scholarly journals Synthesis, Characterization, and the Antioxidant Activity of Carboxymethyl Chitosan Derivatives Containing Thiourea Salts

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1810 ◽  
Author(s):  
Xueqi Sun ◽  
Jingjing Zhang ◽  
Yuan Chen ◽  
Yingqi Mi ◽  
Wenqiang Tan ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Ir Spectra ◽  
13C Nmr ◽  
Superoxide Radical ◽  
Radical Scavenging ◽  
Carboxymethyl Chitosan ◽  
Dpph Radical ◽  
Natural Polymers ◽  
Chitosan Derivatives ◽  
Radical Scavenging Ability

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.

scholarly journals Effects of Prebiotics on Antioxidant Activity of Goat Milk Fermented by Lactobacillus plantarum L60

2017 ◽  
Vol 21 (2) ◽  
pp. 11-18 ◽  
Author(s):  
Guowei Shu ◽  
Yunxia He ◽  
Hongchang Wan ◽  
Yixin Hui ◽  
Hong Li
Keyword(s):  
Antioxidant Activity ◽  
Lactobacillus Plantarum ◽  
Theoretical Basis ◽  
Superoxide Radical ◽  
Radical Scavenging ◽  
Goat Milk ◽  
Dpph Radical ◽  
Dpph Radical Scavenging ◽  
Scavenging Rates

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.

scholarly journals EVALUATION OF IN VITRO ANTIOXIDANT ACTIVITY OF A MEDICINAL HERB, WEDELIA CHINENSIS (OSBECK) MERRILL.

2018 ◽  
Vol 11 (10) ◽  
pp. 433
Author(s):  
Rehana Banu H ◽  
Nagarajan N
Keyword(s):  
Antioxidant Activity ◽  
Superoxide Radical ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Scavenging Activity ◽  
Dpph Radical ◽  
Total Antioxidant ◽  
Dpph Radical Scavenging ◽  
In Vitro Antioxidant Activity

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.

Chromatographic fingerprint analysis, antioxidant properties, and inhibition of cholinergic enzymes (acetylcholinesterase and butyrylcholinesterase) of phenolic extracts from Irvingia gabonensis (Aubry-Lecomte ex O’Rorke) Baill bark

2018 ◽  
Vol 29 (2) ◽  
pp. 217-224 ◽  
Author(s):  
Oluwafemi Adeleke Ojo ◽  
Adebola Busola Ojo ◽  
Basiru Olaitan Ajiboye ◽  
Babatunji Emmanuel Oyinloye ◽  
Ayodele Jacob Akinyemi ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Stem Bark ◽  
Dependent Manner ◽  
Dpph Radical ◽  
Irvingia Gabonensis ◽  
Radical Scavenging Ability ◽  
Dpph Radical Scavenging ◽  
Phenolic Extracts

AbstractBackground:Irvingia gabonensisstem bark is a medicinal plant used in most parts of Africa to manage a number of ailments including neurodegenerative diseases that occur without scientific basis. This work characterized the phenolic composition, evaluated the cholinergic enzymes (acetylcholinesterase, AChE and butyrylcholinesterase, BChE) inhibition, and assessed the antioxidant activity of phenolic extracts fromI. gabonensis(Aubry-Lecomte ex O‘Rorke) Baill bark.Methods:Total phenol and flavonoids content was evaluated in addition to antioxidant activity as shown by Fe2+chelation, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ability, and 2,2-azino-bis-(3-ethylbenthiazoline-6-sulfonic acid) (ABTS) radical scavenging ability. Inhibitory activities on AChE and BChE were evaluated.Results:The extract was found to be rich in phenolic acid (ellagic acid) and flavonoids (quercetrin, kaempferol, and apigenin). The phenolic extracts displayed DPPH radical scavenging ability (IC50=19.98 μg/mL), ABTS radical scavenging ability (IC50=18.25 μg/mL), iron chelation (IC50=113.10 μg/mL), and reducing power (Fe3+to Fe2+) (5.94 mg ascorbic acid equivalent/100 g). Extracts ofI. gabonensisinhibited AChE (IC50=32.90 μg/mL) and BChE (IC50=41.50 μg/mL) activities in concentration-dependent manner.Conclusions:Hence, possible mechanism through which the stem bark executes their anti-Alzheimer’s disease activity might be by inhibiting cholinesterase activities in addition to suppressing oxidative-stress-induced neurodegeneration.

scholarly journals Structural Features of Sulfated Glucuronomannan Oligosaccharides and Their Antioxidant Activity

Marine Drugs ◽  
2018 ◽  
Vol 16 (9) ◽  
pp. 291 ◽  
Author(s):  
Weihua Jin ◽  
Langlang Ren ◽  
Bing Liu ◽  
Quanbin Zhang ◽  
Weihong Zhong
Keyword(s):  
Antioxidant Activity ◽  
Superoxide Radical ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Scavenging Activity ◽  
Dpph Radical ◽  
Dpph Radical Scavenging Activity ◽  
Hydroxyl Radical Scavenging Activity ◽  
Dpph Radical Scavenging

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.

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 ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Hydrogen Bond ◽  
Virtual Screening ◽  
Superoxide Radical ◽  
Radical Scavenging ◽  
Pharmacophore Model ◽  
Dpph Radical ◽  
Synthetic Compounds ◽  
Pharmacophore Modelling ◽  
Selection Of

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.

scholarly journals Conventional and Enzyme-Assisted Extraction of Rosemary Leaves (Rosmarinus officinalis L.): Toward a Greener Approach to High Added-Value Extracts

2021 ◽  
Vol 11 (8) ◽  
pp. 3724
Author(s):  
Antonella Rozaria Nefeli Pontillo ◽  
Lydia Papakosta-Tsigkri ◽  
Theopisti Lymperopoulou ◽  
Diomi Mamma ◽  
Dimitris Kekos ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Radical Scavenging ◽  
Extraction Methods ◽  
Added Value ◽  
Total Phenolic ◽  
Dpph Radical ◽  
Assisted Extraction ◽  
Radical Scavenging Ability ◽  
Dpph Radical Scavenging ◽  
Enzyme Assisted Extraction

The effect of different extraction methods of rosemary leaves on the total phenolic content (TPC), and the antioxidant activity of the extracts was herein investigated. Firstly, the solid-liquid conventional extraction (CEM) and microwave-assisted extraction (MAE) were implemented in an effort to identify the effect of the solvent and of microwave irradiation on the extract quality. The extract obtained from CEM at room temperature, using ethanol/water 95:5 v/v, showed the highest antioxidant activity (IC50 = 12.1 μg/mL). MAE using ethanol/water 50:50 v/v provided an extract with TPC and DPPH radical scavenging ability in a significantly shorter extraction time (1 h for MAE and 24 h for CEM). Enzyme-assisted extraction (EAE) using five commercial enzyme formulations was implemented, and the kinetic equation was calculated. Finally, the effect of EAE as a pretreatment method to CEM was examined. Pretreatment of the plant material with pectinolytic enzymes for 1 h prior to a 24 h CEM with 50% hydroethanolic solvent was found to be the optimum conditions for the extraction of rosemary leaves, providing an extract with higher DPPH radical scavenging ability (IC50 14.3 ± 0.8 μg/mL) and TPC (15.2 ± 0.3 mgGAE/grosemary) than the corresponding extract without the enzyme pretreatment.

scholarly journals Physicochemical Properties and Biological Activity of Active Films Based on Corn Peptide Incorporated Carboxymethyl Chitosan

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 604
Author(s):  
Liyan Wang ◽  
Liang Lei ◽  
Kang Wan ◽  
Yuan Fu ◽  
Hewen Hu
Keyword(s):  
Antioxidant Activity ◽  
Physicochemical Properties ◽  
Food Packaging ◽  
Biological Activities ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Carboxymethyl Chitosan ◽  
Vapor Permeability ◽  
Zone Method ◽  
Oil Resistance

Active films based on carboxymethyl chitosan incorporated corn peptide were developed, and the effect of the concentration of corn peptide on films was evaluated. Physicochemical properties of the films, including thickness, opacity, moisture content, color, mechanical properties, water vapor permeability, and oil resistance, were measured. Biological activities of the films, including the antioxidant and antibacterial activities, were characterized in terms of 2, 2-diphenyl-1-picrylhydrazyl free radical scavenging activity, reducing power, the total antioxidant activity, and the filter disc inhibition zone method. The results indicated that the incorporation of corn peptide caused interactions between carboxymethyl chitosan and corn peptide in Maillard reaction and gave rise to the films light yellow appearance. Compared with the Control, the degree of glycosylation, browning intensity, thickness, opacity, tensile strength, antioxidant activity, and antibacterial activity of films were increased, but the elongation, vapor permeability, and oil resistance of films were decreased. The films based on corn peptide and carboxymethyl chitosan can potentially be applied to food packaging.

scholarly journals Phytochemical, antioxidant and antimicrobial properties of Litsea angulata extracts

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 1839
Author(s):  
Harlinda Kuspradini ◽  
Indah Wulandari ◽  
Agmi Sinta Putri ◽  
Sabeti Yulis Tiya ◽  
Irawan Wijaya Kusuma
Keyword(s):  
Antimicrobial Activity ◽  
Antioxidant Activity ◽  
Radical Scavenging ◽  
Antimicrobial Properties ◽  
Phytochemical Analysis ◽  
Dpph Radical ◽  
Free Radical Formation ◽  
Dpph Radical Scavenging ◽  
Phytochemical Constituent ◽  
Microdilution Broth

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.

scholarly journals Antiglycation and Antioxidant Properties of Ficus deltoidea Varieties

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Nur Sumirah Mohd Dom ◽  
Nurshieren Yahaya ◽  
Zainah Adam ◽  
Nik Mohd Afizan Nik Abd. Rahman ◽  
Muhajir Hamid
Keyword(s):  
Antioxidant Activity ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Protein Carbonyl ◽  
Scavenging Activity ◽  
Dpph Radical ◽  
Dpph Radical Scavenging Activity ◽  
Ficus Deltoidea ◽  
Dpph Radical Scavenging

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.

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