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.

Component Analysis and Free Radicals Scavenging Activity of Physalis alkekengi L. Polysaccharide

A crude polysaccharide was extracted from Physalis alkekengi L. fruit. HPLC was used for the component analysis of the polysaccharide. The results indicate that Physalis alkekengi L. polysaccharide（PAP） was composed of rhamnose, xylose, arabinose, galactose, and glucose. Free radicals scavenging activity of PAP was studied through 3 free radicals scavenging tests. PAP exhibited high scavenging effects on OH and DPPH radicals, and both the scavenging rates were about 80%. The scavenging rate of O2^- radical was about 22%.

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.

Flavonoid content and radical scavenging activity in fruits of Chinese dwarf cherry(Cerasus humilis) genotypes

The Chinese dwarf cherry（Cerasus humilis（Bge.） Sok.） is a small shrub with edible fruits. It is native to northern and western China. This species was included as a medicinal plant in the ‘‘Chinese Pharmacopeia’’ and has emerged as an economically important crop for fresh fruit consumption, processing into juice and wine and nutraceutical products as well. To gain a better understanding of flavonoid biosynthesis and help develop value added products and better cultivars with greater health benefits, we analyzed total flavonoid content（TFC）, composition, and radical scavenging activities in fruit extracts of 16 Chinese dwarf cherry genotypes. Fruit peel TFC ranged from 33.5 to72.8 mg/g REáFW（RE： rutin equivalent, FW： fresh weight）while fruit flesh TFC ranged from 4.3 to 16.9 mg/g REáFW.An HPLC analysis revealed that fruit extracts contained 14 flavonoids with considerable variation in their profiles across genotypes. The most abundant flavonoids in most genotypes were proanthocyanidin B1（PA-B1）, proanthocyanidin B2（PA-B2）, phloretin 20-O-glucoside（PG）, and phloretin 20,40-O-diglucoside（PDG）. Principal component analysis showed that PG, PA-B1, and PA-B2 had large,positive factor loading values in the first principal component for each genotype. Increased scavenging activity of2,2-diphenyl-1-picrylhydrazyl（DPPH） radicals was apparent in genotypes ‘Nongda 4’, ‘Nongda 3’, ‘Nongda 6’,‘Wenfenli’, and ’10-32’, suggesting promising applications in the production of nutraceutical products. In summary, our results will aid in breeding, fruit processing, and developing medicinal uses of the Chinese dwarf cherry.

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.

Evaluation of free radical scavenging activity of various extracts of leaves from Kedrostis foetidissima(Jacq.)Cogn

The present study was aimed to investigate the in vitro free radical scavenging activity of various leaf extracts(aqueous,methanol,acetone chloroform and petroleum ether)of Kedrostis foetidissima.In vitro free radical scavenging activities of the extracts were assessed against DPPH and hydroxyl radicals.The metal chelating activity and reducing power ability of the extracts were also determined.The free radical scavenging activity was found to be high in methanolic extract for DPPH and hydroxyl radicals in a concentration dependent manner followed by chloroform,aqueous,acetone and petroleum ether extracts.The metal chelating activity and reducing power ability was also found to be high in methanolic extract.The difference in scavenging potential of the extracts may be due to variation in the percentage of phytoconstituents extracted in various solvents.Thus the result suggests that the methanolic leaf extract of K.foetidissima could serve as a potential source of antioxidants and can be explored as a therapeutic agent in free radical induced diseases.©2015 Beijing Academy of Food Sciences.Production and hosting by Elsevier B.V.All rights reserved.

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.

Study on the Free Radical Scavenging Activity of Sea Cucumber (Paracaudina chinens var.) Gelatin Hydrolysate

Gelatin from the sea cucumber(Paracaudina chinens var.) was hydrolyzed by bromelain and the hydrolysate was found to have a high free radical scavenging activity. The hydrolysate was fractionated through an ultrafiltration membrane with 5 kDa molecular weight cutoff(MWCO). The portion(less than 5 kDa) was further separated by Sephadex G-25. The active peak was col-lected and assayed for free radical scavenging activity. The scavenging rates for superoxide anion radicals(O2·-) and hydroxyl radi-cals(·OH) of the fraction with the highest activity were 29.02% and 75.41%,respectively. A rabbit liver mitochondrial free radical damage model was adopted to study the free radical scavenging activity of the fraction. The results showed that the sea cucumber gelatin hydrolysate can prevent the damage of rabbit liver and mitochondria.

Sonme Factors that Affect the Free Radical-scavenging Activity of Tea Extracts

Some factors that affect the free radical-scavenging activety of two tea extracts were studied in vitro. It was found that concentration of tea extract or heating tea extract or treating with activated carbon and diatomite all had obvious effect on the scavenging activety of green tea extract ,but heating or treating with diaomite had less effect on the scavenging activity of black tea extract. Ascorbic acid, for having synergic effect with tea extracts, could enhance the scavenging activity of tea extracts markedly, and the contrary was cupric ion. Reducing sugars such as fructose and glucose also had some syncrgic effect to tea extracts.

Factors Influencing the Effects of Theabrownin in Pu-erh Tea on Scavenging DPPH Radicals

[Objective] This study aimed to explore factors influencing the effects of theabrownin in Pu-erh tea on scavenging DPPH radicals. [Method] Taking Pu-erh tea as main research object, theabrownin in Pu-erh tea from tea piles with different times of mixture, stored for different years and processed by both the old and new techniques were extracted and isolated. And DPPH method was used to study the effects of theabrownin solution and tea liquor on scavenging radicals and their antioxidant activity. [Result] The result showed that the theabrownin content in Pu-erh tea from tea piles with one to four times of mixture revealed a first declining and subsequently rising trend. Under different pH conditions, the rates of DPPH radical scavenging of 1 mg/ml theabrownin solution made from tea piles with different times of mixture decreased gradually with the increase of pH, and all the rates were lower than that of the control vitamin C solution; the rates of DPPH radical scavenging of theabrownin from tea samples stored for different years and produced by different techniques dropped slowly within pH range 3.0-6.0; when pH was higher than 6.0, the rates of DPPH radical scavenging of theabrownin from tea samples produced by both new and traditional techniques in 2001 declined obviously, while the declining trend was not obvious in either the black tea or the Pu-erh tea produced by new technique in 2005. Under different theabrownin concentrations, the rates of DPPH radical scavenging of theabrownin solution made from tea piles with different times of mixture ascended as the concentration increased and the highest rate occurred in tea pile with four times of mixture, reaching up to 46.56%±0.88%; for tea samples stored for different years and produced by different techniques, the rates of DPPH radical scavenging of theabrownin rose gradually with the increase of the theabrownin concentration; the rate of radical scavenging of theabrownin in the black tea ascended obviously and that in Pu-erh tea was decreasing within the concentration range of 0.04 -0.06 mg/ml. At pH6.0, the DPPH radical scavenging ability of theabrownin in 0.1 mg/ml theabrownin solution and tea liquor containing 0.1mg/ml theabrownin from tea piles with different times of mixture ascended with the time of mixture; solution made from tea samples produced by different techniques in different years, the DPPH radical scavenging ability of theabrownin solution and tea liquor followed： Pu-erh tea produced by the new technique in 2001 ﹥ Pu-erh tea produced by the old technique in 2001﹥ Pu-erh tea produced by the new technique in 2005. And the DPPH radical scavenging ability of theabrownin in tea liquor containing 0.1 mg/ml theabrownin was higher than that in 0.1 mg/ml theabrownin Solution made from tea samples either with different times of mixture or produced by different techniques in different years. The above results indicated that many factor influenced the effects of theabrownin on eliminating DPPH radicals, including the time of fermentation, fermentation technique, years of storage, concentration and pH all had great influence on the effects of theabrownin on eliminating radicals. To ensure a good effect on scavenging radicals, it is better to prepare theabrownin at pH6.0 with concentration between 0.08 and 0.1 mg/ml for drinking. [Conclusion] Results of this study provide a basis for developing functional products of theabrownin from Pu-erh tea in the future.

Free Radical-Scavenging Properties and Antioxidant Activity of Fractions from Cranberry Products

Lipid peroxidation inhibition capacity and antiradical activity were evaluated in HPLC fractions of different polarity obtained from two cranberry juices and three extracts isolated from frozen cranberries and pomace containing antho-cyanins, water-soluble and apolar phenolic compounds, respectively. Compounds with close polarities were collected to obtain between three and four fractions from each juice or extract. The cranberry phenols are good free radi-cal-scavengers, but they were less efficient at inhibiting the lipid peroxidation. Of all the samples tested, the intermediate polarity fraction of extract rich in apolar phenolic compounds of fruit presented the highest antiradical activity while the most hydrophobic fractions of the anthocyanin-rich extract from fruit and pomace appeared to be the most efficient at inhibiting the lipid peroxidation. The antioxidant or pro-oxidant activity of fractions increased with the con-centration. The phenol polarity and the technological process to manufacture cranberry juice can influence the antioxidant and antiradical activities of fractions.

Radical Scavenging Ability of Soymilk Fermented with Compound Lactic Acid Bacteria towards DPPH Free Radical

The DPPH scavenging ability of soymilk fermented with lactic acid bacteria under different fermentation conditions were investigated in this paper. According to the result, the optimal combination of starter species was S. thermophilus, L. plantarum and L. helveticus at a ratio of 2∶1.5∶1.5. The optimal fermentation parameters were temperature of 37 ℃, solids content of 12% and fermentation time of 6 h.Under above conditions, the fermented soymilk showed the highest ability to scavenge DPPH free radicals（84.3%）. Besides, the radical scavenging ability of fermented soymilk was compared with that of Baiyu lactone soymilk and bean curd which were coagulated by chemical method. The result indicated that the scavenging rate of lactone bean curd of Baiyu lactone soymilk and bean curd was only32.1% and 23.2%. According to the comparison, the free radical scavenging ability of soymilk was significantly improved by lactic acid fermentation. This product which had no beany flavor would be beneficial to human health.

Peroxynitrite Scavenging Activities of Resveratrol and Piceid

In vitro antioxidant activities of resveratrol and piceid against peroxynitrite（ONOO-） were examined by the inhibition of 3-nitrotyrosine formation.Trolox was used as a positive control.Resveratrol and piceid exhibited high ONOO--scavenging activities in a concentration dependent manner.The antioxidant activities（the concentration of test compound required to yield a 50% inhibition of tyrosine nitration,IC 50） of resveratrol and piceid against ONOO-were（48.34±0.97） and（74.69±1.49） μmol/L,respectively.Compared with that of trolox[（105.40±1.16） μmol/L],their scavenging activities were 2.2-and 1.5-fold higher for resveratrol and piceid.Formation of nitroresveratrol as shown by UV-Vis spectroscopy and liquid chromatography-tandom mass spectrometry（LC-MS/MS） analysis indicates that resveratrol could directly scavenge ONOO-via nitration reaction.Our results demonstrate that foods and medicinal herbs with resveratrol and piceid as stronger ONOO-scavengers are valuable ingredients and have healthy application in preventing humans from peroxynitrite-mediated oxidative damage by scavenging peroxynitrite efficiently.

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.

DPPH Radical Scavenging Capacity of Phenolic Extracts from African Yam Bean (<i>Sphenostylis stenocarpa</i>)

The phenolic extracts of the seeds of African yam bean (Sphenostylis stenocarpa) were studied using different extraction solvents (70% ethanol, 80% acetone and acidic 70% acetone) and two heat treatment methods (dry heating on a hot plate with acid-washed sea sand at 135℃ for 25 min and wet heating in an autoclave at 120℃ for 20 min). The study examined the total phenolic content (TPC), total flavonoid content (TFC), and condensed tannin content (CTC) of the seed extracts, as well as their free radical scavenging and antioxidant properties. The raw African yam bean seed was dry heated in air oven at 100℃ for 5 min (control). Heat treatments application affected the phenolic contents of the seeds significantly (p < 0.05). The free radical scavenging activity of the phenolics were done using 2,2-diphenyl- 1-picrylhydrazyl (DPPH). The effectiveness of the extract was determined using DPPH at 50 mg/g, 10 mg/g and 5 mg/g of the extracts. At 5 mg/g, the extract was most effective indicating that higher concentration of extract gave higher antioxidant activity. The seed has high antioxidant capacity and an appreciable amount of phenolic extracts.

Physicochemical and radical scavenging activities of honey samples from Malaysia

The physical properties, total phenols, total flavonoid content and free radical scavenging activities of honey samples from Malaysia were investigated. The physical properties of Tualang, Gelam and Acacia honey samples, in terms of pH, color, moisture, electrical conductivity and total soluble solid were significantly different (p = 0.000). Gelam honey was reported to have the highest total phenols (606.17 mg GAE/kg honey) and flavonoid content (183.43 mg RE/kg honey). Tualang honey was reported to have the highest free radical scavenging activity with the IC50, 72.75 g/L compared to Gelam (77.41 g/L) and Acacia (90.83 g/L). There is no significant difference has been revealed among honey samples for radical scavenging activity (p = 0.827). Nevertheless, strong correlation was obtained between pH, color, electrical conductivity and total soluble solid with the scavenging activity of all honey samples with the correlative coefficient, r = 0.979, 0.902, 0.917 and 0.957, respectively. The establishment of the statistical correlation could be useful for honey related industry.

Effect of Cd, Pb Stress on the Activated Oxygen Scavenging System in Tobacco Leaves

The effect of Cd, Pb stress on the activated oxygen scavenging system indicates thatthe content of chlorophyll, chlorophyll a/b ratio and the activity of CAT gradually decrease,the activity of SOD increases first and then decreases, and the activity of POD gradually increases with increasing concentrations of Cd and Ph. Between Cd and Ph there is synergism inthe activated oxygen scavenging system. The results show that the stress of Cd and Pb can affect the scavenging system of activated oxygen and result in imbalance of activated oxygenmetabolism.

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.