang ◽  
In-Hwa Lee ◽  
Ji-Yoon Lee ◽  
...  

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.


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.


MedChemComm ◽  
2013 ◽  
Vol 4 (3) ◽  
pp. 527 ◽  
Author(s):  
Daisuke Yasuda ◽  
Kyoko Takahashi ◽  
Tomohiro Kakinoki ◽  
Yoko Tanaka ◽  
Tomoyuki Ohe ◽  
...  

2019 ◽  
Vol 31 (8) ◽  
pp. 1767-1773
Author(s):  
Ravinder Mamidala ◽  
Solomon Raj S. Bhimathati ◽  
Aparna Vema

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.


2021 ◽  
Vol 22 (2) ◽  
pp. 610
Author(s):  
Jana Hricovíniová ◽  
Zuzana Hricovíniová ◽  
Katarína Kozics

The evaluation of antioxidant compounds that counteract the mutagenic effects caused by the direct action of reactive oxygen species on DNA molecule is of considerable interest. Therefore, a series of 2,3-substituted quinazolinone derivatives (Q1–Q8) were investigated by different assays, and the relationship between their biological properties and chemical structure was examined. Genotoxicity and the potential DNA-protective effects of Q1–Q8 were evaluated by comet assay and DNA topology assay. Antioxidant activity was examined by DPPH-radical-scavenging, reducing-power, and total antioxidant status (TAS) assays. The cytotoxic effect of compounds was assessed in human renal epithelial cells (TH-1) and renal carcinoma cells (Caki-1) by MTT assay. Analysis of the structure–activity relationship disclosed significant differences in the activity depending on the substitution pattern. Derivatives Q5–Q8, bearing electron-donating moieties, were the most potent members of this series. Compounds were not genotoxic and considerably decreased the levels of DNA lesions induced by oxidants (H2O2, Fe2+ ions). Furthermore, compounds exhibited higher cytotoxicity in Caki-1 compared to that in TH-1 cells. Substantial antioxidant effect and DNA-protectivity along with the absence of genotoxicity suggested that the studied quinazolinones might represent potential model structures for the development of pharmacologically active agents.


2021 ◽  
Vol 6 (32) ◽  
pp. 8462-8470
Author(s):  
Chao Liu ◽  
Wen‐Zhu Wang ◽  
Meng‐Ting Song ◽  
Yao Lu ◽  
Ling‐Ling Qian ◽  
...  

Author(s):  
Taha A. Hussien ◽  
Sayed A. El-toumy ◽  
Hossam M. Hassan ◽  
Mona H. Hetta

<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>


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