Radical-scavenging activity,ACE-inhibiting capability and identification of rapeseed albumin hydrolysate

Albumin derived from rapeseed was hydrolyzed sequentially using alcalase and flavorzyme to produce antioxidant peptides.To identify antioxidant peptides,rapeseed albumin hydrolysate(RAH)was fractionated using size exclusion chromatography(G-25).The antioxidant activity and angiotensin I-converting enzyme(ACE)inhibiting activity of rapeseed peptides(RSP)purified from RAH were evaluated.The results revealed that RSP-4 had the highest ABTS radical-scavenging activity(TEAC value=0.24)and ACE-inhibiting capacity(IC50=0.19 mg/mL)compared to other fractions.Moreover,RSP-4 was identified as PFDSYFVC(977 D)by electrospray ionization(ESI)mass spectrometry and tandem mass spectrometry(MS/MS).©2013 Beijing Academy of Food Sciences.Production and hosting by Elsevier B.V.All rights reserved.

Synthesis of Hydroxystilbene Derivatives and their Antioxidant Activity by DPPH Method

Five hydroxystilbene derivatives were synthesized and their structures were determined using high-resolution mass spectrometry, ^1H NMB, and IR. In this study, the antioxidant activities of eight hydroxystilbenes （five synthesized hydroxystilbene derivatives and three other compounds） were evaluated with the free radiced scavenging model 1,1-diphenyl-2-picrylhydraxyl. It was observed that there exists a very significant linear rehtionship between the reciprocal of the EC50 value of each of the compounds and the maximum wavelength of the ultraviolet absorption peaks, It is believed that this result will be helpful for the further synthesis of such antioxidants.

Constituents from Aerial Parts of Bidens ceruna L. and Their DPPH Radical Scavenging Activity

A new chalcone glycoside, butein-4-methoxyl-4′-O-（6＂-O-acetyl）-β-D-glucopyranoside（2）, along with seven known compounds, namely, quercitrin（1）, luteolin-7-O-β-D-glucopyranoside（3）, butein-4＇-O-β-D-glucopyranoside（4）, butein-4-methoxyl-4＇-O-β-D-glucopyranoside（5）, butin-7-O-β-D-glucopyranoside（6）, isoquercitrin（7）, and sulfurein（8） was isolated from aerial parts of Bidens ceruna L. Their structures were elucidated on the basis of spectroscopic studies. Compounds 1-8 were tested for their DPPH radical scavenging activity and, except compounds 2 and 5, other compounds showed scavenging activitv.

Ultrasonic-Assisted Extraction of Fucoxanthin from Marine Macroalga Padina australis:Optimization,Bioactivity,and Structural Characterization

Macroalgae serve as a potential feedstock for fucoxanthin extraction.Fucoxanthin,a bioactive pigment found in the chloroplasts of marine algae,exhibits significant pharmacological properties.As a member of the carotenoid family,fucoxanthin plays a crucial role in both the food and pharmaceutical industries.This research explores the effects of ultrasonics on the extraction of fucoxanthin from the marine macroalga Padina australis.In addition,various extraction techniques and the influence of solvents on the efficient separation of fucoxanthin from algae have been studied and compared.Using methanol,chloroform,and a combination of methanol and chloroform(1:1,v/v),conventional fucoxanthin extraction from Padina australis yielded 8.12 mg of fucoxanthin per gram of biomass.However,the ultrasonic-assisted extraction resulted in a significantly higher yield of 16.9 mg of fucoxanthin per gram of biomass,demonstrating that the use of ultrasonics enhances the extraction rate compared to conventional methods.Therefore,the efficient separation of fucoxanthin from Padina australis is highly dependent on ultrasonic-assisted extraction.The process conditions for the extraction were optimized to maximize the yield of fucoxanthin from seaweeds.The following parameters were selected for optimization studies:moisture content,particle size,mixing speed,extraction temperature,extraction duration,and solid-to-solvent ratio.The extracted fucoxanthin exhibited various biological activities,including antimicrobial and antioxidant properties,and its structure was elucidated through FTIR and NMR spectroscopy.Additionally,thin-layer chromatography of the crude algae extracts confirmed the presence of fucoxanthin in the marine algae.Given these findings,the optimized extraction process holds the potential for scaling up to large-scale fucoxanthin production.Fucoxanthin,as a potent pharmacological agent,offers promising applications in the treatment of various ailments.

HPLC-DPPH法评价雪松松针抗氧化活性成分

目的评价雪松松针抗氧化活性成分。方法以维生素C(VC)和没食子酸为阳性对照,采用高效液相色谱(HPLC)法测定1,1-二苯基-2-苦肼基(DPPH)溶液加入雪松松针抗氧化活性成分后DPPH峰面积的衰减情况,并通过计算DPPH自由基的清除率和半数抑制浓度(IC_(50)),来评价雪松松针3种有效部位及8个单体成分的抗氧化活性。采用Agilent Eclipse Plus-C_(18)(250 mm×4.6 mm,5μm)为色谱柱,乙腈-水(62∶38,V/V)为流动相;检测波长为517 nm;流速为1.0 mL/min;柱温为25℃;进样量为20μL。结果雪松松针各有效部位清除DPPH自由基活性的能力大小依次为总黄酮>总多酚>总木脂素,IC_(50)分别为76.10、100.50、115.40μg/mL。与阳性对照比较,除山柰酚-3-O-β-D-葡萄糖苷外,7个单体化合物清除DPPH自由基活性的能力大小依次为二氢杨梅素>金丝桃苷>原儿茶酸>没食子酸>阿魏酸>杨梅素>山柰酚-3-O-(6″-O-E-阿魏酰基)-β-D-吡喃葡萄糖苷>VC>异鼠李素,IC50分别为16.50、19.40、23.73、27.24、32.10、32.20、47.60、93.20、297.20μg/mL。结论建立了HPLC-DPPH法用于评价雪松松针抗氧化活性;雪松松针具有较强的抗氧化活性,其中有效部位总黄酮、总多酚及单体成分二氢杨梅素、金丝桃苷等是具有开发前景的纯天然抗氧化剂。

Estimation of total phenolic content,in-vitro antioxidant and anti-inflammatory activity of flowers of Moringa oleifera

Objective:To evaluate and compare the antioxidant potential and anti-inflammatory activity of ethanolic extract of flowers of Moringa oleifera(M.oleifera)grown in Oman.Methods:Flowers of M.oleiferawere collected in the month of December 2012 and identified by a botanist.Alcoholic extract of the dry pulverized flowers ofM.oleiferawere obtained by cold maceration method.The ethanolic flower extract was subjected to preliminary phytochemical screening as the reported methods.Folin-Ciocalteu reagent was used to estimate total phenolic content.DPPH was used to determinein-vitroantioxidant activity and anti-inflammatory activity of flowers was investigated by protein denaturation method.Results:Phytochemical analysis of extract showed presence of major classes of phytochemicals such as tannins,alkaloids,flavonoids,cardiac glycosidesetc.M.oleiferaflowers were found to contain 19.31 mg/g of gallic acid equivalent of total phenolics in dry extract but exhibited moderate antioxidant activity.The anti-inflammatory activity of plant extract was significant and comparable with the standard drug diclofenac sodium.Conclusions:The results of our study suggest that flowers ofM.oleiferapossess potent anti-inflammatory activity and are also a good source of natural antioxidants.Further study is needed to identify the chemical compounds responsible for their anti-inflammatory activity.

STUDIES ON FREE RADICAL SCAVENGING ACTIVITY IN CHINESE SEAWEEDS PART I. SCREENING RESULTS

Antioxidants have attracted the attention of researchers due to their beneficial effects as free radical scavengers. Application of a stable free radical named 1,1 diphenyl 2 picrylhydrazyl(DPPH) to screen the free radical scavenging activity in 27 species of Chinese seaweed showed that 15 of them had significant activity in at least one of the organic solvent extracts. The most interesting seaweed species were Gelidium amansii, Gloiosiphonia capillaris, Polysiphonia urceolata, Sargassum kjellmanianum, Desmarestia viridis, and Rhodomela teres.

In vitro antibacterial and free radical scavenging activity of green hull of Juglans regia

Abstract Antioxidant supplements from plants are vital to count the oxidative damage in cells. We assessed the antioxidants and antibacterial activity of green hull of Juglans regia in this study. According to our results the maximum antibacterial activity was observed in ethanolic extract when compared to other extract. So, the ethanolic extract was studied for antioxidant activity which exhibited high antiradical activity against DPPH, hydroxyl, and nitric oxide radicals. In conclusion, green hull of J. regia showed strong reducing power activity and total antioxidant capacity. The results justify the therapeutic application of plant in the indigenous system of medicine.

Antioxidant activity and free radical scavenging activities of Streptomyces sp.strain MJM 10778

Objective:To investigate the antioxidant activity of soil-borne aetinobacteria.Methods:The total phenolic contents,the level of antioxidant potential by DPPH radical scavenging activity,MO scavenging activity,and ABTS radical scavenging activity in ethyl acelale extract were determined.Results:The 16 S rDNA sequencing analysis revealed that Streptomyces sp.strain MJM 10778.which was isolated from Hambak Mountain.Korea,has 99.9% similarity to Streptomyces misionensis(S.misionenis) NBRC 13063.The physiological and the morphological test revealed that the strain MJM 10778 has different characteristics from the strain NBRC.13063.The entire antioxidant assay with the ethyl acelale extract displayed good radical scavenging activity.The IC_(50) values of the strain MJM 10778 extract on DPPH,.NO.and ABTS radicals were identified to he 92.8 μg/mL,0.02 μg/ml,and 134.9 μg/mL,respectively.The ethyl acetate extract of the strain MJM 10778 showed an 81.500% of cell viability at 100 μg/mL in Raw264.7cell viability assay.Conclusions:The results obtained suggesl that the ethyl acetate extract of Streptomyces sp.strain MJM 10778 could be considered as a potential source of drug for the diseases that is caused by free radicals with its anti-oxidant activities and low cytotoxicity.

Antioxidant Activity of Pigment Extracted from Green-Wheat-Bran

The anthocyanin pigment extracted from green-wheat-bran was studied to identify its antioxidant activity.The antioxidant activities of the pigment were evaluated by anti-lipid peroxidation,total antioxidant activity （TAA）,superoxide anion radical scavenging activity （SARSA）,active oxygen scavenging activity （AOSA）,and DPPH （1,1-diphenyl-2 picrylhydrazyl free radical） radical scavenging activity.The results showed that the pigment had higher antioxidant activity and TAA,SARSA,AOSA and DPPH.scavenging activities at a certain concentration than Vc （antiscorbutic vitamin,vitamin C）,and the capacity increased with the increase of pigment concentration.Its TAA was 51.06 U mL-1,1.73 times of Vc,and SARSA 18 025.21 U mL-1,2.26% higher than Vc,and AOSA 3 776.31 U mL-1,1.24 times of Vc.As to the DPPH.scavenging activity of the pigment,there was a trend that higher concentration performed higher activity significantly improved with the company of Vc.The pigment showed significant antioxidant activities evaluated by different assays.Results will provide a better understanding on antioxidant activity of green wheat and allow the screening or breeding of green wheat varieties with higher antioxidant activity for food processing.

Antioxidant Activity Determination of Citronellal and Crude Extracts of <i>Cymbopogon citratus</i>by 3 Different Methods

Cymbopogon citratus, better known as lemongrass, is a plant commonly used for culinary purposes. It is known to contain the compound citronellal, which is responsible for the lemon-scent of many of the plants of the genus Cymbopogon. A chloroform extract of Cymbopogon citratus was screened to determine its free radical scavenging activities. Three different methods were used to test the antioxidant activity of the extract, including FRAP assay (Ferric reducing antioxidant potential), DPPH radical scavenging assay (1,1-diphenyl-2-picryl hydrazyl radical reducing power methods), and β-carotene bleaching assay. Cymbopogon citratus showed low radical scavenging activities compared to ascorbic acid, gallic acid and quercetin. The results obtained suggest that Cymbopogon citratus is best appreciated for its refreshing aroma and delicate taste, but has little to offer as a source of antioxidants.

Chemical Composition, Phenolics, Anthocyanins Concentration and Antioxidant Activity of Ten Wild Edible Plants

Plants were collected and prepared for chemical analysis, total phenolics, anthocyanins concentrations, and free radical scavenging activity. Results showed that, protein concentration of Malva parviflora (22.9%) was the highest among the plants. Ruta chalepensis had high levels of fat and carbohydrates (4.2% and 51.7%, respectively), but had the lowest level of ash (8.7%). Mineral concentrations varied and found to have appreciable amounts of Ca, Na, K, Cu, Fe, Mg, Mn, Zn and P. Total phenolic ranged from 163.1 (Tetragonolobus palaestinus) to 1328.8 mg GAE/100g (Ruta chalepensis). Anthocyanins ranged between 18.1 (Gundelia tournefortii) and 100.1 mg/100g (Rumex acetosella). These plants differed in free radical scavenging activity. It was concluded that these plants could be considered as natural sources for antioxidants and valuable natural resources as a new addition to the diet of inhabitants.

Phytochemical composition and in vitro antioxidant activity of aqueous extract of Aerva lanata(L.) Juss.ex Schult.Stem(Amaranthaceae)

Objective:To analyze the phytochemical composition and in vitro antioxidant properties of aqueous extract of Aerva Lanata（A.lanata） stem.Methods:During the preliminary phytochemical analysis,the aqueous extract of A.Ianata was screened for the presence of carbohydrates,proteins,phenolic compounds,oil and fats,saponins,flavonoids,alkaloids. tannins and phytosterols.Antioxidant activity of the extract was determined by 2.2-dipbenyl- 1-picrylhydrazyl radical scavenging activity,metal chelating activity,reducing power activity and DNA damage inhibition activity.Analysis of phenolic compounds was performed by FolinCiocaiteau reagent method and gradient high performance liquid chromatography technique. Results:Preliminary phytochemical analysis exhibited the presence of phenolic compounds, saponins.flavonoids.tannins and phytosterols as major phytochemical groups.The extract exhibited high 2.2—diphenyl-1-picrylhydrazyl radical scavenging activity(IC50= 110.74μg/ mL).metal chelating activity(IC50= 758.17μg/mL).reducing power activity and DIA damage inhibition efficiency.The extract was reported to possess a high amount of total phenolic content and some of them were identified as gallic acid（3,4,3-OH）,apigenin-7—O-glucoside tapigetrin), quercetin-3—O-rutinoside（rutin） and myricetin（3,5,7,3,4,5-OH）by high performance liquid chromatography analysis.The extract was found non toxic towards human erythrocytes in the hemolytic assay(IC50= 24.89 mg/mL).Conclusions:These results conclud that A.lanata stem possesses high antioxidant activity and can he used for the development of natural and sale antioxidant compounds.

Radical scavenging and antibacterial activity of Arnebia benthamii methanol extract

Objective:To evaluate in vitro antioxidant and antibacterial activity of methanolic extract of Arnebia benthamii（A.benthamii） whole plant.Methods:Plasmid damage was analyzed by agarose gell electrophoresis.Calf thymus DNA was monitored by TBARS formation.DPPH, reducing power and lipid peroxidation was evaluated by using standard procedures.Antibacterial assay was monitored by disc diffusion method.Results:DPPH radical scavenging and hydroxyl radical scavenging potential of the plant revealed that the extract to be active radical scavenger.Reducing(Fe3+-Fe2+) power and lipid peroxidation inhibition efficiency（TBARS assay） of the extract was also evaluated and the extract showed promising activity in preventing lipid peroxidation and might prevent oxidative damages to biomolecules.The extract offered a significant protection against plasmid and calf thymus UNA damage induced by hydroxyl radicals. The extract was also evaluated on different bacterial strains and the maximum antibacterial activity was exhibited against Escherichia coli（E.coli） when compared with standard drug. Conclusions:These findings demonstrate that the methanol extract of A.benthamii has excellent anti-oxidant activities and could be considered as a potential source of lead molecules for pharmaceutical industries.

Antioxidant activity of polyaniline nanofibers

Well-confined uniform polyaniline （PANI） nanofibers were synthesized by using photo-assisted chemical oxidative polymer- ization of aniline in the presence of different dopant acids, and the radical scavenging ability of the produced PANI nanofibers was determined by the DPPH assay. It was found that the antioxidant activity of PANI nanofibers was higher than conventional PANI, and increased with decreasing of averaged diameter of the nanofibers. The enhanced antioxidant activity was concerned with increased surface area of PANI nanofibers.

Antioxidant Activity of Different Solvent Extracts of Blumea Megacephala in Vitro

[Objectives] The aim was to study the antioxidant activity of different solvent extracts of Blumea Megacephala in vitro. [Methods] The removal rates of DPPH free radicals and ABTS free radicals and the reduction capacity of Fe^(3+) by ethanol extract( EE),acetone extract( AE) and ethyl acetate extract( EAE) of Blumea Megacephala were detected. [Results]The three extracts of Blumea Megacephala had certain antioxidant activity,of which the antioxidant activity of ethyl acetate extract was the strongest and has great potential for development.[Conclusions]The study can provide scientific reference for the deep research on the antioxidant activity of Blumea Megacephala.

Syntheses and Crystal Structures of [Na(H_2O)_(1/2)]X and NH_2(CH_2CH_3)_2X and Antioxidant Activity of the Former

In order to enhance the water-solubility and biological utilization rate of chrysin, sodium 5,7-dihydroxylflavone-8-sulfonate （1, [Na（H2O）1/2]X, X = C15H9OSO3, 5,7-dihydroxylfla- vone-8-sulfonate） was synthesized and its structure was identified on the basis of NMR, FT-IR and elemental analysis. The assembly of 5,7-dihydroxylflavone-8-sulfonate with diethylamide cation afforded diethylamide 5,7-dihydroxylflavone-8-sulfonate （2, NH2（CH2CH3）2X） which was characterized by FT-IR and elemental analysis. The crystal structures of 1 and 2 were determined by X-ray single-crystal diffraction analysis. The crystal of 1 is of triclinic system, space group P1, with a = 8.5628（13）, b = 12.8916（19）, c = 13.562（2） A, α = 82.494（1）, β = 78.601（2）, γ = 84.033（2）°, C30H20Na2O15S2, Z = 2, Mr = 730.59, V = 1450.3（4） A3, Dc = 1.673 g/cm3, F（000） = 748, p = 0.295 mm^-1, the final R = 0.0641 and wR = 0.1458. The crystal of 2 crystallizes in the triclinic system, space group Pi, with a = 7.689（2）, b = 11.184（3）, c = 11.734（3） A, α = 74.268（3）, βl = 81.751（4）, γ= 87.991（3）°, C19H21NO7S, Z = 2, Mr= 407.43, V= 961.2（4） A3, Dc = 1.408 g/cm3, F（000） = 428, p = 0.210 mm^-1, the final R = 0.0484 and wR = 0.1195. In 1, the three-dimensional structure is organized into organic and inorganic regions; the flavone skeletons are stacked into organic regions by π...π staeking interactions; inorganic regions are generated by Na-O coordination bonds among sulfonate groups, coordinated water molecules and NaI. The sulfonate groups play an important role as a bridge of inorganic and organic regions. One-dimensional chain structure of 2 is extended by N-H…O hydrogen bonds and π...π stacking interactions. Furthermore, the antioxidant activity of 1 was evaluated. The scavenging activity of 1 to DPPH free radical is better than that of the parent compound chrysin.

Phenolic Contents and Antioxidant Activity of Various Date Palm (<i>Phoenix dactylifera </i>L.) Fruits from Saudi Arabia

The present study aimed to estimate the individual and total phenols and antioxidant activity of the aqueous and alcoholic extracts of three premium quality date varieties (Khalas, Sukkari and Ajwa) from Saudi Arabia. In general, water extract has shown significantly higher contents of total phenols than alcoholic, especially in Ajwa (455.88 and 245.66 mg/100 g respectively). However, phenolic profile indicated that Sukkari contained the highest rutin concentration (8.10 mg/kg), whereas, catechin was approximately the same in Sukkari and Ajwa (7.50 and 7.30 mg/kg respectively). Khalas was the highest variety content of caffeic acid (7.40 mg/kg). A significant difference has indicated among extracts and varieties in suppressing lipid peroxidation. Sukkari and Ajwa have reduced the oxidation with 50% at lower concentration in water extract than alcoholic (0.63, 0.70 and 1.60, 1.43 mg/ml respectively). Furthermore, high positive linear correlation was found between total phenols in water (r = 0.96) and alcohol (r = 0.85) extracts and inhibition of lipid oxidation activity. The compounds responsible for the activity were catechin (r = 0.96), and rutin (r = 0.74) in water extract, whereas this correlation decreased in alcoholic extract (r = 0.66) for catechin and very weak (r = 0.38) for rutin. No correlation was found between caffeic acid and lipid peroxidation in both extracts. Similar significant results were obtained with DPPH test, except with Sukari, which has shown no difference between aqueous and alcoholic extracts (4.30, 4.10 mg/ml respectively).

Antioxidant Activity of Hydro-Acetonic, Hydro-Methanolic and Aqueous Leaf and Bark Extracts of <i>Sclerocaria birrea</i>(A. Rich.) Hochst

Bioactive compounds in plants are associated with the reduction of chronic diseases. The free radical scavenging activity of different extracts of a medicinal plant, Sclerocarya birrea, has been investigated using the DPPH test, ABTS test and FRAP. Three extracts were prepared from the leaves and bark: hydro-methanolic, hydro-acetonic and aqueous. Phytochemical screening was carried out the standard methods followed by the determination of the polyphenol by Folin-Ciocalteu method. The analysis of variance (ANOVA) with the STATISTICA 7.1 and statistical significance was set at p < 0.05. Evolution of percent inhibition (PI) as well as the IC50 of the extracts was obtained using the Origin Pro 8.5 software and Microsoft Excel. The results show that the bark extracts are about twice as rich in polyphenols as the leaves. With DPPH at 1.25 mg/mL, the bark has a PI of 91.04% ± 0.001% while leaves, reach 99.80% ± 0.021%. As for the ABTS test, the bark extract reached its maximum activity at 1.25 mg/mL with a PI of 99.80% ± 0.003% while leaves extract greater value of PI is 99.75 ± 0.003 at 2.5 mg/mL. With FRAP test at 1.25 mg/mL, the bark has a PI of 79.29% ± 0.005% while leaves, reach 80.33% ± 0.001%. The IC50 of the bark and leaf extracts on the smallest DPPH are 0.156 ± 0.001 mg/mL in hydro-methanol, 0.301 ± 0.00 mg/mL in hydro-acetone and 0.407 ± 0.00 mg/mL in aqueous extract. With ABTS test, the best IC50 are obtained with hydro-acetone extracts with value of 0.247 ± 0.001 mg/mL for bark and 0.248 ± 0.0005 mg/mL for leaves while in hydro-methanolic and aqueous extracts the best IC50 are respectively 0.255 ± 0.00 mg/mL and 0.463 ± 0.00 mg/mL. Using ascorbic acid as our standard, the PI was 94.86% ± 0.008% with an IC50 of 0.213 ± 0.00 mg/mL. According to these results, the reducing power of the bark is slightly higher than that of the leaves. We can say that the bark has better activity than the leaves and the alcoholic extracts have given better results than the aqueous extract.

Study on Antioxidant Activity of Different Extracts of Gynura segetum in vitro

[Objectives]To study the antioxidant activity of different solvent extracts of Gynura segetum in vitro,so as to provide experimental basis for further study and utilization of medicinal resources of G.segetum.[Methods]The antioxidant activity of different solvent extracts of G.segetum was determined by UV-vis spectrophotometer using DPPH free radical scavenging method and ABTS^+free radical scavenging method.[Results]The scavenging rates of DPPH and ABTS^+by acetone extract were high,reaching 98.9%and 98.3%,respectively;the scavenging rate of DPPH and ABTS^+by water extract was the lowest,and the scavenging rates were 76.7%and 77.5%,respectively.The order of ABTS^+radical scavenging rate of samples extracted with different extractants was as follows:S 5(acetone extract)>S 1(ethyl acetate extract)>S 6(ethanol extract)>S 4(n-butanol extract)>S 3(methanol extract)>S 2(distilled water extract);the order of DPPH radical scavenging rate of samples extracted with different extractants was as follows:S 5(acetone extract)>S 1(ethyl acetate extract)>S 4(n-butanol extract)>S 6(ethanol extract)>S 3(methanol extract)>S 2(distilled water extract).[Conclusions]The extracts of acetone,ethyl acetate,n-butanol,anhydrous ethanol,methanol and distilled water from the roots of G.segetum had obvious scavenging effects on DPPH and ABTS^+,all had antioxidant components,and acetone had the highest antioxidant effect as an extractant.