scholarly journals Synthesis and antioxidant activity of 2-methylthio-pyrido[3,2-e][1,2,4] triazolo[1,5-a]pyrimidines

2019 ◽  
Vol 17 (1) ◽  
pp. 823-830 ◽  
Author(s):  
Hatem A. Abuelizz ◽  
Hanan A.A. Taie ◽  
Mohamed Marzouk ◽  
Rashad Al-Salahi

AbstractA series of 2-methylthio-pyrido-triazolopyrimidines (1-17) were prepared by the reaction of dimethyl-N-cyanoimidodithiocarbonate with hydrazinopyridine carboxylic acid as starting reactants. Their chemical structures were affirmed with HREI-MS, IR and NMR analyses. The target compounds (1-17) were evaluated for their antioxidant activity using 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging, ferric reduction antioxidant power (FRAP) and reducing power capability (RPC). The results revealed that some pyrido-triazolopyrimidines showed good activity as antioxidant agents, in particular, compounds 12 and 15 were found to possess good antioxidant activity. Butylated hydroxyl toluene (BHT) was used as reference drug.

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Nur Sumirah Mohd Dom ◽  
Nurshieren Yahaya ◽  
Zainah Adam ◽  
Nik Mohd Afizan Nik Abd. Rahman ◽  
Muhajir Hamid

The present study aimed to evaluate the potential of standardized methanolic extracts from seven Ficus deltoidea varieties in inhibiting the formation of AGEs, protein oxidation, and their antioxidant effects. The antiglycation activity was analyzed based on the inhibition of AGEs, fructosamine, and thiol groups level followed by the inhibition of protein carbonyl formation. The antioxidant activity (DPPH radical scavenging activity and reducing power assay) and total phenolic contents were evaluated. After 28 days of induction, all varieties of Ficus deltoidea extracts significantly restrained the formation of fluorescence AGEs by 4.55–5.14 fold. The extracts also reduced the fructosamine levels by 47.0–86.5%, increased the thiol group levels by 64.3–83.7%, and inhibited the formation of protein carbonyl by 1.36–1.76 fold. DPPH radical scavenging activity showed an IC50 value of 66.81–288.04 μg/ml and reducing power activity depicted at 0.02–0.24 μg/ml. The extent of phenolic compounds present in the extracts ranged from 70.90 to 299.78 mg·GAE/g. Apart from that, correlation studies between the activities were observed. This study revealed that seven varieties of Ficus deltoidea have the potential to inhibit AGEs formation and possess antioxidant activity that might be attributed to the presence of phenolic compounds.


2018 ◽  
Vol 10 (1) ◽  
pp. 44 ◽  
Author(s):  
Riza Shabrina ◽  
Berna Elya ◽  
Arikadia Noviani

Objective: This study aimed to fractionate the antioxidant activity of the ethyl acetate leaf extract and to characterize the most active fractionsaccording to compound groups.Methods: The ethyl acetate extract was fractionated with column chromatography using a gradient elution system. Fractions were first screenedqualitatively for antioxidant activity before active fractions were quantified with respect to in vitro antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay and the ferric-reducing antioxidant power (FRAP) assay. The compound groups were identifiedfollowing separation by thin-layer chromatography.Results: Fraction 11 exhibited the greatest DPPH radical-scavenging activity, with an IC50 value of 6.58 μg/mL, while the fraction with the greatestantioxidant activity according to the FRAP assay was fraction 10, with a ferric ion equivalent antioxidant activity value of 1015.34 μmol/g.Conclusion: Compound group identification revealed that Fractions 10 and 11 contained flavonoids, with two common to both fractions, whilefraction 10 also contained one specific flavonoid.


Molecules ◽  
2019 ◽  
Vol 24 (5) ◽  
pp. 971 ◽  
Author(s):  
Ingrida Tumosienė ◽  
Kristina Kantminienė ◽  
Ilona Jonuškienė ◽  
Artūras Peleckis ◽  
Sergey Belyakov ◽  
...  

A series of novel 1-(5-chloro-2-hydroxyphenyl)-5-oxopyrrolidine-3-carboxylic acid derivatives containing chloro, hydroxyl, isopropyl, nitro, nitroso, and amino substituents at benzene ring and 1-(5-chloro-2-hydroxyphenyl)-5-oxopyrrolidine-3-carbohydrazide derivatives bearing heterocyclic moieties were synthesized. Antioxidant activity of the synthesized compounds was screened by DPPH radical scavenging method and reducing power assay. A number of compounds were identified as potent antioxidants. Antioxidant activity of 1-(5-chloro-2-hydroxyphenyl)-4-(5-thioxo-4,5-dihydro-1,3,4-oxadiazol-2-yl)pyrrolidin-2-one has been tested to be 1.5 times higher than that of a well-known antioxidant ascorbic acid. 1-(5-Chloro-2-hydroxyphenyl)-4-(4-methyl-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-3-yl)pyrrolidin-2-one has shown 1.35 times higher antioxidant activity than that of vitamin C by DPPH radical scavenging method and optical density value of 1.149 in reducing power assay. The structure of 1-(5-chloro-2-hydroxyphenyl)-N-(1,3-dioxoisoindolin-2-yl)-5-oxopyrrolidine-3-carboxamide was unambiguously assigned by means of X-ray diffraction analysis data.


2015 ◽  
Vol 34 (04) ◽  
pp. 399
Author(s):  
Paini Sri Widyawati ◽  
Anita Maya Suteja ◽  
Thomas Indarto Putut Suseno ◽  
Pricilia Monica ◽  
William Saputrajaya ◽  
...  

Organic Rices, such as Jasmine variety white organic rice, Saodah variety red organic rice, and Java variety black organic rice, are many cultivated by farmer in Indonesia, especially Sleman area, DI Yogyakarta. The potency of three varieties of organic rice as antioxidant source hasn’t been studied. Therefore this research was done to know the effect of pigment color difference in three varieties of organic rice on antioxidant activity, especially 1,1-diphenyl-2- pycrylhydrazyl (DPPH) radical scavenging activity and ion reducing power. The results showed that Saodah variety red organic rice had the highest antioxidant potency because it had the highest total phenol and total flavonoid, 37.93 mg GAE/g sample dry base and 0.85 mg CE/g sample dry base, respectively. However Saodah variety red organic rice had total anthocyanin lower than that of Java variety black organic rice, 0.0025 mg/g sample dry base and 0.024 mg/g sample dry base, respectively. Anthocyanin compounds identified in three varieties of organic rice were cyanidine-3-glucoside at 32 minute time retention and peonidine -3-glucoside at 37 minute time retention. 1,1-diphenyl-2-pycrylhydrazyl (DPPH) radical scavenging activity and ion reducing power of Saodah variety red organic rice were the highest, 0.90 mg equivalent vitamin E/g sample dry base and 278.28 mg equivalent vitamin E/g sample dry base, respectively.Keywords: Pigment, organic rice, antioxidant activity ABSTRAKBeras organik, meliputi beras putih varietas Jasmine, merah varietas Saodah, dan hitam varietas Jawa, banyak dibudidayakan oleh masyarakat di Indonesia, terutama daerah Sleman, D.I. Yogyakarta. Potensi ketiga jenis beras tersebut sebagai sumber antioksidan belum banyak dikaji. Oleh karena itu penelitian ini dilakukan untuk mengetahui pengaruh perbedaan pigmen pada ketiga jenis beras organik tersebut terhadap aktivitas antioksidan, khususnya kemampuan menangkap radikal bebas 2,2-difenil-1-pikrilhidrasil (DPPH) dan mereduksi ion besi. Hasil menunjukkan bahwa beras organik merah varietas Saodah paling berpotensi sebagai sumber antioksidan. Hal ini ditunjukkan dengan total fenol dan total flavonoid beras merah tertinggi dibandingkan kedua beras yang lain, masing-masing sebesar 37,93 mg GAE/g sampel db dan 0,85 mg CE/g sampel db. Meskipun beras organik merah mempunyai total antosianin (0,0025 mg/g sampel db) lebih rendah dari beras organik hitam (0,024 mg/g sampel db). Jenis senyawa antosianin yang terdeteksi pada ketiga jenis organik ini adalah sianidin-3-glukosida yang terdeteksi pada waktu retensi 32 menit dan peonidin-3-glukosida dengan waktu retensi 37 menit. Kemampuan menangkap radikal bebas DPPH dan kemampuan mereduksi ion besi beras organik merah tertinggi, masing-masing sebesar 0,90 mg ekuivalen vit E/g sampel db dan278,28 mg ekuivalen vit E/g sampel db.Kata kunci: Pigmen, beras organik, aktivitas antioksidan  


Author(s):  
Bilge Taşkın ◽  
Neriman Bağdatlıoğlu

During conventional fermentation of milk into yogurt and kefir, changes of antioxidant capacities (DPPH radical scavenging, ferrous chelating, reducing power, hydrogen peroxide/ H2O2 scavenging activity) and total phenolic content were investigated. Both products showed greater phenolic content, DPPH radical scavenging, and reducing power activities than was the case of their unfermented milk forms. But they were unable to scavenge H2O2. Chelating ability of milk increased by yogurt fermentation but decreased by kefir fermentation. In general, antioxidative capacity of milk improved throughout conventional yogurt and kefir fermentations and ripening periods (except chelating ability for kefir and H2O2 scavenging). This study is valuable since it evaluates the antioxidant power of yogurt and kefir produced by traditional fermentation with 5 different antioxidative approaches. In face of rapidly rising consumer demand for safe, healthy, functional but natural foods, revealed results might strengthen importance of conventional fermentation process and highlight the antioxidative contributions of mentioned products


Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2476 ◽  
Author(s):  
Yangliu Xia ◽  
Chen Chen ◽  
Yong Liu ◽  
Guangbo Ge ◽  
Tongyi Dou ◽  
...  

In this study, daphnetin 1 was chosen as the lead compound, and C-3 or C-4-substituted daphnetins were designed and synthesized to explore the potential relationship between the antioxidant activities and the chemical structures of daphnetin derivatives. The antioxidant activities of the generated compounds were evaluated utilizing the free radical scavenging effect on 2,2′-diphenyl-1-picrylhydrazyl, 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulfonate) cation, and the ferric reducing power assays, and were then compared with those of the standard antioxidant Trolox. The results showed that the catechol group was the key pharmacophore for the antioxidant activity of the daphnetins. The introduction of an electron-withdrawing hydrophilic group at the C-4 position of daphnetin enhanced the antioxidative capacity, but this trend was not observed for C-3 substitution. In addition, introduction of a a hydrophobic phenyl group exerted negative effects on the antioxidant activity in both the C-3 and C-4 substitutions. Among all of the derivatives tested, the most powerful antioxidant was 4-carboxymethyl daphnetin (compound 9), for which the strongest antioxidant activity was observed in all of the assays. In addition, compound 9 also displayed strong pharmaceutical properties in the form of metabolic stability. To summarize, compound 9 holds great potential to be developed as an antioxidant agent with excellent antioxidant activity and proper pharmacokinetic behavior.


2018 ◽  
Vol 187 ◽  
pp. 02002
Author(s):  
Kittiya Kesornbuakao ◽  
Suksun Amornraksa ◽  
Malinee Sriariyanun ◽  
Suvaluk Asavasanti ◽  
Patchanee Yasurin

Nanoencapsulation of Centella asaitica (CA) crude chloroform extract seems to be an attractive approach that may improve drug bioavailability and drug delivery system. In the study, CA extract-loaded gelatin nanoparticles (CGNP) were developed by gelatin one-step and two-step desolvation methods, using three different ratios between CA crude chloroform extract and gelatin (1:2, 1:3, and 1:4 w/w). The antibacterial and antioxidants activities of CGNP and CA were compared. The antioxidant activity of CGNP and CA was evaluated by using DPPH radical scavenging assay and ferric reducing antioxidant power (FRAP) assay. Results showed an enhancement of CGNP antibacterial activity against food borne pathogen. The highest inhibition diameters and FRAP determined from CGNP prepared by one-step at 1:4 ratios (1.03±0.39 cm and 1.23±019 mmol Fe2+/mg dried weight, respectively). However, CGNP was no significant difference in DPPH radical scavenging activity compared to CA. These results provide useful information for developing effective nanoencapsulation of CA as effective natural ingredient.


2011 ◽  
Vol 233-235 ◽  
pp. 2849-2854
Author(s):  
Jie Bi ◽  
Qing Li Yang ◽  
Li Na Yu ◽  
Jie Sun ◽  
Chu Shu Zhang

In this article, the antioxidant activity of the crude extract from peanut hulls was tested with phosphomolybdenum complex method, the reduction of K3Fe(CN)6 and DPPH assay. The IC50 value for DPPH radical scavenging lied 14.86μg ml-1, and 28 μg mL-1 of PHF exhibited total antioxidant activity and reducing power which were comparable to that of the ascorbic acid standard at 52.41 and 15.41 μg mL-1, respectively.


2019 ◽  
Vol 14 (5) ◽  
pp. 1934578X1984977 ◽  
Author(s):  
Magdalena Woźniak ◽  
Lucyna Mrówczyńska ◽  
Agnieszka Waśkiewicz ◽  
Tomasz Rogoziński ◽  
Izabela Ratajczak

Propolis is a natural material collected by honeybees, containing bioactive compounds that exhibit biological activity. The aim of this study was to assess the chemical composition of Polish propolis extracted with two different concentrations of ethanol, namely 70% and 96%, and to evaluate their antioxidant activity depending on extraction conditions. Samples of Polish propolis were extracted with 70% and 96% ethanol in order to obtain the ethanolic propolis extracts EEP70 and EEP96, respectively. Concentrations of 10 flavonoids and 6 phenolic acids were determined using the UPLC-PDA-TQD system. The antioxidant properties were determined based on the DPPH· free radical scavenging activity, Fe3+ reducing power assay, and ferrous ions (Fe2+) chelating activity assays. Moreover, the effects of the propolis extracts on human red blood cell morphology , the selective permeability of their membrane, as well as on free radicals-induced hemolysis were also assessed. Qualitative and quantitative analyses of both propolis extracts indicated that 70% ethanolic extract contained higher amounts of phenolic compounds than 96% ethanolic extract. The levels of antioxidant activity indicated that both Polish propolis extracts exhibited a high and comparable antioxidant power. The concentration of ethanol used for extraction had no effect on the antioxidant potential of propolis. The presented results indicate that the extracts of Polish propolis are rich in phenolic compounds and are very effective as antioxidant agents. Therefore, they may be applied as a constituent of products used in phytotherapy regardless of the concentration of ethanol used in propolis extraction.


2012 ◽  
Vol 209-211 ◽  
pp. 2009-2012 ◽  
Author(s):  
Ming Xiu Wei ◽  
Lin Tang ◽  
Qing Li Yang ◽  
Li Na Yu

High temperature peanut meal was fermented by double strains with solid-stated fermentation, using fermented product dissolved in water and via membrane separate, then obtained four molecular weight distribution(MWD), which were 10kDa. Using four MWD fermentation peptides do experimenting, separated, that is hydroxyl radical-scavenging, DPPH radical-scavenging, reducing power and ferrous ion-chelating, and compared with GSH, it shown that the peptides of 3kDa~10kDa MWD fermentation peptides have the max antioxidant activity, the second was the percolator of >10kDa MWD fermentation peptides, then was the peptides of 1kDa~3kDa MWD fermentation peptides and <1kDa MWD fermentation peptides had the least activity.


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