scholarly journals Synthesis, Characterization, and Antioxidant Evaluation of Novel Pyridylurea-Functionalized Chitosan Derivatives

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 951 ◽  
Author(s):  
Jingjing Zhang ◽  
Wenqiang Tan ◽  
Lijie Wei ◽  
Fang Dong ◽  
Qing Li ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Structural Characteristics ◽  
Radical Scavenging ◽  
Cytotoxicity Test ◽  
Chitosan Derivatives ◽  
Ester Exchange ◽  
1H Nuclear Magnetic Resonance ◽  
Ft Ir ◽  
Ester Exchange Reaction

In order to improve the bioactivity of chitosan, we synthesized a novel series of chitosan derivatives: firstly, chitosan was reacted with methylclhlorofonmate obtaining N-methoxyformylated chitosan (1), which was then converted into N-pyridylurea chitosan derivatives (2a-2c) by amine-ester exchange reaction. In addition, N-pyridylurea chitosan derivatives were conducted by reacting with iodomethane to obtain quaternized N-pyridylurea chitosan derivatives (3a-3c). The structural characteristics of as-prepared chitosan derivatives were confirmed by fourier transform infrared (FT-IR), 1H nuclear magnetic resonance (1H NMR), elemental analysis, and scanning electron microscope (SEM). Meanwhile, the antioxidant activity of the chitosan derivatives was assessed in vitro. As shown in this paper, the antioxidant activity decreased in the order: c > b > a. Moreover, after the quaternization with iodomethane, quaternized N-pyridylurea chitosan derivatives immediately exhibited enhanced antioxidant capacity compared with N-pyridylurea chitosan derivatives. For example, in 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, the scavenging activities of 3a-3c were 91.75%, 93.63%, and 97.63% while 2a-2c were 42.32%, 42.97%, and 43.07% at 0.4 mg/mL. L929 cells were also adopted for cytotoxicity test of chitosan and synthesized derivatives by CCK-8 assay and all samples showed decreased cytotoxicity. These results suggested that the novel pyridylurea-functionalized chitosan derivatives could be an ideal biomaterial.

scholarly journals Microwave-Assisted Synthesis, Characterization, Antimicrobial and Antioxidant Activity of Some New Isatin Derivatives

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
G. Kiran ◽  
T. Maneshwar ◽  
Y. Rajeshwar ◽  
M. Sarangapani
Keyword(s):  
Antioxidant Activity ◽  
Free Radical ◽  
Radical Scavenging ◽  
Microwave Assisted Synthesis ◽  
Stable Free Radical ◽  
Ft Ir ◽  
Antimicrobial And Antioxidant Activity ◽  
New Compounds ◽  
Isatin Derivatives

A series of β-Isatin aldehyde-N,N′-thiocarbohydrazone derivatives were synthesized and assayed for theirin vitroantimicrobial and antioxidant activity. The new compounds were characterized based on spectral (FT-IR, NMR, MS) analyses. All the test compounds possessed a broad spectrum of activity having MIC values rangeing from 12.5 to 400 μg/ml against the tested microorganisms. Among the compounds3e,3jand3nshow highest significant antimicrobial activity. The free radical scavenging effects of the test compounds against stable free radical DPPH (α,α-diphenyl-β-picryl hydrazyl) and H2O2were measured spectrophotometrically. Compounds3j,3n,3l, and3e, respectively, had the most effective antioxidant activity against DPPH and H2O2scavenging activity.

scholarly journals Modification of Hydroxypropyltrimethyl Ammonium Chitosan with Organic Acid: Synthesis, Characterization, and Antioxidant Activity

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2460
Author(s):  
Yingqi Mi ◽  
Wenqiang Tan ◽  
Jingjing Zhang ◽  
Zhanyong Guo
Keyword(s):  
Antioxidant Activity ◽  
Organic Acids ◽  
Organic Acid ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Scavenging Activity ◽  
Chitosan Derivatives ◽  
13C Nuclear Magnetic Resonance ◽  
Wide Range

A novel and green method for the preparation of chitosan derivatives bearing organic acids was reported in this paper. In order to improve the antioxidant activity of chitosan, eight different hydroxypropyltrimethyl ammonium chitosan derivatives were successfully designed and synthesized via introducing of organic acids onto chitosan by mild and non-toxic ion exchange. The data of Fourier Transform Infrared (FTIR), 13C Nuclear Magnetic Resonance (NMR), 1H NMR, and elemental analysis for chitosan derivatives indicated the successful conjugation of organic acid salt with hydroxypropyltrimethyl ammonium chloride chitosan (HACC). Meanwhile, the antioxidant activity of the chitosan derivatives was evaluated in vitro. The results indicated that the chitosan derivatives possessed dramatic enhancements in DPPH-radical scavenging activity, superoxide-radical scavenging activity, hydroxyl radical scavenging ability, and reducing power. Furthermore, the cytotoxicity of the synthesized compounds was investigated in vitro on L929 cells and showed low cytotoxicity. Thus, the enhanced antioxidant property of all novel chitosan products might be a great advantage, while applied in a wide range of applications in the form of antioxidant in biomedical, food, and cosmetic industry.

scholarly journals Purification, characterization and antioxidant activities in vitro of polysaccharides from Amaranthus hybridus L.

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9077
Author(s):  
Zizhong Tang ◽  
Caixia Zhou ◽  
Yi Cai ◽  
Yujia Tang ◽  
Wenjun Sun ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Activities ◽  
Structural Characteristics ◽  
Radical Scavenging ◽  
Natural Antioxidants ◽  
Monosaccharide Composition ◽  
In Vitro Test ◽  
Amaranthus Hybridus ◽  
Total Antioxidant

Background Amaranthus hybridus L. is an annual, erect or less commonly ascending herb that is a member of the Amaranthaceae family. Polysaccharides extracted from traditional Chinese medicines may be effective substances with antioxidant activity. Methods In this study, we isolated crude polysaccharides from A. hybridus (AHP-M) using microwave-assisted extraction. Then, the AHP-M was purified by chromatography with DEAE-32 cellulose, and two fractions, AHP-M-1 and AHP-M-2, were obtained. The structural characteristics of AHP-M-1 and AHP-M-2 were investigated, and their antioxidant activities were analyzed in vitro. Results We found that the monosaccharide composition of AHP-M-1 was different from that of AHP-M-2. The molecular weights of AHP-M-1 and AHP-M-2 were 77.625 kDa and 93.325 kDa, respectively. The results showed that the antioxidant activity of AHP-M-2 was better than that of AHP-M-1. For AHP-M-2, the DPPH radical scavenging rate at a concentration of 2 mg/mL was 78.87%, the hydroxyl radical scavenging rate was 39.34%, the superoxide anion radical scavenging rate was 80.2%, and the reduction ability of Fe3+ was approximately 0.90. The total antioxidant capacity per milligram of AHP-M-2 was 6.42, which was higher than that of Vitamin C (Vc). Conclusion The in vitro test indicated that AHP-M-1 and AHP-M-2 have good antioxidant activity, demonstrating that A. hybridus L. polysaccharide has immense potential as a natural antioxidants.

scholarly journals Chemical Properties, Fatty-Acid Composition, and Antioxidant Activity of Goji Berry (Lycium barbarum L. and Lycium chinense Mill.) Fruits

Antioxidants ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 60 ◽  
Author(s):  
Prodromos Skenderidis ◽  
Dimitrios Lampakis ◽  
Ioannis Giavasis ◽  
Stefanos Leontopoulos ◽  
Konstantinos Petrotos ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Fatty Acid ◽  
Radical Scavenging ◽  
Attenuated Total Reflection ◽  
Lycium Chinense ◽  
Total Carbohydrate ◽  
Lycium Barbarum ◽  
Goji Berry ◽  
Ft Ir

In this study, the content composition and antioxidant activity of goji berry fruits from two species (Lycium barbarum and Lycium chinense) were assessed. The total carbohydrate and phenolic contents were evaluated using attenuated total reflection Fourier-transform infrared (ATR-FT-IR) spectroscopy, while the antioxidant activity of fruits was examined with two in vitro methods, which are based on the scavenging activity of the 2,2-diphenyl-1-picrylhydrazyl (DPPH•) and 2,2’-azino-bis(3-ethyl-benzthiazoline-sulfonic acid) (ABTS•+) free radicals. The fatty-acid profile was determined using gas chromatography coupled with mass spectrometry (GC-MS). The results of this study indicate that the fruits of L. barbarum present higher concentrations in carbohydrates and phenolics than L. chinense Mill. fruits. Furthermore, the antioxidant activity based on the half maximal inhibitory concentration (IC50) measurements of DPPH• and ABTS•+ free-radical scavenging was higher in L. barbarum than L. chinense Mill. Also, the GCMS analysis confirms the high levels of linoleic, palmitic, and oleic acids contained in the fruits of both species. Finally, the results of this study clearly show that the concentration of bioactive and antioxidant molecules is higher in L. barbarum than in L. chinense fruits, which was also confirmed by ATR-FT-IR measurements.

Curcumin-based antioxidant and glycohydrolase inhibitor compounds: Synthesis and in vitro appraisal of the dual activity against diabetes

2020 ◽  
Vol 16 ◽  
Author(s):  
Sajjad Esmaeili ◽  
Nazanin Ghobadi ◽  
Donya Nazari ◽  
Alireza Pourhossein ◽  
Hassan Rasouli ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Enzyme Inhibitor ◽  
Radical Scavenging Activity ◽  
Curcuma Longa ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Inhibitory Effect ◽  
Curcumin Derivatives ◽  
Reducing Power Assay

Background: Curcumin, as the substantial constituent of the turmeric plant (Curcuma longa), plays a significant role in the prevention of various diseases, including diabetes. It possesses ideal structure features as enzyme inhibitor, including a flexible backbone, hydrophobic nature, and several available hydrogen bond (H-bond) donors and acceptors. Objective: The present study aimed at synthesizing several novel curcumin derivatives and further evaluation of these compounds for possible antioxidant and anti-diabetic properties along with inhibitory effect against two carbohydrate-hydrolyzing enzymes, α-amylase and α-glucosidase, as these enzymes are therapeutic targets for attenuation of postprandial hyperglycemia. Methods: Therefore, curcumin-based pyrido[2,3-d]pyrimidine derivatives were synthesized and identified using an instrumental technique like NMR spectroscopy and then screened for antioxidant and enzyme inhibitory potential. Total antioxidant activity, reducing power assay and 1,1-diphenyl-2-picrylhydrazyl (DPPH• ) radical scavenging activity were done to appraisal the antioxidant potential of these compounds in vitro. Results: Compounds L6-L9 showed higher antioxidant activity while L4, L9, L12 and especially L8 exhibited the best selectivity index (lowest α-amylase/α-glucosidase inhibition ratio). Conclusion: These antioxidant inhibitors may be potential anti-diabetic drugs, not only to reduce glycemic index but also to limit the activity of the major reactive oxygen species (ROS) producing pathways.

Synthesis and antioxidant activity of new selenium-containing quinolines

2020 ◽  
Vol 16 ◽  
Author(s):  
Benedetta Bocchini ◽  
Bruna Goldani ◽  
Fernanda S.S. Sousa ◽  
Paloma T. Birmann ◽  
Cesar A. Brüning ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Superoxide Dismutase ◽  
Radical Scavenging ◽  
Building Blocks ◽  
Antioxidant Potential ◽  
In Vitro Assays ◽  
Pharmacological Activities ◽  
Antioxidant Power ◽  
Antioxidant Agents

Background: Quinoline derivatives have been attracted much attention in drug discovery and synthetic derivatives of these scaffolds present a range of pharmacological activities. Therefore, organoselenium compounds are valuable scaffolds in organic synthesis because their pharmacological activities and their use as versatile building blocks for regio-, chemio-and stereoselective reactions. Thus, the synthesis of selenium-containing quinolines has great significance, and their applicability range from simple antioxidant agents, to selective DNA-binding and photocleaving agents. Objective: In the present study we describe the synthesis and antioxidant activity in vitro of new 7-chloroN(arylselanyl)quinolin-4-amines 5 by the reaction of 4,7-dichloroquinoline 4 with (arylselanyl)-amines 3. Methods: For the synthesis of 7-chloro-N(arylselanyl)quinolin-4-amines 5, we performed the reaction of (arylselanyl)- amines 3 with 4,7-dichloroquinoline 4 in the presence of Et3N at 120 °C in a sealed tube. The antioxidant activities of the compounds 5 were evaluated by the following in vitro assays: 2,2- diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, 2,2-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), ferric ion reducing antioxidant power (FRAP), nitric oxide (NO) scavenging and superoxide dismutase-like activity (SOD-Like). Results: 7-Chloro-N(arylselanyl)quinolin-4-amines 5a-d has been synthesized in yields ranging from 68% to 82% by the reaction of 4,7-dichloroquinoline 4 with arylselanyl-amines 3a-d using Et3N as base, at 120 °C, in a sealed tube for 24 hours and tolerates different substituents, such as -OMe and -Cl, in the arylselanyl moiety. The obtained compounds 5a-d presented significant results with respect to the antioxidant potential, which had effect in the tests of inhibition of radical’s DPPH, ABTS+ and NO, as well as in the test that evaluates the capacity (FRAP) and in the superoxide dismutase-like activity assay (SOD-Like). It is worth mentioning that 7-chloro-N(arylselanyl)quinolin-4-amine 5b presented excellent results, demonstrating a better antioxidant capacity when compared to the others. Conclusion: According to the obtained results 7-chloro-N(arylselanyl)quinolin-4-amines 5 were synthesized in good yields by the reaction of 4,7-dichloroquinoline with arylselanyl-amines and tolerates different substituents in the arylselanyl moiety. The tested compounds presented significant antioxidant potential in the tests of inhibition of DPPH, ABTS+ and NO radicals, as well as in the FRAP and superoxide dismutase-like activity assays (SOD-Like).

scholarly journals Chemical Composition, In Vitro and In Silico Antioxidant Potential of Melissa officinalis subsp. officinalis Essential Oil

Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1081
Author(s):  
Matilda Rădulescu ◽  
Călin Jianu ◽  
Alexandra Teodora Lukinich-Gruia ◽  
Marius Mioc ◽  
Alexandra Mioc ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Chemical Composition ◽  
Essential Oil ◽  
In Silico ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Inhibitory Effect ◽  
Melissa Officinalis ◽  
Β Carotene

The investigation aimed to study the in vitro and in silico antioxidant properties of Melissa officinalis subsp. officinalis essential oil (MOEO). The chemical composition of MOEO was determined using GC–MS analysis. Among 36 compounds identified in MOEO, the main were beta-cubebene (27.66%), beta-caryophyllene (27.41%), alpha-cadinene (4.72%), caryophyllene oxide (4.09%), and alpha-cadinol (4.07%), respectively. In vitro antioxidant properties of MOEO have been studied in 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical scavenging, and inhibition of β-carotene bleaching assays. The half-maximal inhibitory concentration (IC50) for the radical scavenging abilities of ABTS and DPPH were 1.225 ± 0.011 μg/mL and 14.015 ± 0.027 μg/mL, respectively, demonstrating good antioxidant activity. Moreover, MOEO exhibited a strong inhibitory effect (94.031 ± 0.082%) in the β-carotene bleaching assay by neutralizing hydroperoxides, responsible for the oxidation of highly unsaturated β-carotene. Furthermore, molecular docking showed that the MOEO components could exert an in vitro antioxidant activity through xanthine oxidoreductase inhibition. The most active structures are minor MOEO components (approximately 6%), among which the highest affinity for the target protein belongs to carvacrol.

scholarly journals Inhibitory Effect of Antidesma bunius Fruit Extract on Carbohydrate Digestive Enzymes Activity and Protein Glycation In Vitro

Antioxidants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 32
Author(s):  
Pattamaporn Aksornchu ◽  
Netima Chamnansilpa ◽  
Sirichai Adisakwattana ◽  
Thavaree Thilavech ◽  
Charoonsri Choosak ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Radical Scavenging Activity ◽  
Digestive Enzyme ◽  
Radical Scavenging ◽  
Protein Glycation ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Fruit Extract ◽  
Antioxidant Power ◽  
Ic50 Values

Antidesma bunius (L.) spreng (Mamao) is widely distributed in Northeastern Thailand. Antidesma bunius has been reported to contain anthocyanins, which possess antioxidant and antihypertensive actions. However, the antidiabetic and antiglycation activity of Antidesma bunius fruit extract has not yet been reported. In this study, we investigated the inhibitory activity of anthocyanin-enriched fraction of Antidesma bunius fruit extract (ABE) against pancreatic α-amylase, intestinal α-glucosidase (maltase and sucrase), protein glycation, as well as antioxidant activity. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) chromatogram revealed that ABE contained phytochemical compounds such as cyanidin-3-glucoside, delphinidin-3-glucoside, ellagic acid, and myricetin-3-galactoside. ABE inhibited intestinal maltase and sucrase activity with the IC50 values of 0.76 ± 0.02 mg/mL and 1.33 ± 0.03 mg/mL, respectively. Furthermore, ABE (0.25 mg/mL) reduced the formation of fluorescent AGEs and the level of Nε-carboxymethyllysine (Nε-CML) in fructose and glucose-induced protein glycation during four weeks of incubation. During the glycation process, the protein carbonyl and β-amyloid cross structure were decreased by ABE (0.25 mg/mL). In addition, ABE exhibited antioxidant activity through DPPH radical scavenging activity and Trolox equivalent antioxidant capacity (TEAC) with the IC50 values 15.84 ± 0.06 µg/mL and 166.1 ± 2.40 µg/mL, respectively. Meanwhile, ferric reducing antioxidant power (FRAP) showed an EC50 value of 182.22 ± 0.64 µg/mL. The findings suggest that ABE may be a promising agent for inhibiting carbohydrate digestive enzyme activity, reducing monosaccharide-induced protein glycation, and antioxidant activity.

scholarly journals Honeybee Pollen Extracts Reduce Oxidative Stress and Steatosis in Hepatic Cells

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 6
Author(s):  
Juan Esteban Oyarzún ◽  
Marcelo E. Andia ◽  
Sergio Uribe ◽  
Paula Núñez Pizarro ◽  
Gabriel Núñez ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Phenolic Compounds ◽  
Cell Model ◽  
Radical Scavenging ◽  
Central Zone ◽  
Total Phenolic ◽  
Nonalcoholic Fatty Liver ◽  
Bee Pollen ◽  
Quercetin Concentration

Nonalcoholic fatty liver disease (NAFLD) is a major cause of morbidity and mortality worldwide. Additional therapies using functional foods and dietary supplements have been investigated and used in clinical practice, showing them to be beneficial. Honeybee pollen from Chile has shown a large concentration of phenolic compounds and high antioxidant activity. In this work, we characterized twenty-eight bee pollen extracts from the central zone of Chile according to botanical origin, phenolic profile, quercetin concentration, and antioxidant activity (FRAP and ORAC-FL). Our results show a statistically significant positive correlation between total phenolic content and antioxidant capacity. Selected samples were evaluated on the ability to reverse the steatosis in an in vitro cell model using Hepa1-6 cells. The pollen extracts protected Hepa1-6 cells against oxidative damage triggered by 2,2′-azo-bis(2-amidinopropane) dihydrochloride (AAPH)derived free radicals. This effect can be credited to the ability of the phenolic compounds present in the extract to protect the liver cells from chemical-induced injury, which might be correlated to their free radical scavenging potential. Additionally, bee pollen extracts reduce lipid accumulation in a cellular model of steatosis. In summary, our results support the antioxidant, hepatoprotective, and anti-steatosis effect of bee pollen in an in vitro model.

scholarly journals Optimization of sunflower head pectin extraction by ammonium oxalate and the effect of drying conditions on properties

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xuemei Ma ◽  
Jiayi Yu ◽  
Jing Jing ◽  
Qian Zhao ◽  
Liyong Ren ◽  
...  
Keyword(s):  
High Performance ◽  
Freeze Drying ◽  
Antioxidant Activities ◽  
Structural Characteristics ◽  
Radical Scavenging ◽  
Ammonium Oxalate ◽  
Extraction Process ◽  
Size Exclusion ◽  
Pharmaceutical Industries

AbstractPectin is a kind of natural and complex carbohydrates which is extensively used in food, chemical, cosmetic, and pharmaceutical industries. Fresh sunflower (Helianthus annuus L.) heads were utilized as a novel source of pectin extracted by ammonium oxalate. The conditions of the extraction process were optimized implementing the response surface methodology. Under optimal extraction parameters (extraction time 1.34 h, liquid–solid ratio 15:1 mL/g, ammonium oxalate concentration 0.76% (w/v)), the maximum experimental yield was 7.36%. The effect of spray-drying and freeze-drying on the physiochemical properties, structural characteristics, and antioxidant activities was investigated by FT-IR spectroscopy, high performance size exclusion chromatography, and X-ray diffraction. The results showed freeze-drying lead to decrease in galacturonic acid (GalA) content (76.2%), molecular weight (Mw 316 kDa), and crystallinity. The antioxidant activities of pectin were investigated utilizing the in-vitro DPPH and ABTS radical-scavenging systems. This study provided a novel and efficient extraction method of sunflower pectin, and confirmed that different drying processes had an effect on the structure and properties of pectin.

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