scholarly journals Structure and Antioxidant Activity of Soy Protein Isolate-Dextran Conjugates Obtained by TiO2Photocatalysis

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Bei Jin ◽  
Xiaosong Zhou ◽  
Bing Li ◽  
Caiyan Chen ◽  
Xiaosa Zhang ◽  
...  

The aim of this study was to investigate the structural characteristics and antioxidant activities of soy protein isolate- (SPI-) dextran conjugates obtained by TiO2photocatalysis treatment. Results revealed that the UV-vis absorption and the fluorescence intensity increased as the photocatalytic power increased (P<0.05). Higher photocatalytic power could promote the extent of glycation and the formation of high molecular weight SPI-dextran conjugates, which were evidenced by free amino group content and sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis. The Fourier transform infrared (FT-IR) spectra suggested that the amide I, II, and III bands of SPI were altered by the glycation induced by TiO2photocatalysis. Moreover, significant changes of secondary structure occurred in SPI-dextran conjugates. Theα-helix,β-sheet,β-turns, and random coil were changed from approximately 10.6%, 37.9%, 12.9%, and 38.6% to 3.8%, 10.4%, 17.7%, and 68.8%, respectively, after treatment at photocatalytic power of 1000 W. In addition, SPI-dextran conjugates obtained by TiO2photocatalysis treatment exhibited high hydroxyl radical scavenging activity and possessed increased reducing power. All data indicated that TiO2photocatalysis was an efficient method for promoting protein-polysaccharide copolymerisation.

Marine Drugs ◽  
2019 ◽  
Vol 17 (4) ◽  
pp. 217 ◽  
Author(s):  
Chien Thang Doan ◽  
Thi Ngoc Tran ◽  
Van Bon Nguyen ◽  
Anh Dzung Nguyen ◽  
San-Lang Wang

Chitosanase has attracted great attention due to its potential applications in medicine, agriculture, and nutraceuticals. In this study, P. mucilaginosus TKU032, a bacterial strain isolated from Taiwanese soil, exhibited the highest chitosanase activity (0.53 U/mL) on medium containing shrimp heads as the sole carbon and nitrogen (C/N) source. Using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis, a chitosanase isolated from P. mucilaginosus TKU032 cultured on shrimp head medium was determined at approximately 59 kDa. The characterized chitosanase showed interesting properties with optimal temperature and thermal stability up to 70 °C. Three chitosan oligosaccharide (COS) fractions were isolated from hydrolyzed colloidal chitosan that was catalyzed by TKU032 chitosanase. Of these, fraction I showed the highest α-glucosidase inhibitor (aGI) activity (65.86% at 20 mg/mL); its inhibitory mechanism followed the mixed noncompetitive inhibition model. Fractions II and III exhibited strong 2,2-diphenyl1-picrylhydrazyl (DPPH) radical scavenging activity (79.00% at 12 mg/mL and 73.29% at 16 mg/mL, respectively). In summary, the COS fractions obtained by hydrolyzing colloidal chitosan with TKU032 chitosanase may have potential use in medical or nutraceutical fields due to their aGI and antioxidant activities.


2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Huan Wang ◽  
Xiaohong Tong ◽  
Yue Yuan ◽  
Xinhui Peng ◽  
Qiaozhi Zhang ◽  
...  

The use of enzyme-assisted aqueous extraction to extract soybean oil will produce soy protein hydrolysates (SPH) that have good antioxidant properties but are bitter and hygroscopic. To microencapsulate these hydrolysates, soy protein isolate/maltodextrin mixtures were used as the carrier. The effects of spray-drying and freeze-drying on the bitterness, hygroscopicity, and antioxidant properties were compared. The properties of different dried samples were compared using solubility, hygroscopicity, moisture content, water activity, flowability, and glass transition temperature (Tg). The results showed that the spray-drying was more effective than freeze-drying. Hygroscopicity was reduced to 18.2 g/100 g, and the Tg value was raised to 80.8°C. The morphology was analyzed using scanning electron microscopy, and the antioxidant properties of the samples were measured using the ABTS˙+ radical scavenging activity. The results showed that spray-dried SPH had more carrier masking, which weakened bitterness, reduced moisture absorption, and had no significant negative impact on its oxidation resistance, solubility, and flowability, and spray-drying after carrier encapsulation of SPH improved the recovery rate.


2009 ◽  
Vol 2009 ◽  
pp. 1-6 ◽  
Author(s):  
K. Nagendra Prasad ◽  
Jing Hao ◽  
Chun Yi ◽  
Dandan Zhang ◽  
Shengxiang Qiu ◽  
...  

Antioxidant activities of wampee peel extracts using five different solvents (ethanol, hexane, ethyl acetate, butanol and water) were determined by using in-vitro antioxidant models including total antioxidant capability, 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activity, reducing power, and superoxide scavenging activity. Ethyl acetate fraction (EAF) exhibited the highest antioxidant activity compared to other fractions, even higher than synthetic antioxidant butylated hydroxyl toluene (BHT). In addition, the EAF exhibited strong anticancer activities against human gastric carcinoma (SGC-7901), human hepatocellular liver carcinoma (HepG-2) and human lung adenocarcinoma (A-549) cancer cell lines, higher than cisplatin, a conventional anticancer drug. The total phenolic content of wampee fraction was positively correlated with the antioxidant activity. This is the first report on the antioxidant and anticancer activities of the wampee peel extract. Thus, wampee peel can be used potentially as a readily accessible source of natural antioxidants and a possible pharmaceutical supplement.


2021 ◽  
pp. 28-38
Author(s):  
Henry Bulama ◽  
Daniel Dahiru ◽  
Joshua Madu

Background: Cataract is a major cause of visual impairment and blindness around the world. This study evaluated the in vitro antioxidant and anti-cataract activities of Cnidoscolus aconitifolius leaves extract and fractions. Antioxidant activities were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azinobis (3-ethylbenzothiozoline-6-sulfonic acid) (ABTS), total reducing power, and hydrogen peroxide scavenging assays. Anti-cataract potential was evaluated in vitro using goat lenses divided into eight groups of different treatments and incubated in artificial aqueous humor at 37 °C for 72 hours. Glucose-induced opacity in the lenses was observed and biochemical indices quantified (catalase, Malondialdehyde (MDA) and total protein in the lens homogenate). Results: The crude extract and its fractions possess substantial antioxidant activities. The aqueous fraction exhibited the best DPPH radical scavenging activity (IC50 value 78.599 µg/ml); while the dichloromethane fraction exhibited the highest ABTS radical scavenging activity with IC50 66.68 µg/ml. The anti-cataract evaluation of crude and fractions at 250 μg/ml showed a significant increase (p<0.05) in the total protein and catalase activity compared to the cataract control group. The malonaldehyde level decreased significantly (p<0.05) in all the treated groups.


Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1163 ◽  
Author(s):  
Chien Thang Doan ◽  
Thi Ngoc Tran ◽  
Van Bon Nguyen ◽  
Trung Dung Tran ◽  
Anh Dzung Nguyen ◽  
...  

Chitosan oligosaccharide (COS) has become of great interest in recent years because of its worthy biological activities. This study aims to produce COS using the enzymatic method, and investigates Paenibacillus sp. TKU047, a chitinolytic-producing strain, in terms of its chitosanase productivity on several chitinous material-containing mediums from fishery process wastes. The highest amount of chitosanase was produced on the medium using 2% (w/v) squid pens powder (0.60 U/mL) as the single carbon and nitrogen (C/N) source. The molecular mass of TKU047 chitosanase, which could be the smallest one among chitinases/chitosanases from the Paenibacillus genus, was approximately 23 kDa according to the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) method. TKU047 chitosanase possessed the highest activity at 60 °C, pH 7, and toward chitosan solution with a higher degree of deacetylation (DDA) value. Additionally, the hydrolysis products of 98% DDA chitosan catalyzed by TKU047 chitosanase showed the degree of polymerization (DP) ranging from 2 to 9, suggesting that it was an endo-type activity chitosanase. The free radical scavenging activity of the obtained chitosan oligosaccharide (COS) was determined. The result showed that COS produced with Paenibacillus sp. TKU047 chitosanase expressed a higher 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity than that from the commercial COSs with maximum activity and IC50 values of 81.20% and 1.02 mg/mL; 18.63% and 15.37 mg/mL; and 15.96% and 15.16 mg/mL, respectively. As such, Paenibacillus sp. TKU047 may have potential use in converting squid pens waste to produce chitosanase as an enzyme for bio-activity COS preparation.


2013 ◽  
Vol 11 (2) ◽  
pp. 191-197 ◽  
Author(s):  
Ishrat Nimmi ◽  
Ismet Ara Jahan ◽  
M Hemayet Hossain ◽  
Mohammad Burhan Uddin ◽  
M Sohel Rana ◽  
...  

A comparative study of antioxidant properties on two varieties of Phyllanthus (Phyllanthus niruiri L. & Phyllanthus urinaria L. leaves) growing in Bangladesh was done in the present study. Five complimentary test methods namely DPPH free radical scavenging activity, reducing power assay, total antioxidant capacity, total phenolic and flavonoid contents determination were used for the evaluation of antioxidant properties of two species of Phyllanthus. In the present investigation for the evaluation of antioxidant activities the concentration is expressed by the ratio of crude sample per solvent volume instead of extract weight per solvent volume. Based on these concentrations the investigated P. niruri L. and P. urinaria L. leaves extracts exhibited significant results. At 2 mg/ml concentration DPPH radical scavenging capacity of the methanol extract of both the plants was found to show significant (>90%) activity which is comparable to Ascorbic acid and BHA. In case of reducing power tests for both the extract, the activity of P. urinaria is comparable to that of BHA and AA and that of P. niruiri is comparable to BHA. P. niruiri showed better antioxidant potential than that of P. urinaria based on the observed results of their corresponding methanol extract. DOI: http://dx.doi.org/10.3329/dujps.v11i2.14579 Dhaka Univ. J. Pharm. Sci. 11(2): 191-197, 2012 (December)


2014 ◽  
Vol 707 ◽  
pp. 149-153 ◽  
Author(s):  
Xiao Hu ◽  
Xian Qing Yang ◽  
Lai Hao Li ◽  
Yan Yan Wu ◽  
Wan Ling Lin ◽  
...  

Microalgae protein hydrolysates (MPH) were obtained by enzymatic hydrolysis of defatted microalgae meal using neutral protease. The protein recovery, degree of hydrolysis, and the antioxidant activities of the hydrolysates were investigated. The results demonstrated that hydrolysates prepared by neutral protease at 50 °C for 4 h exhibited the strongest antioxidant activity. Under these conditions, the 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical scavenging activity and the reducing power of the hydrolysates were 68.3%, 50.8% and 1.303, respectively.


Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1552
Author(s):  
Muhammad Arslan Ahmad ◽  
Rabia Javed ◽  
Muhammad Adeel ◽  
Muhammad Rizwan ◽  
Yuesuo Yang

This study addresses the favourable effects of drought stress imposed by polyethylene glycol (PEG) 6000 on the micropropagated shoots of Stevia rebaudiana. Various concentrations, i.e., 0, 0.5, 1, 2, and 4% of PEG 6000 were applied to the nodal shoot explants for four weeks, and the influence produced on shoots growth parameters, bioactive steviol glycosides (rebaudioside A and stevioside), and nonenzymatic antioxidant activities (total phenolic content (TPC), total flavonoid content (TFC), total antioxidant capacity (TAC), total reducing power (TRP) and 1,1-diphenyl-2-picrylhydrazyl(DPPH)-free radical scavenging activity (FRSA)) was elucidated. The significantly highest yield (92.4% direct shoot organogenesis) and secondary metabolites (2.94% Reb A, 2.52% ST, 95.3% DPPH-FRSA, 15.0% TPC, 13.0 µg/mg TFC, 22.3 µg/mg TAC, and 19.8 µg/mg TRP) production in response to abiotic stress elicitors was obtained in Murashige and Skoog (MS) medium treatment provided with 4% of PEG 6000. The overall trend was significant enhancement of growth dynamics and pharmaceutical compounds from control to 4% of PEG 6000 concentration as a defensive response against reactive oxygen species (ROS) produced in excess by water deficit. This is a very promising study to be employed in bioreactors to get markedly enhanced content of compounds of medicinal importance in the pharmaceutical market.


Author(s):  
Ji Hae Lee ◽  
Hyeonmi Ham ◽  
Min Young Kim ◽  
Jee Yeon Ko ◽  
Eun Yeong Sim ◽  
...  

The phenolic compounds and radical scavenging activity of ethanolic extracts of five adzuki beans were evaluate according to cultivar. The predominant phenolic acids in five cultivars of adzuki bean were (+)-catechin and gallic acid. Antioxidant capacities were determined using 2,2-diphenyl-1-picrylhydrazyl and 2,2-azinobis (3-ethylbenothiazoline-6-sulphonic acid) diammonium salt, and reducing power was positively enhanced according to the total polyphenolic content. In a cell-based assay, adzuki beans showed cytoprotective effects against oxidative stress induced by tert-butyl hydroperoxide and inhibitory effects on the production of reactive oxygen species, except for the cultivar Vigna angularis var. nipponensis cv. Whinnarae. In conclusion, (+)-catechin was the predominant phenolic compound found in adzuki beans, but there were differences according to the cultivar. Overall, the adzuki bean cultivars showed different antioxidant activities and cytoprotective effects according to the concentration and composition of phenolic compounds.


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