scholarly journals Pharmacophore Modelling and Synthesis of Quinoline-3-Carbohydrazide as Antioxidants

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Mustapha El Bakkali ◽  
Lhassane Ismaili ◽  
Isabelle Tomassoli ◽  
Laurence Nicod ◽  
Marc Pudlo ◽  
...  

From well-known antioxidants agents, we developed a first pharmacophore model containing four common chemical features: one aromatic ring and three hydrogen bond acceptors. This model served as a template in virtual screening of Maybridge and NCI databases that resulted in selection of sixteen compounds. The selected compounds showed a good antioxidant activity measured by three chemical tests: DPPH radical, OH∘ radical, and superoxide radical scavenging. New synthetic compounds with a good correlation with the model were prepared, and some of them presented a good antioxidant activity.

2017 ◽  
Vol 21 (2) ◽  
pp. 11-18 ◽  
Author(s):  
Guowei Shu ◽  
Yunxia He ◽  
Hongchang Wan ◽  
Yixin Hui ◽  
Hong Li

AbstractThe production of functional fermented goat milk with synbiotic have attracted widespread attention recently with the purpose of promoting health. The aim of present study was to investigate the effects of several prebiotics (inulin, fructo-oligosaccharide, galacto-oligosaccharide and xylo-oligosaccharide) on antioxidant activity and promote the development of functional goat milk. All the prebiotics exhibited the potential of enhancing the antioxidant activity of fermented goat milk, especially inulin and fructo-oligosaccharide showed better promotive effects. The optimum additions of inulin, xylo-oligosaccharide, galacto-oligosaccharide and fructo-oligosaccharide obtained were 0.6%, 0.6%, 0.6% and 0.4%, respectively. The DPPH radical scavenging rates reached to 75.52%, 74.12%, 69.41%, 80.28%, respectively, and the scavenging rates of superoxide radical were 21.09%, 18.20%, 27.61% and 29.92%, respectively, which were all higher than the control. This paper provides theoretical basis for the development of the functional goat milk.


Author(s):  
Rehana Banu H ◽  
Nagarajan N

Objective: The objective is to evaluate the antioxidant activity of the methanolic leaf extract of Wedelia chinensis.Methods: In vitro antioxidant activity was evaluated by studying 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, superoxide radical scavenging activity, ferric reducing ability of plasma (FRAP) scavenging activity, hydroxyl radical scavenging activity, metal chelating activity, and total antioxidant activity. Ascorbic acid, BHT, quercetin, and EDTA were used as standards for the experiments.Results: Inhibition concentration50 values observed for DPPH radical scavenging, superoxide radical scavenging, and hydroxyl radical scavenging activities were determined to be 62.5, 769.23, and 617.28 μg/ml, respectively and that of FRAP scavenging, metal chelating, and total antioxidant activities were found to be 343 μmol Fe (II)/g, 79.56 mg EDTA/g extract, and 398.17 mg ascorbic acid eq/g extract, respectively.Conclusion: The results clearly indicate that methanolic leaf extract of the study species W. chinensis is effective in scavenging free radicals and has the potential to be a powerful antioxidant.


Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1810 ◽  
Author(s):  
Xueqi Sun ◽  
Jingjing Zhang ◽  
Yuan Chen ◽  
Yingqi Mi ◽  
Wenqiang Tan ◽  
...  

A new class of chitosan derivatives possessing thiourea salts were synthesized to improve the solubility and the antioxidant activity of chitosan. Firstly, chitosan was modified to carboxymethyl chitosan, combining carboxymethyl chitosan with thiourea salts that have different structures to form new chitosan derivatives. The chitosan and chitosan derivatives were characterized by FT-IR, 13C NMR, TGA, and elemental analyses. The new peaks of thiourea salts could be clearly observed at about 1240 cm–1 in the IR spectra, and the peak of C=S was clearly observed at around 180 ppm in the 13C NMR. IR spectra and 13C NMR of the structural units of these polymers validated the chitosan derivatives possessing thiourea salts were successfully synthesized. Their antioxidant properties were tested, including DPPH-radical scavenging ability, superoxide-radical scavenging ability, and hydroxyl-radical scavenging ability. Our results suggested the increase of thiourea salt groups in chitosan derivatives promotes the scavenging effect. The scavenging activity of 4TMCMCS, TMCMCS. 4,4DCMCS, and 4ACMCS against DPPH-radical and superoxide-radical were more than 90% at 1.6 mg/mL, respectively. In the cytotoxicity assay, no cytotoxicity was observed for the L929 cells with chitosan and its derivatives at all testing concentrations. These results demonstrated that the combination of chitosan and thiourea salt groups improved the antioxidant activity of chitosan, and the antioxidants or free radical scavengers based on natural polymers and thiourea salts showed potential applications.


Marine Drugs ◽  
2018 ◽  
Vol 16 (9) ◽  
pp. 291 ◽  
Author(s):  
Weihua Jin ◽  
Langlang Ren ◽  
Bing Liu ◽  
Quanbin Zhang ◽  
Weihong Zhong

Glucuronomannan oligosaccharides (Gs) were derived from fucoidan, which was extracted from the brown alga Sargassum thunbergii. Sulfated glucuronomannan oligosaccharides (SGs) were obtained by the sulfation of Gs. NMR techniques were used to reveal that the order of sulfation was Man-C6 > Man-C4 > Man-C1R > GlcA-C3 > Man-C3 > GlcA-C2. Finally, the antioxidant activities (hydroxyl radical scavenging activity, superoxide radical scavenging activity, reducing power and DPPH radical scavenging activity) of Gs and SGs were determined. The findings showed that the higher the degree of polymerization, the better the activity, except for the hydroxyl radical scavenging activity. In addition, the higher the sulfate content, the lower the activities for the reducing power and DPPH radical scavenging activity. Opposite results were found for the superoxide radical scavenging activity. Finally, compared with fucoidan, most Gs and SGs had higher antioxidant activity, suggesting that they might be good candidates for antioxidants.


F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 1839
Author(s):  
Harlinda Kuspradini ◽  
Indah Wulandari ◽  
Agmi Sinta Putri ◽  
Sabeti Yulis Tiya ◽  
Irawan Wijaya Kusuma

Background: Litsea angulata is a plant species belonging to Lauraceae family that is distributed throughout Indonesia, Malaysia, and New Guinea. The seeds have been traditionally used by local people in Kalimantan, Indonesia for the treatment of boils; however, there is no information about the potency of its branch, bark and leaves yet. This study aimed to determine the antioxidant, antimicrobial activity as well as the phytochemical constituent of Litsea angulata branch, bark, and leaves. Methods: Extraction was performed by successive maceration method using n-hexane, ethyl acetate, and ethanol solvent. Antioxidant activity was evaluated by DPPH radical scavenging assay. The antimicrobial activity using the 96 well-plate microdilution broth method against Staphylococcus aureus and Streptococcus mutans. Results: Based on the phytochemical analysis, it showed that extract of L. angulata contains alkaloids, flavonoids, tannins, terpenoids, and coumarin. The results showed that all extracts of plant samples displayed the ability to inhibit DPPH free radical formation and all tested microorganisms. Conclusions: L. angulata contains secondary metabolites such as alkaloids, flavonoids, tannins, terpenoids, carotenoids, and coumarin. The antioxidant activity on different plant extracts was a range as very strong to weak capacity. All extracts in this study could inhibit the growth of S. aureus and S. mutans.


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.


2013 ◽  
Vol 781-784 ◽  
pp. 1294-1297 ◽  
Author(s):  
Ping Liu ◽  
Yun Tao Gao ◽  
Jiao Jiao Yu ◽  
Jia Wei Cha ◽  
Dong Mei Zhao ◽  
...  

The UV-Vis absorption spectrum of kaempferol and DPPH was investigated, the optimum determination wavelength and reaction time for determining the DPPH radical scavenging activity of kaempferol was 517 nm and 30 min, respectively. Kaempferol exhibited strong DPPH radical scavenging activity with a IC50 value of 0.004349 mg·mL-1, which is smaller than that of rutin, indicating that kaempferol has a stronger antioxidant activity than rutin.


Author(s):  
Pranabendu Mitra ◽  
Venkatesh Meda ◽  
Rick Green

The main objective of this research was to compare the retention of antioxidant activity and total anthocyanin content of Saskatoon berries dried by freeze drying, microwave-vacuum drying, thin layer hot air drying and vacuum drying. Antioxidant activity of berry samples was determined by DPPH radical scavenging and ABTS radical scavenging, and the pH differential method was used to determine total anthocyanin content of the berry samples. The results showed that the freeze dried Saskatoon berries exhibited the highest retention of anthocyanin and antioxidant activity among the dried samples, followed by microwave-vacuum dried berries, thin layer hot air dried berries and vacuum dried berries. There were significant differences between the berry samples at P<0.05.  DPPH radical scavenging and ABTS radical scavenging were correlated linearly with an R2 value of 0.99 at P<0.05 showing their effectiveness for the determination of the antioxidant activity of the Saskatoon berries. However, the DPPH radical scavenging assay was more effective than the ABTS radical scavenging assay. The results also showed that antioxidant activity of the berries was highly correlated with the total anthocyanin content of the fruit. The reduction of anthocyanin in dried berry samples was linearly correlated with the reduction of DPPH radical scavenging with an R2 value of 0.97 at P<0.05 and, also, linearly correlated with the reduction of ABTS radical scavenging with an R2 value of 0.88 at P<0.05.


2010 ◽  
Vol 9 (3) ◽  
pp. 457-460 ◽  
Author(s):  
M. Taufik Ekaprasada ◽  
Hazli Nurdin ◽  
Sanusi Ibrahim ◽  
Dachriyanus Dachriyanus

An antioxidant compound has been isolated from the leaves of Toona sureni (Blume) Merr. The structure was determined to be methyl 3,4,5-trihydroxybenzoate (methyl gallate), based on UV-vis, FTIR, NMR and MS spectra. The isolated compound exhibited potent antioxidant activity in the α,α-diphenyl-β-picrylhydrazyl (DPPH) radical scavenging test, with IC50 value 1.02 μg/mL.   Keywords: antioxidant activity, methyl gallate, Toona sureni


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