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%.

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.

Chemical composition and free radicals restraining activity of extracts from three Manglietia species leaves

The extracts from leaves of Manglietia insignis （Wall） Blume, Manglietia chingii Dandy and Manglietia yuyuanensis Law were prepared by organic solvent extraction and their components were analyzed by GC/MS and quantified. Meanwhile, the free radicals restraining activities were detected. The 21 compounds in M. insignis, 36 compounds in M. chigii and 20 compounds in M. yuyuanensis were identified. There were 11 common components in the extracts from three Manglietia species, and 12 components in two Manglietia species. The results of relative contents of every component in three extracts showed that the main constituents of M. insignis were terpenoids and alkene, amounting to 38.93%, followed by alkane （28.18%）, the nitrogen containing compounds （15.73%） and aromatic compounds （7.23 %）. The main constituents of leaf extract from M. chingii were the terpenoids and alkene, carboxylic acid, alkane and aromatic compounds, amounting to 30.22%, 14.17%, 13.87% and 13.29%, respectively, The main constituents of M. yuyuanensis were alcohol compounds, the terpenoids and alkene, and aromatic compounds, amounting to 28.00%, 25.38% and 18.00% respectively. The results showed that the three extracts had strong function of restraining oxygen free radicals. The ultra oxygen anions activity was restrained at the highest level, when the three extracts were diluted by hundred-fold, whereas the restraining capacity of hydroxyl free radicals reached maximum, when the three extracts were diluted by twenty-fold. The above results provide scientific evidences for further approaching the ecological healthy function of three MangUetia species

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.

Synthesis of thiadiazole-based Schiff base metal complexes and their inhibition rate to superoxide anion free radical

A new series of Schiff base ligands were synthesized by the condensation of 2-amino-5-mercaptan-l,3,4-thiadiazole and salicylaldehyde or 2,4-dihydroxybenzaldehyde and their derivatives with choroacetic acid, and further reaction with corresponding metal acetate to form metal complexes. The compositions and structures of the ligands and their complexes were characterized by elemental analysis, molar conductivities, electronic absorption spectra and infra-red spectra. Their inhibition rates to free radical, such as O2, were also tested. The results show that all of the obtained complexes display significant activities, among which the copper（Ⅱ） complexes have the best inhibitive effects.

The Maturation and Senescence in Relation to Ca^2+,CaMContent and Ca^2+-ATPase Activity and Active OxygenMetabolism in Strawberry Fruits

The changes in content of Ca2 + and CaM, Ca2 + -ATPase activity and active oxygen metabolism during strawberry (Fragaria ananassa Duch. cv. Chunxing) fruits maturation and senescence were investigated in this study. The results showed that the soluble Ca2+ content and SOD activity in fruits tended to decline and O2 production rate to increase, the Ca2 + -ATPase activity peaked at first and then declined during fruits maturation and senescence. There were the highest CaM content at white stage in preharvest fruits and at marked senescence stage in postharvest ones. The above biochemical changes in fruits stored at low temperature (4℃)were slower than those stored at normal temperature(25℃). Thus, it indicated that the stimulation of calcium messenger system and accumulation of active oxygen free radical were closely related to fruits maturation and senescence.

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.

Cadmium Accumulation and Its Toxicity in Brittle Culm 1(bc1),a Fragile Rice Mutant

Cadmium （Cd） accumulation and toxicity in rice plants were characterized and identified by using brittle culm 1 （bcl）, a fragile rice mutant and its wild type （Shuangkezao, an indica rice） as materials by hydroponics. The low Cd level didn＇t obviously affect the growth parameters in both rice genotypes, but under high Cd levels （1.0 and 5.0 μmol/L）, the growth of both rice plants were substantially inhibited. Moreover, bcl tended to suffer more seriously from Cd toxicity than Shuangkezao. Cd accumulation in both rice plants increased with the increase of Cd levels. There was a significant difference in Cd accumulation between the two rice genotypes with constantly higher Cd concentration in bcl, which also accumulated more Cd at 0, 0.1, and 1.0 μmol/L Cd levels. The same case was found in the two rice plants grown on Cd-contaminated soil. This suggested that cell wall might play an important role in Cd accumulation in rice plants by the physiological mechanisms. The malondialdehyde （MDA） content, superoxide dismutase （SOD） and peroxidase （POD） activities in rice plants were affected differently under Cd treatments, and which implied that POD might play the main role in detoxifying active oxygen free radical. A significant difference in antioxidative system between the two rice genotypes was found with constantly higher MDA content, SOD and POD activities in bcl. In summary, bcl accumulated more Cd and appeared to be more sensitive to Cd stress compared with its wild type.

Effect of pH on Antioxidant and Phytochemical Activities of Mulhatti Roots (Glycyrrhiza glabra L.)

Glycyrrhiza glabra L.is the most widely used herb in the ancient history of Ayurvedic medicine,as a medicinal value as well as an aromatic herb,and it is commonly known as Mulhatti.Mulhatti roots are useful for medically and are also a good source of phytoproducts and secondary metabolites present in Mulhatti roots are triterpenoid saponin,glycosides,glycyrrhizin,prenylated biaurone,licoaagrone,7-acetoxy-2-methylisoflavone,4-methylcoumarin,liqcoumarin,glycyrrhetinic acid,quercetin,liquiritigenin,isoliquiritigenin,etc.This study was carried out to study the evaluation of phenolic compounds,2,2-diphenyl-1-picrylhydrazyl(DPPH)free radical activity and general antioxidant capacity of water extracts of Mulhatti roots prepared at different pH values,namely 2,4,7 and 9.Data have shown great differences in terms of results.Most of the phenolic compounds are at pH 7(19.25),followed by pH 9(17.25),pH 2(14.62)and pH 4(8.89 mg GAE/g),respectively.Similarly,the flavonoid data also showed variations,the maximum has been present in pH 2(5.39),then pH 7(3.02),pH 9(1.79)and pH 4(1.40 mg CE/g),respectively.The value for DPPH IC50 free radical scavenging activity was the lowest at pH 7(82.22),followed by pH 2(110.40),pH 4(111.99)and pH 9(146.24μg/mL)and IC50 reference standard(ascorbic acid)was 59.52μg/mL in distilled water.The total capacity of the antioxidant was the highest at pH 2(9.93)followed by pH 4(5.54),pH 7(5.34)and pH 9(4.23 mg AAE/g).According to current research,pH 7 is the best for phytochemicals as well as antioxidants that catch harmful radicals.

Novel insights into the dehalogenation mechanism and ecotoxicity assessment of 6:2 Cl-PFESA from density functional theory calculations

The electroplating industry is the main source of 6:2 chlorinated polyfluorinated ether sulfonate(6:2 Cl-PFESA)pollution,which presents risks to human health and the environment.It is therefore crucial to develop effective 6:2 Cl-PFESA degradation techniques.Persulfate oxidation is a potential treatment method for 6:2 Cl-PFESA due to its outstanding oxidative degradability following the generation of the sulfate radical(SO_(4)^(•−))and hydroxyl radical(•OH).It has proven difficult to acquire a full understanding of the reaction mechanism and formation of intermediate(IM)products through conventional experimental studies because they are costly and time-consuming.Therefore,a theoretical analysis method based on density functional theory(DFT)calculations was applied.The DFT results showed that electron transfer for the degradation of 6:2 Cl-PFESA could be initiated by the protonated sulfate radical(HSO_(4)•,ΔG≠SET=9.16 kcal/mol),rather than SO4•−(ΔG≠SET=41.60 kcal/mol).After desulfonation,the reaction underwent stepwise decarboxylation cycles under the action of•OH,leading to the elimination of the CF_(2) units until there was complete mineralization into HCl,HF,and CO_(2).Furthermore,the IMs and the end products of 6:2 Cl-PFESA were evaluated using ECOSAR and TEST software.The low bioaccumulation of the short-chain IMs meant that they could be considered safe in terms of ecotoxicity and health effects.This research determined the theoretical and mechanistic basis of the effects of persulfate in the treatment of water containing 6:2 Cl-PFESA,and its structural analogues.

A new polyphenol, 1, 3-di-O-caffeoyl-5-O-(1-methoxyl-2-O-caffeoyl-4-maloyl)-quinic acid, isolated from cultured cells of Saussurea involucrata

The present study was designed to isolate the polyphenol constituents of cultured cells of Saussurea involucrata. The polyphenol type constituents were isolated using chromatography methods, and then characterized by spectral analysis. 1,1-Diphenyl-2-picrylhydrazyl radical 2,2-Diphenyl-1-(2,4,6-trinitrophenyl)-hydrazyl(DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid(ABTS) free radical scavenging were assayed using Vitamin C as the positive control. One new polyphenol 18, 1, 3-di-O-caffeoyl-5-O-(1-methoxyl-2-O-caffeoyl-4-maloyl)-quinic acid, together with 17 known compounds, was isolated and characterized. In conclusion, Compound 18 was a new caffeoyl maloyl quinic acid type polyphenol and showed desired vitro anti-oxidant activity. Compounds 1–5, 9, 10, 14, 15, and 17 were isolated from cultured cells of Saussurea involucrata for the first time.

The Potential Effect of Puerarin in Preventing Atherosclerosis

Objective To study the activity of Puerarin (Pue) in scavenging oxygen free radical (OFR) and its inhibitory effect on the oxidative modification of low density lipoprotein (LDL). Methods Riboflavin-light system was used to generate superoxide anion, and Fenton reaction to generate hydroxyl free radical to study the activity of Pue in scavenging OFR. Hydrogen peroxide-induced hemolysis was used to study the effect of Pue on erythrocyte hemolysis and malondialdehyde (MDA) production. And ultraviolet ray and cupric sulfate were used to cause the oxidative modification of LDL for studying the inhibitory effect of Pue on LDL oxidative modification. Results (1) Pue could, at concentration of 0. 01 – 1.0 mmol/L, scavenge superoxide anion radical and at concentration of 7.5–75μmol/L scavenge hydroxyl radical in a concentration dependent manner. (2) Pue could, at concentration of 0.1–10 mmol/L, inhibit significantly oxidative hemolysis and MDA production of erythrocyte induced by hydrogen peroxide. (3) Pue of 0.01–1.0 mmol/L could inhibit the oxidative modification of LDL in a concentration dependent manner. Conclusion Pue has an anti-peroxidation effect and shows a potential effect in preventing atherosclerosis.

Evaluation of antioxidant activities of Hippophae rhamnoides Linn leaves extracts

Objective:To investigate the antioxidant activity of aqueous,methanol,ethanol,acetone,ethyl acetate,chloroform and n-hexane extracts of Hippophae rhamnoides(H.rhamnoides)leaves.Methods:Antioxidant activity was evaluated by using in-vitro antioxidant assays model 1,1’-diphenyl-2-picrylhydrazyl radical-scavenging activity.The antioxidant activities were compared with standard antioxidant agents such as ascorbic acid.Results:The antioxidant activities(%inhibition)of all the tested extracts were increased in the order i.e.menthol>ethanol>aqueous>acetone>chloroform>ethyl acetate>n-hexane.The methanol extract EC_(50)(μg/mL)value was compatible with vitamin C(standard).The antioxidant activity of H.rhamnoides leaves extracts increased in a dose dependent manner.Conclusions:It was observed that H.rhamnoides was a potential resource of antioxidants and thus could put off numerous radical linked diseases.

Preparation and Characterization of Two Wood Vinegars Obtained from Hull of Spina Date Seed and Shell of Peanut

Two new kinds of wood vinegars（WVs） from the hull of spina date seed（HSDS） and the shell of peanut（PS） were prepared. 32 Major components in the two kinds of WVs were identified and determined by gas chro- matograph-mass spectrometery. The total phenolic content was determined and the antioxidant activity of the WV was measured. The total phenolic contents of PSWV and HSDSWV were 75.9 and 98.1 rag/L, respectively, when they were expressed as catechol equivalents. In 1,1-diphenyl-2-picrylhydrazyl assay, free radical scavenging activity of HSDSWV was also superior than that of PSWV. In addition, the antioxidant activities of the two kind of WVs exhibited a good positive correlation with total phenolic content, and the linear correlation coefficients ranged from 0.9594 to 0.9970. The two kind of WVs could be used in the fields of food and medicine due to their powerful antioxidant activities.

Reaction mechanism of dicofol removal by cellulase

It remains unclear whether dicofol should be defined as a persistent organic pollutant. Its environmental persistence has gained attention. This study focused on its degradation by cellulase. Cellulase was separated using a gel chromatogram, and its degradation activity towards dicofol involved its endoglucanase activity. By analyzing the kinetic parameters of cellulase reacting with mixed substrates, it was shown that cellulase reacted on dicofol and carboxyl methyl cellulose through two different active centers. Thus, the degradation of dicofol was shown to be an oxidative process by cellulase. Next, by comparing the impacts of tert-butyl alcohol（a typical OH free-radical inhibitor） on the removal efficiencies of dicofol under both cellulase and Fenton reagent systems, it was shown that the removal of dicofol was initiated by OH free radicals produced by cellulase. Finally, 4,4′-dichlorodibenzophenone and chloride were detected using gas chromatography mass spectrometry and ion chromatography analysis, which supported our hypothesis. The reaction mechanism was analyzed and involved an attack by OH free radicals at the orthocarbon of dicofol, resulting in the degradation product 4,4′-dichloro-dibenzophenone.