AIM:To investigate the effects of the free radical scavenger bis(1-hydroxy-2,2,6,6-tetramethyl-4-piperidinyl) decandioate(IAC) in the dextran sodium sulphate(DSS) experimental model of ulcerative colitis.METHODS:Colit...AIM:To investigate the effects of the free radical scavenger bis(1-hydroxy-2,2,6,6-tetramethyl-4-piperidinyl) decandioate(IAC) in the dextran sodium sulphate(DSS) experimental model of ulcerative colitis.METHODS:Colitis was induced in Sprague Dawley male rats by administration of 5% DSS in drinking water.IAC(30 mg/kg,lipophilic or hydrophilic form) was administered daily(orally or ip) for 6 d until sacrifice.Colonic damage was assessed by means of indirect(Disease Activity Index score) and direct measures(macroscopic and microscopic scores) and myeloperoxidase(MPO)activity.Neutrophil infiltration within the tissue and glutathione S-transferase activity were also investigated.RESULTS:DSS-induced colitis impaired body weight gain and markedly increased all inflammatory parameters.Six-day treatment with lipophilic IAC significantly reduced intestinal damage caused by inflammation,induced a down-regulation in MPO activity(0.72 ± 0.12 and 0.45 ± 0.12 with lipophilic IAC po and ip,respectively,vs 1.10 ± 0.27 in untreated DSS colitis animals) and minimized DSS-induced neutrophil infiltration,while hydrophilic IAC administered orally did not ameliorate DSS-induced damage.CONCLUSION:These results support the hypothesis that reactive oxygen metabolites contribute to inflammation and that the radical scavenger IAC has therapeutic potential in inflammatory bowel disease.展开更多
Photoelectrocatalytic degradation performance of quinoline in saline water was investigated using a new-designed continuous flow three-dimensional electrode-packed bed photocatalytic reactor. It is interesting to find...Photoelectrocatalytic degradation performance of quinoline in saline water was investigated using a new-designed continuous flow three-dimensional electrode-packed bed photocatalytic reactor. It is interesting to find that chloride ion has an obvious enhancement effect rather than a scavenging effect on the photoelectrocatalytic degradation of quinoline, and create a kinetic synergetic effect in the photoelectrocatalytic reactor.展开更多
[Objectives]To study the optimum conditions of solid fermentation of natto with antioxidant function as an index.[Methods]Single factor experiment and orthogonal experiment were designed to study the effects of temper...[Objectives]To study the optimum conditions of solid fermentation of natto with antioxidant function as an index.[Methods]Single factor experiment and orthogonal experiment were designed to study the effects of temperature,time,initial pH and inoculum amount on the antioxidant activity of natto solid fermentation.The optimum conditions of natto solid fermentation were determined and the antioxidant ac-tivity of natto extract was compared.[Results]The optimal fermentation conditions were as follows:temperature 32℃,initial pH 7.0,inocu-lation amount 8%,fermentation time 32 h.The hydroxyl radical scavenging rate of natto solid fermentation crude extract was the highest,which was 82.7%.The optimized nato fermentation extract showed stronger scavenging ability for-OH and O,:,and showed obvious dose-effect relationship.ICso was 3.63 and 4.24 mg/mL,respectively,and the scavenging efficiency was 1.3 and 1.9 times higher than that of the unoptimized fermentation extract,respectively.[Conclusions]Natto is rich in nattokinase and other functional factors,and its antioxidant ac-tivity can be improved by optimizing fermentation technology,so that natto products can be widely used,including cosmetic raw materials,nat-to skin care soap,health food and medicine,etc.,and have a broader development prospect.展开更多
Four naturally rare 5,6,7-trimethoxy-2,3-cis-dihydroflavonols (3-6) and two 5,6,7-trimethoxy-2,3-trans-dihydroflavonols (7-8) were designed and synthesized. Their antioxidative properties were evaluated by way of ...Four naturally rare 5,6,7-trimethoxy-2,3-cis-dihydroflavonols (3-6) and two 5,6,7-trimethoxy-2,3-trans-dihydroflavonols (7-8) were designed and synthesized. Their antioxidative properties were evaluated by way of examining their scavenging capacities towards DPPH and O2^*- free radicals, as well as by measuring their inhibitory ability against LPO. Both the 2,3-trans and the 2,3- cis conformers exhibited certain quenching abilities to DPPH and O2^*- radicals, while most of the synthetic dihydroflavonols demonstrated remarkable inhibition to LPO.展开更多
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...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%.展开更多
The flower of Butea monosperma(Lam.)(Fabaceae)has been used in traditional Indian medicine in the treatment of many ailments including liver disorders.To understand the pharmacological basis of its beneficial effects,...The flower of Butea monosperma(Lam.)(Fabaceae)has been used in traditional Indian medicine in the treatment of many ailments including liver disorders.To understand the pharmacological basis of its beneficial effects,the extracts of dried flowers in water,methanol,butanol,ethyl acetate and acetone were evaluated for free radical scavenging and pro-apoptotic activities in cell cultures(human hepatoma Huh-7 cell line and immortalized AML-12 mouse hepatocytes).Butrin and butein-the active constituents of flower extracts-were used as reference molecules.The levels of cell injury markers like lactate dehydrogenase,glutathione and lipid peroxidation and primary antioxidant enzymes glutathione S-transferase and catalase were also measured.The aqueous and butanolic extracts exhibited better 2,2-diphenyl-1-picrylhydrazyl scavenging and cytotoxic activities in hepatoma cells than in immortalized hepatocytes.Interestingly,butein inhibited 2,2-diphenyl-1-picrylhydrazyl radical better than butrin.The aqueous and butanolic extracts were further investigated for hepatoprotection against carbon tertrachloride-induced biochemical changes and cell death.Both extracts,just as butrin and butein,significantly reversed the cellular glutathione levels and lipid peroxidation,and glutathione–S-transferase activity.Lactate dehydrogenase leakage and cell death were also prevented.However,only butein revived the catalase activity.Thus,the butein content of Butea monosperma flower extracts is important for free radical scavenging activity,apoptotic cell death and protection against oxidative injury in hepatic cells.展开更多
BACKGROUND: The fluidity of cell membrane can be affected by various factors. Many experiments have confirmed that the ischemia/reperfusion of organic tissue can increase the contents of free radicals, which lead to h...BACKGROUND: The fluidity of cell membrane can be affected by various factors. Many experiments have confirmed that the ischemia/reperfusion of organic tissue can increase the contents of free radicals, which lead to high rigidity and low fluidity of cell membrane, and the conditions can be changed by Chuanxiongqin. OBJECTIVE: To observe the effect and mechanism of Chuanxiongqin hydrochloride on the fluidity of brain cell membrane in rat models of ischemia/reperfusion. DESIGN: A completely randomized controlled animal trial. SETTINGS: Institute of Brain Sciences; Department of Physiology, Medical College, Datong University. MATERIALS: Twenty male grade Ⅰ Wistar rats of 170-220 g were randomly divided into model group (n =10) and control group (n =10). Chuanxiongqin hydrochloride (molecular mass was 172.2) was purchased from the National Institute for the Control of Pharmaceutical and Biological Products (batch number: 0817-9803); Spin labelers: 5-doxyl-stearlic acid methylester (5DS), 16-doxyl-stearlic acid methylester (16DS), xanthine, xanthine oxidase (XOD) and 5,5-dimeth-1-pyrroline- N-oxide (DMPO) from Sigma Company; Bruker ESP 300 electron paramagnetic resonance (EPR) spectrometer by Bruker Company (Germany). METHODS: The experiments were carried out in the State Key Laboratory of Natural and Biomimetic Drugs, Peking University from June 2001 to July 2002. In the model group, rats were made into models of cerebral ischemia by 30-minute ligation and 2-hour reperfusion of common carotid arteries; The rats in the control group were not made into models. The order parameter (S) and rotational correlation time (τc) were detected with the ESR spectrometer by means of spin labeling. The greater the S and τc, the smaller the fluidity. Meanwhile, the clearance rate of free radicals was detected with ESR spin trapping. The measurement data were compared using the t test. MAIN OUTCOME MEASURES: The S, τc and clearance rates of O2 · and OH· free radicals were compared between the model group and control group. RESULTS: The S and τc in the model group [0.738 4±0.003 5; (8.472±0.027)×10-10 s/circle] were obviously different from those in the control group [0.683 9±0.008 3; (7.945±0.082)×10-10 s/circle, t =5.731, 5.918, P < 0.05], which suggested that ischemia/reperfusion injury decreased the fluidity of brain cell membrane. After adding Chuanxiongqin hydrochloride, there were no obvious differences between the model group [0.688 5±0.030 5; (7.886±0.341)×10-10 s/circle] and control group (P > 0.05), indicating that Chuanxiongqin hydrochloride could recover the fluidity of brain cell membrane after ischemia/reperfusion injury close to the level in the normal control group. Chuanxiongqin hydrochloride could directly scavenge the O2 · and OH· free radicals, and the maximal clearance rates were 83.92% and 44.99% respectively. CONCLUSION: Chuanxiongqin hydrochloride increases the fluidity of membrane of ischemia-injured brain cell by scavenging both O2 ·and OH· free radicals.展开更多
The static O-H bond parameters including O-H bond length, O-H charge difference, O-H Mulliken population and O-H bond stretching force constant (k) for 17 phenols were calculated by ab initio method HF/6-31G**. In com...The static O-H bond parameters including O-H bond length, O-H charge difference, O-H Mulliken population and O-H bond stretching force constant (k) for 17 phenols were calculated by ab initio method HF/6-31G**. In combination with the O-H bond dissociation enthalpies (BDE) of the phenols determined by experiment, it was found that there were poor correlationships between the static O-H bond parameters and O-H BDE. Considering the good correlationship bt tween O-H BDE and logarithm of free radical scavenging rate constant for phenolic antioxidant, it is reasonable to believe that the ineffectiveness of static O-H bond parameters in characterizing antioxidant activity arises from the fact that they cannot measure the O-H BDE.展开更多
The synthesis of (±)-5, 6, 7-trioxygenated dihydroflavonols was carried out. All synthetic compounds were passed through superoxide radical scavenging activity in vitro. Compounds 1 e and 1 g exhibited signific...The synthesis of (±)-5, 6, 7-trioxygenated dihydroflavonols was carried out. All synthetic compounds were passed through superoxide radical scavenging activity in vitro. Compounds 1 e and 1 g exhibited significant bioactivity with the inhibitory rates of 68.1% and 80.9% at 40 μg/mL, respectively.展开更多
This work aims to determine the phytochemical characterization of the pericarp of Chamaedorea radicalis Mart.fruit as a non-timber product with potential to obtain phytochemicals with potential applications in the ind...This work aims to determine the phytochemical characterization of the pericarp of Chamaedorea radicalis Mart.fruit as a non-timber product with potential to obtain phytochemicals with potential applications in the industry.Fruit from C.radicalis were grouped in four ripening stages named as S1,S2,S3 and S4,according to maturity;S1 the most unripe stage and S4 the completely ripe stage.Determinations of total phenolic compounds,free radical scavenging activities and total flavonoid contents using spectrophotometric methods were done.Also,the tentative identification of phytochemicals during fruit ripening was done using UPLC-MS-MS.Total phenolic compound(TPC)content ranged from 7.24 to 12.53 mg gallic acid equivalents per gram of fresh weight(mg GAE/g FW).Total flavonoids(TF)contents ranged from 0.163 to 0.23 mg of quercetin equivalents per g FW(mg QE/g FW).Free radical scavenging activity against DPPH and ABTS radicals varied from 40.80 to 53.68 and from 22.29 to 37.76 mmol Trolox equivalents g FW(mmol TE/g FW),respectively.Antioxidant assay in vitro by FRAP(ferric reducing antioxidant power)method showed that S3 was the highest level with antioxidant power while S4 was the lowest with Red ripeness stage showed the lowest contents for all determinations.Mass spectrometry allowed detection of 26 compounds,including phenolics,alkaloids and saponins.Afzelin,Kaempferol 3-neohesperidoside and the four saponins identified were present in all ripeness stages.Preliminary phytochemical identification and the spectrophotometric determinations showed that the pericarp of C.radicalis presented antioxidants and compounds related to alkaloids,phenolics and saponins.The presence and abundance of each phytochemical regarding each ripeness stage should be considered.展开更多
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 ...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.展开更多
[Objectives]To explore the extraction and in vitro antioxidant effects of astragalus polysaccharides(APS)and Ganoderma lucidum mycelia polysaccharides(GLMPS).[Methods]By studying the polysaccharides of the herbal medi...[Objectives]To explore the extraction and in vitro antioxidant effects of astragalus polysaccharides(APS)and Ganoderma lucidum mycelia polysaccharides(GLMPS).[Methods]By studying the polysaccharides of the herbal medicinal material Astragalus membranaceus and the fungal medicinal material Ganoderma lucidum mycelia,two polysaccharides were mixed according to different proportions and concentrations by using the principle of traditional Chinese medicine compound combination.The effect of polysaccharides on the scavenging ability of hydroxyl radical system was determined by salicylic acid method.[Results]When the compound ratios of GLMPS and APS were 1∶1,1∶4,1∶5,4∶1,and 5∶1,the scavenging effect of compound polysaccharides was better than that of single-component polysaccharides,and with the increase of concentration,the scavenging effect increased.When the ratio of GLMPS and APS was 5∶1,the hydroxyl radical scavenging rate of the compound polysaccharide reached 59.77%,which was 18.72%higher than that of single GLMPS and 28.58%higher than that of single APS.The scavenging effect of compound polysaccharide is closely related to the compound ratio and concentration.[Conclusions]APS and GLMPS can obtain better hydroxyl radical scavenging ability than single-component polysaccharides through compounding in appropriate proportions.In addition,within a suitable concentration range,as the concentration increases,the scavenging ability also increases.展开更多
Objective:To examine the effects of hydroalcoholic extract and fractions of Hordeum vulgare Linn.(H.vulgare,Da Mai)on streptozotocin(STZ)-induced diabetic nephropathy in Sprague-Dawley rat models.Methods:The study inv...Objective:To examine the effects of hydroalcoholic extract and fractions of Hordeum vulgare Linn.(H.vulgare,Da Mai)on streptozotocin(STZ)-induced diabetic nephropathy in Sprague-Dawley rat models.Methods:The study involved preliminary phytochemical screening of extract and fractions,estimation of secondary metabolites,chromatographic studies using high performance liquid chromatography(HPLC),antioxidant potential using 1,1-diphenyl-2-picrylhydrazyl(DPPH),nitric oxide radical scavenging and reducing power methods along with the determination of potential against diabetic nephropathy in STZ-induced rat models.Results:The phytochemical evaluation of the hydroalcoholic extract of H.vulgare and fractions revealed the presence of various phytoconstituents such as alkaloids,saponins,tannins,flavonoids,and glycosides.The chromatographic analysis indicated the peak complementing marker compound epicatechin and significant antioxidant activity in the extract and aqueous fraction.STZ-induced rats showed abnormal levels of serum albumin,creatinine,total cholesterol,blood urea nitrogen(BUN),and triglycerides,and urine albumin and creatinine,which returned to normal after 8 weeks of treatment with hydroalcoholic extract(400 mg/kg)and aqueous fraction(50 mg/kg)of H.vulgare.Conclusion:Hydroalcoholic extract(400 mg/kg)and aqueous fraction(50 mg/kg)of H.vulgare have significant antioxidant potential and positive effects on diabetic nephropathy.The fractionation and optimization increase the concentration of polyphenols in aqueous extract,causing a decrease in the dose required for effects against diabetic nephropathy.展开更多
Plant polyphenols are reported to have bioactive properties, which may be used for protection against diseases. Therefore, the aim of this research was to investigate the antioxidant activities of a pomegranate tannin...Plant polyphenols are reported to have bioactive properties, which may be used for protection against diseases. Therefore, the aim of this research was to investigate the antioxidant activities of a pomegranate tannin polyphenol compound, punicalagin and pomegranate juice. The presence of punicalagin in pomegranate husk (US) and pomegranate juice (US & UK) was compared with a punicalagin standard using high performance liquid chromatography (HPLC) and liquid chromatography-mass spectroscopy (LC-MS) which are highly sensitive and selective analytical methods for the separation and identification of phenolic compounds and anthocyanins. Antioxidant mechanisms involving DPPH radical scavenging activity, hydrogen peroxide scavenging, ferrous chelating and reducing ability were also studied on pomegranate juice and standard punicalagin. The present study shows a high degree of similarity of HPLC and LC-MS results between the punicalagin commercial standard (Sigma Aldrich) and US pomegranate husk extracted with methanol. In contrast, in the methanol juice extract obtained from US and UK, higher hydrogen peroxide scavenging activity was achieved by 0.1 mg/ml from both punicalagin and pomegranate juice when compared with butylated hydroxytoluene (BHT) or trolox (p ≤ 0.01). Punicalagin and pomegranate juice exhibited ferrous chelating ability significantly lower than Ethylenediaminetetraacetic acid. These findings confirmed that punicalagin was present in pomegranate husk compared to pomegranate juice, as measured using a punicalagin standard. The antioxidant mechanism experiments concluded that, the pomegranate juice has a significantly higher radical scavenging activity in comparison with punicalagin (p ≤ 0.01). However, punicalagin showed significant ferrous chelating activity and reducing power ability in a dose-dependent manner as compared with pomegranate juice.展开更多
The purpose of the experiment was to study the efficacy of edaravone in enhancing flap viability after ischemia/reperfusion(IR) and its mechanism. Forty-eight adult male SD rats were randomly divided into 3 groups:...The purpose of the experiment was to study the efficacy of edaravone in enhancing flap viability after ischemia/reperfusion(IR) and its mechanism. Forty-eight adult male SD rats were randomly divided into 3 groups: control group(n=16), IR group(n=16), and edaravone-treated IR group(n=16). An island flap at left lower abdomen(6.0 cm×3.0 cm in size), fed by the superficial epigastric artery and vein, was created in each rat of all the three groups. The arterial blood flow of flaps in IR group and edaravone-treated IR group was blocked for 10 h, and then the blood perfusion was restored. From 15 min before reperfusion, rats in the edaravone-treated IR group were intraperitoneally injected with edaravone(10 mg/kg), once every 12 h, for 3 days. Rats in the IR group and control group were intraperitoneally injected with saline, with the same method and frequency as the rats in the edaravone-treated IR group. In IR group and edaravone-treated IR group, samples of flaps were harvested after reperfusion of the flaps for 24 h. In the control group, samples of flaps were harvested 34 h after creation of the flaps. The content of malondialdehyde(MDA) and activity of superoxide dismutase(SOD) were determined, and changes in organizational structure and infiltration of inflammatory cells were observed by hematoxylin-eosin(HE) staining, apoptotic cells of vascular wall were marked by terminal deoxynucleotidyl transferase-mediated d UTP nick-end labeling(TUNEL) assay, and the apoptotic rate of cells in vascular wall was calculated. The ultrastructural changes of vascular endothelial cells were observed by transmission electron microscopy(TEM). Seven days after the operation, we calculated the flap viability of each group, and marked vessels of flaps by immunohistochemical staining for calculating the average number of subcutaneous vessels. The results showed that the content of MDA, the number of multicore inflammatory cells and apoptotic rate of cells in vascular wall in the edaravone-treated IR group were significantly lower than those in the IR group. The activity of SOD, flap viability and average number of subcutaneous vessels in the edaravone-treated IR group were significantly higher than those in the IR group. All the differences were statistically significant. The ultrastructure injury of vascular endothelial cells in the edaravone-treated IR group was slighter than that in IR group. It was concluded that edaravone can significantly enhance IR flap viability and protect flap vessels, which is related to scavenging oxygen free radicals, reducing the consumption of SOD, reducing the extent of lipid peroxidation and inflammation, and protecting functional structure of vessels in the early stages of reperfusion.展开更多
Objective: To evaluate the antioxidant and antidiabetic activities of Sutherlandia montana E. Phillips & R.A. Dyer leaf extracts using the in vitro model.Methods: The antioxidant activities of aqueous, decoction, ...Objective: To evaluate the antioxidant and antidiabetic activities of Sutherlandia montana E. Phillips & R.A. Dyer leaf extracts using the in vitro model.Methods: The antioxidant activities of aqueous, decoction, ethanol and hydro-ethanol extracts of the plant were determined using seven different assays; the antidiabetic potential was evaluated through the inhibition of key carbohydrate hydrolysing enzymes(aamylase and a-glucosidase), while the modes of the enzymes inhibition were assessed using enzyme kinetic analysis.Results: The ethanol extract exhibited the best scavenging activity(IC_(50): 0.47, 0.36,0.20, 0.29 and 0.01 mg/m L) against the tested radicals like 1,1-diphenyl-2-picrylhydrazyl,2, 20-azinobis(3-ethylbenzothiazoline-6-sulfonic acid), nitric oxide, hydroxyl and superoxide anion, respectively. It also showed the best reducing power efficiency when compared with the standard(silymarin), while the decoction extract displayed the strongest metal chelating potential(IC_(50): 0.71 mg/m L). The ethanol(IC_(50): 5.52 mg/m L)and decoction(IC_(50): 0.05 mg/m L) extracts exhibited mild and strong inhibitory effects on the specific activities of a-amylase and a-glucosidase respectively, through an uncompetitive and non-competitive mode of action.Conclusions: The observed properties might be linked to the presence of active principles as shown by the results of the phytochemical analyses of the extracts. This research has validated the folkloric application of Sutherlandia montana as a potential antidiabetic agent, which is evident from the inhibition of specific activities of key enzymes involved in carbohydrate metabolism.展开更多
The co-oxidation of As(Ⅲ) and Fe(Ⅱ) in acidic solutions by pressured oxygen was studied under an oxygen pressure between 0.5 and 2.0 MPa at a temperature of 150℃. It was confirmed that without Fe(Ⅱ) ions, As(Ⅲ) i...The co-oxidation of As(Ⅲ) and Fe(Ⅱ) in acidic solutions by pressured oxygen was studied under an oxygen pressure between 0.5 and 2.0 MPa at a temperature of 150℃. It was confirmed that without Fe(Ⅱ) ions, As(Ⅲ) ions in the solutions are virtually non-oxidizable by pressured oxygen even at a temperature as high as 200℃ and an oxygen pressure up to 2.0 MPa. Fe(Ⅱ) ions in the solutions did have a catalysis effect on the oxidation of As(Ⅲ), possibly attributable to the production of such strong oxidants as hydroxyl free radicals (OH ) and Fe(Ⅳ) in the oxidation process of Fe(Ⅱ). The effects of such factors as the initial molar ratio of Fe(Ⅱ)/As(Ⅲ), initial pH value of the solution, oxygen pressure, and the addition of radical scavengers on the oxidation efficiencies of As(Ⅲ) and Fe(Ⅱ) were studied. It was found that the oxidation of As(Ⅲ) was limited in the co-oxidation process due to the accumulation of the As(Ⅲ) oxidation product, As(Ⅴ), in the solutions.展开更多
Radiation-induced reduction of chromium(Ⅵ)(Cr(Ⅵ) by ,γ-irradiation was studied with an initial concentration of 42 mg/L in aqueous solutions. Several factors which might affect the reduction of Cr(Ⅵ) to Cr...Radiation-induced reduction of chromium(Ⅵ)(Cr(Ⅵ) by ,γ-irradiation was studied with an initial concentration of 42 mg/L in aqueous solutions. Several factors which might affect the reduction of Cr(Ⅵ) to Cr(Ⅲ) were examined, pH of aqueous solution affects the reduction efficiency significantly. Acidic condition of aqueous solution accelerates the process. At pH 2, a reduction of 86.2% was achieved with the absorbed dose of 15 kGy, while, with the same dose, at pH 5 and 7, the reduction ofCr (Ⅵ) were only 36.3% and 22.2%, respectively. Ethanol (0.1% in V:V) and sodium carbonate (1 mmol/L) were added into the solution respectively as relatively non-toxic hydroxyl radical scavengers. Reduction rate increased greatly in the presence of ethanol at each pH. Reduction efficiency of Cr(Ⅵ) was enhanced in neutral condition with the addition of sodium carbonate, however, no enhancement was found in acidic condition. The reduction of Cr(Ⅵ) was restrained when the solution was saturated with oxygen; however, the restraint was not significant.展开更多
Four polyphenols were isolated and purified from a brown alga </span><i><span style="font-family:Verdana;">Eisenia arborea</span></i><span style="font-family:Verdana;&qu...Four polyphenols were isolated and purified from a brown alga </span><i><span style="font-family:Verdana;">Eisenia arborea</span></i><span style="font-family:Verdana;">. These phlorotannin compounds showed strong radical scavenging and some enzyme inhibitory activities. All of the compounds showed strong antioxidative, acetylcholinesterase and butyrylcholinesterase inhibitory, and tyrosinase inhbibitory activities at 100 μg/mL. Dieckol and PFF inhibited butyrylcholinesterase, a new target for the treatment of Alzheimer’s disease, very strongly even at 10 μg/mL</span></span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> more strongly than AChE. These two compounds also effectively inhibited tyrosinase. These results support the potential of developing natural antioxidants and antidementia agents from the brown alga.展开更多
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 ...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.展开更多
基金Supported by A Grant from the University of Bologna (Ricerca Fondamentale Orientata)
文摘AIM:To investigate the effects of the free radical scavenger bis(1-hydroxy-2,2,6,6-tetramethyl-4-piperidinyl) decandioate(IAC) in the dextran sodium sulphate(DSS) experimental model of ulcerative colitis.METHODS:Colitis was induced in Sprague Dawley male rats by administration of 5% DSS in drinking water.IAC(30 mg/kg,lipophilic or hydrophilic form) was administered daily(orally or ip) for 6 d until sacrifice.Colonic damage was assessed by means of indirect(Disease Activity Index score) and direct measures(macroscopic and microscopic scores) and myeloperoxidase(MPO)activity.Neutrophil infiltration within the tissue and glutathione S-transferase activity were also investigated.RESULTS:DSS-induced colitis impaired body weight gain and markedly increased all inflammatory parameters.Six-day treatment with lipophilic IAC significantly reduced intestinal damage caused by inflammation,induced a down-regulation in MPO activity(0.72 ± 0.12 and 0.45 ± 0.12 with lipophilic IAC po and ip,respectively,vs 1.10 ± 0.27 in untreated DSS colitis animals) and minimized DSS-induced neutrophil infiltration,while hydrophilic IAC administered orally did not ameliorate DSS-induced damage.CONCLUSION:These results support the hypothesis that reactive oxygen metabolites contribute to inflammation and that the radical scavenger IAC has therapeutic potential in inflammatory bowel disease.
文摘Photoelectrocatalytic degradation performance of quinoline in saline water was investigated using a new-designed continuous flow three-dimensional electrode-packed bed photocatalytic reactor. It is interesting to find that chloride ion has an obvious enhancement effect rather than a scavenging effect on the photoelectrocatalytic degradation of quinoline, and create a kinetic synergetic effect in the photoelectrocatalytic reactor.
基金Supported by 2023 Zhanjiang Non-funded Science and Technology Research Plan(2023B01023)2022 University-level Education and Teaching Reform Project of Lingnan Normal University(LingShiJiaoWu2022154).Junxia SONG,bachelor degree,experimenter,research fields:physical geography.
文摘[Objectives]To study the optimum conditions of solid fermentation of natto with antioxidant function as an index.[Methods]Single factor experiment and orthogonal experiment were designed to study the effects of temperature,time,initial pH and inoculum amount on the antioxidant activity of natto solid fermentation.The optimum conditions of natto solid fermentation were determined and the antioxidant ac-tivity of natto extract was compared.[Results]The optimal fermentation conditions were as follows:temperature 32℃,initial pH 7.0,inocu-lation amount 8%,fermentation time 32 h.The hydroxyl radical scavenging rate of natto solid fermentation crude extract was the highest,which was 82.7%.The optimized nato fermentation extract showed stronger scavenging ability for-OH and O,:,and showed obvious dose-effect relationship.ICso was 3.63 and 4.24 mg/mL,respectively,and the scavenging efficiency was 1.3 and 1.9 times higher than that of the unoptimized fermentation extract,respectively.[Conclusions]Natto is rich in nattokinase and other functional factors,and its antioxidant ac-tivity can be improved by optimizing fermentation technology,so that natto products can be widely used,including cosmetic raw materials,nat-to skin care soap,health food and medicine,etc.,and have a broader development prospect.
基金supported by Intramural Foundation from Wenzhou Medical College
文摘Four naturally rare 5,6,7-trimethoxy-2,3-cis-dihydroflavonols (3-6) and two 5,6,7-trimethoxy-2,3-trans-dihydroflavonols (7-8) were designed and synthesized. Their antioxidative properties were evaluated by way of examining their scavenging capacities towards DPPH and O2^*- free radicals, as well as by measuring their inhibitory ability against LPO. Both the 2,3-trans and the 2,3- cis conformers exhibited certain quenching abilities to DPPH and O2^*- radicals, while most of the synthetic dihydroflavonols demonstrated remarkable inhibition to LPO.
基金Supported by the Science and Technique Foundation of Jilin Province, China(No20020503-2)
文摘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%.
基金supported by grant no.90(0039)/04/EMR-II of Council of Scientific and Industrial Research,Government of India,New Delhi.Anuradha Sehrawat has been a Research Associate of Department of Biotechnology,Government of India,during the period of this study。
文摘The flower of Butea monosperma(Lam.)(Fabaceae)has been used in traditional Indian medicine in the treatment of many ailments including liver disorders.To understand the pharmacological basis of its beneficial effects,the extracts of dried flowers in water,methanol,butanol,ethyl acetate and acetone were evaluated for free radical scavenging and pro-apoptotic activities in cell cultures(human hepatoma Huh-7 cell line and immortalized AML-12 mouse hepatocytes).Butrin and butein-the active constituents of flower extracts-were used as reference molecules.The levels of cell injury markers like lactate dehydrogenase,glutathione and lipid peroxidation and primary antioxidant enzymes glutathione S-transferase and catalase were also measured.The aqueous and butanolic extracts exhibited better 2,2-diphenyl-1-picrylhydrazyl scavenging and cytotoxic activities in hepatoma cells than in immortalized hepatocytes.Interestingly,butein inhibited 2,2-diphenyl-1-picrylhydrazyl radical better than butrin.The aqueous and butanolic extracts were further investigated for hepatoprotection against carbon tertrachloride-induced biochemical changes and cell death.Both extracts,just as butrin and butein,significantly reversed the cellular glutathione levels and lipid peroxidation,and glutathione–S-transferase activity.Lactate dehydrogenase leakage and cell death were also prevented.However,only butein revived the catalase activity.Thus,the butein content of Butea monosperma flower extracts is important for free radical scavenging activity,apoptotic cell death and protection against oxidative injury in hepatic cells.
文摘BACKGROUND: The fluidity of cell membrane can be affected by various factors. Many experiments have confirmed that the ischemia/reperfusion of organic tissue can increase the contents of free radicals, which lead to high rigidity and low fluidity of cell membrane, and the conditions can be changed by Chuanxiongqin. OBJECTIVE: To observe the effect and mechanism of Chuanxiongqin hydrochloride on the fluidity of brain cell membrane in rat models of ischemia/reperfusion. DESIGN: A completely randomized controlled animal trial. SETTINGS: Institute of Brain Sciences; Department of Physiology, Medical College, Datong University. MATERIALS: Twenty male grade Ⅰ Wistar rats of 170-220 g were randomly divided into model group (n =10) and control group (n =10). Chuanxiongqin hydrochloride (molecular mass was 172.2) was purchased from the National Institute for the Control of Pharmaceutical and Biological Products (batch number: 0817-9803); Spin labelers: 5-doxyl-stearlic acid methylester (5DS), 16-doxyl-stearlic acid methylester (16DS), xanthine, xanthine oxidase (XOD) and 5,5-dimeth-1-pyrroline- N-oxide (DMPO) from Sigma Company; Bruker ESP 300 electron paramagnetic resonance (EPR) spectrometer by Bruker Company (Germany). METHODS: The experiments were carried out in the State Key Laboratory of Natural and Biomimetic Drugs, Peking University from June 2001 to July 2002. In the model group, rats were made into models of cerebral ischemia by 30-minute ligation and 2-hour reperfusion of common carotid arteries; The rats in the control group were not made into models. The order parameter (S) and rotational correlation time (τc) were detected with the ESR spectrometer by means of spin labeling. The greater the S and τc, the smaller the fluidity. Meanwhile, the clearance rate of free radicals was detected with ESR spin trapping. The measurement data were compared using the t test. MAIN OUTCOME MEASURES: The S, τc and clearance rates of O2 · and OH· free radicals were compared between the model group and control group. RESULTS: The S and τc in the model group [0.738 4±0.003 5; (8.472±0.027)×10-10 s/circle] were obviously different from those in the control group [0.683 9±0.008 3; (7.945±0.082)×10-10 s/circle, t =5.731, 5.918, P < 0.05], which suggested that ischemia/reperfusion injury decreased the fluidity of brain cell membrane. After adding Chuanxiongqin hydrochloride, there were no obvious differences between the model group [0.688 5±0.030 5; (7.886±0.341)×10-10 s/circle] and control group (P > 0.05), indicating that Chuanxiongqin hydrochloride could recover the fluidity of brain cell membrane after ischemia/reperfusion injury close to the level in the normal control group. Chuanxiongqin hydrochloride could directly scavenge the O2 · and OH· free radicals, and the maximal clearance rates were 83.92% and 44.99% respectively. CONCLUSION: Chuanxiongqin hydrochloride increases the fluidity of membrane of ischemia-injured brain cell by scavenging both O2 ·and OH· free radicals.
文摘The static O-H bond parameters including O-H bond length, O-H charge difference, O-H Mulliken population and O-H bond stretching force constant (k) for 17 phenols were calculated by ab initio method HF/6-31G**. In combination with the O-H bond dissociation enthalpies (BDE) of the phenols determined by experiment, it was found that there were poor correlationships between the static O-H bond parameters and O-H BDE. Considering the good correlationship bt tween O-H BDE and logarithm of free radical scavenging rate constant for phenolic antioxidant, it is reasonable to believe that the ineffectiveness of static O-H bond parameters in characterizing antioxidant activity arises from the fact that they cannot measure the O-H BDE.
文摘The synthesis of (±)-5, 6, 7-trioxygenated dihydroflavonols was carried out. All synthetic compounds were passed through superoxide radical scavenging activity in vitro. Compounds 1 e and 1 g exhibited significant bioactivity with the inhibitory rates of 68.1% and 80.9% at 40 μg/mL, respectively.
基金Authors thank to Universidad Autónoma de Tamaulipas for financial support to the project UAT-PFI2017-ACP02 for J.A.Torres-Castillo.
文摘This work aims to determine the phytochemical characterization of the pericarp of Chamaedorea radicalis Mart.fruit as a non-timber product with potential to obtain phytochemicals with potential applications in the industry.Fruit from C.radicalis were grouped in four ripening stages named as S1,S2,S3 and S4,according to maturity;S1 the most unripe stage and S4 the completely ripe stage.Determinations of total phenolic compounds,free radical scavenging activities and total flavonoid contents using spectrophotometric methods were done.Also,the tentative identification of phytochemicals during fruit ripening was done using UPLC-MS-MS.Total phenolic compound(TPC)content ranged from 7.24 to 12.53 mg gallic acid equivalents per gram of fresh weight(mg GAE/g FW).Total flavonoids(TF)contents ranged from 0.163 to 0.23 mg of quercetin equivalents per g FW(mg QE/g FW).Free radical scavenging activity against DPPH and ABTS radicals varied from 40.80 to 53.68 and from 22.29 to 37.76 mmol Trolox equivalents g FW(mmol TE/g FW),respectively.Antioxidant assay in vitro by FRAP(ferric reducing antioxidant power)method showed that S3 was the highest level with antioxidant power while S4 was the lowest with Red ripeness stage showed the lowest contents for all determinations.Mass spectrometry allowed detection of 26 compounds,including phenolics,alkaloids and saponins.Afzelin,Kaempferol 3-neohesperidoside and the four saponins identified were present in all ripeness stages.Preliminary phytochemical identification and the spectrophotometric determinations showed that the pericarp of C.radicalis presented antioxidants and compounds related to alkaloids,phenolics and saponins.The presence and abundance of each phytochemical regarding each ripeness stage should be considered.
基金This research was supported by the Natural Sciences and Engineering Research Council of Canada(NSERC) by Atoka Cranberries Inc.(Manseau,QC,Canada).
文摘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.
基金Supported by the Project of"Striving to Be First-classImproving Weak LinksBuilding Strong Feature"in 2019–Tropical and South China Sea Biological Resources Comprehensive Utilization Program(000301900410)。
文摘[Objectives]To explore the extraction and in vitro antioxidant effects of astragalus polysaccharides(APS)and Ganoderma lucidum mycelia polysaccharides(GLMPS).[Methods]By studying the polysaccharides of the herbal medicinal material Astragalus membranaceus and the fungal medicinal material Ganoderma lucidum mycelia,two polysaccharides were mixed according to different proportions and concentrations by using the principle of traditional Chinese medicine compound combination.The effect of polysaccharides on the scavenging ability of hydroxyl radical system was determined by salicylic acid method.[Results]When the compound ratios of GLMPS and APS were 1∶1,1∶4,1∶5,4∶1,and 5∶1,the scavenging effect of compound polysaccharides was better than that of single-component polysaccharides,and with the increase of concentration,the scavenging effect increased.When the ratio of GLMPS and APS was 5∶1,the hydroxyl radical scavenging rate of the compound polysaccharide reached 59.77%,which was 18.72%higher than that of single GLMPS and 28.58%higher than that of single APS.The scavenging effect of compound polysaccharide is closely related to the compound ratio and concentration.[Conclusions]APS and GLMPS can obtain better hydroxyl radical scavenging ability than single-component polysaccharides through compounding in appropriate proportions.In addition,within a suitable concentration range,as the concentration increases,the scavenging ability also increases.
基金supported by Rashtrsant Tukadoji Maharaj Memorial Fellowship from Rashtrasant Tukadoji Maharaj Nagpur University。
文摘Objective:To examine the effects of hydroalcoholic extract and fractions of Hordeum vulgare Linn.(H.vulgare,Da Mai)on streptozotocin(STZ)-induced diabetic nephropathy in Sprague-Dawley rat models.Methods:The study involved preliminary phytochemical screening of extract and fractions,estimation of secondary metabolites,chromatographic studies using high performance liquid chromatography(HPLC),antioxidant potential using 1,1-diphenyl-2-picrylhydrazyl(DPPH),nitric oxide radical scavenging and reducing power methods along with the determination of potential against diabetic nephropathy in STZ-induced rat models.Results:The phytochemical evaluation of the hydroalcoholic extract of H.vulgare and fractions revealed the presence of various phytoconstituents such as alkaloids,saponins,tannins,flavonoids,and glycosides.The chromatographic analysis indicated the peak complementing marker compound epicatechin and significant antioxidant activity in the extract and aqueous fraction.STZ-induced rats showed abnormal levels of serum albumin,creatinine,total cholesterol,blood urea nitrogen(BUN),and triglycerides,and urine albumin and creatinine,which returned to normal after 8 weeks of treatment with hydroalcoholic extract(400 mg/kg)and aqueous fraction(50 mg/kg)of H.vulgare.Conclusion:Hydroalcoholic extract(400 mg/kg)and aqueous fraction(50 mg/kg)of H.vulgare have significant antioxidant potential and positive effects on diabetic nephropathy.The fractionation and optimization increase the concentration of polyphenols in aqueous extract,causing a decrease in the dose required for effects against diabetic nephropathy.
文摘Plant polyphenols are reported to have bioactive properties, which may be used for protection against diseases. Therefore, the aim of this research was to investigate the antioxidant activities of a pomegranate tannin polyphenol compound, punicalagin and pomegranate juice. The presence of punicalagin in pomegranate husk (US) and pomegranate juice (US & UK) was compared with a punicalagin standard using high performance liquid chromatography (HPLC) and liquid chromatography-mass spectroscopy (LC-MS) which are highly sensitive and selective analytical methods for the separation and identification of phenolic compounds and anthocyanins. Antioxidant mechanisms involving DPPH radical scavenging activity, hydrogen peroxide scavenging, ferrous chelating and reducing ability were also studied on pomegranate juice and standard punicalagin. The present study shows a high degree of similarity of HPLC and LC-MS results between the punicalagin commercial standard (Sigma Aldrich) and US pomegranate husk extracted with methanol. In contrast, in the methanol juice extract obtained from US and UK, higher hydrogen peroxide scavenging activity was achieved by 0.1 mg/ml from both punicalagin and pomegranate juice when compared with butylated hydroxytoluene (BHT) or trolox (p ≤ 0.01). Punicalagin and pomegranate juice exhibited ferrous chelating ability significantly lower than Ethylenediaminetetraacetic acid. These findings confirmed that punicalagin was present in pomegranate husk compared to pomegranate juice, as measured using a punicalagin standard. The antioxidant mechanism experiments concluded that, the pomegranate juice has a significantly higher radical scavenging activity in comparison with punicalagin (p ≤ 0.01). However, punicalagin showed significant ferrous chelating activity and reducing power ability in a dose-dependent manner as compared with pomegranate juice.
基金supported by Henan Provincial Key Scientific and Technological Project of China(No.132102310088)
文摘The purpose of the experiment was to study the efficacy of edaravone in enhancing flap viability after ischemia/reperfusion(IR) and its mechanism. Forty-eight adult male SD rats were randomly divided into 3 groups: control group(n=16), IR group(n=16), and edaravone-treated IR group(n=16). An island flap at left lower abdomen(6.0 cm×3.0 cm in size), fed by the superficial epigastric artery and vein, was created in each rat of all the three groups. The arterial blood flow of flaps in IR group and edaravone-treated IR group was blocked for 10 h, and then the blood perfusion was restored. From 15 min before reperfusion, rats in the edaravone-treated IR group were intraperitoneally injected with edaravone(10 mg/kg), once every 12 h, for 3 days. Rats in the IR group and control group were intraperitoneally injected with saline, with the same method and frequency as the rats in the edaravone-treated IR group. In IR group and edaravone-treated IR group, samples of flaps were harvested after reperfusion of the flaps for 24 h. In the control group, samples of flaps were harvested 34 h after creation of the flaps. The content of malondialdehyde(MDA) and activity of superoxide dismutase(SOD) were determined, and changes in organizational structure and infiltration of inflammatory cells were observed by hematoxylin-eosin(HE) staining, apoptotic cells of vascular wall were marked by terminal deoxynucleotidyl transferase-mediated d UTP nick-end labeling(TUNEL) assay, and the apoptotic rate of cells in vascular wall was calculated. The ultrastructural changes of vascular endothelial cells were observed by transmission electron microscopy(TEM). Seven days after the operation, we calculated the flap viability of each group, and marked vessels of flaps by immunohistochemical staining for calculating the average number of subcutaneous vessels. The results showed that the content of MDA, the number of multicore inflammatory cells and apoptotic rate of cells in vascular wall in the edaravone-treated IR group were significantly lower than those in the IR group. The activity of SOD, flap viability and average number of subcutaneous vessels in the edaravone-treated IR group were significantly higher than those in the IR group. All the differences were statistically significant. The ultrastructure injury of vascular endothelial cells in the edaravone-treated IR group was slighter than that in IR group. It was concluded that edaravone can significantly enhance IR flap viability and protect flap vessels, which is related to scavenging oxygen free radicals, reducing the consumption of SOD, reducing the extent of lipid peroxidation and inflammation, and protecting functional structure of vessels in the early stages of reperfusion.
基金the research committee of the University of the Free State, Qwaqwa Campus for financing the study with Grant number 211527604
文摘Objective: To evaluate the antioxidant and antidiabetic activities of Sutherlandia montana E. Phillips & R.A. Dyer leaf extracts using the in vitro model.Methods: The antioxidant activities of aqueous, decoction, ethanol and hydro-ethanol extracts of the plant were determined using seven different assays; the antidiabetic potential was evaluated through the inhibition of key carbohydrate hydrolysing enzymes(aamylase and a-glucosidase), while the modes of the enzymes inhibition were assessed using enzyme kinetic analysis.Results: The ethanol extract exhibited the best scavenging activity(IC_(50): 0.47, 0.36,0.20, 0.29 and 0.01 mg/m L) against the tested radicals like 1,1-diphenyl-2-picrylhydrazyl,2, 20-azinobis(3-ethylbenzothiazoline-6-sulfonic acid), nitric oxide, hydroxyl and superoxide anion, respectively. It also showed the best reducing power efficiency when compared with the standard(silymarin), while the decoction extract displayed the strongest metal chelating potential(IC_(50): 0.71 mg/m L). The ethanol(IC_(50): 5.52 mg/m L)and decoction(IC_(50): 0.05 mg/m L) extracts exhibited mild and strong inhibitory effects on the specific activities of a-amylase and a-glucosidase respectively, through an uncompetitive and non-competitive mode of action.Conclusions: The observed properties might be linked to the presence of active principles as shown by the results of the phytochemical analyses of the extracts. This research has validated the folkloric application of Sutherlandia montana as a potential antidiabetic agent, which is evident from the inhibition of specific activities of key enzymes involved in carbohydrate metabolism.
基金financially supported by the National Natural Science Foundation of China (No. 51574285)
文摘The co-oxidation of As(Ⅲ) and Fe(Ⅱ) in acidic solutions by pressured oxygen was studied under an oxygen pressure between 0.5 and 2.0 MPa at a temperature of 150℃. It was confirmed that without Fe(Ⅱ) ions, As(Ⅲ) ions in the solutions are virtually non-oxidizable by pressured oxygen even at a temperature as high as 200℃ and an oxygen pressure up to 2.0 MPa. Fe(Ⅱ) ions in the solutions did have a catalysis effect on the oxidation of As(Ⅲ), possibly attributable to the production of such strong oxidants as hydroxyl free radicals (OH ) and Fe(Ⅳ) in the oxidation process of Fe(Ⅱ). The effects of such factors as the initial molar ratio of Fe(Ⅱ)/As(Ⅲ), initial pH value of the solution, oxygen pressure, and the addition of radical scavengers on the oxidation efficiencies of As(Ⅲ) and Fe(Ⅱ) were studied. It was found that the oxidation of As(Ⅲ) was limited in the co-oxidation process due to the accumulation of the As(Ⅲ) oxidation product, As(Ⅴ), in the solutions.
文摘Radiation-induced reduction of chromium(Ⅵ)(Cr(Ⅵ) by ,γ-irradiation was studied with an initial concentration of 42 mg/L in aqueous solutions. Several factors which might affect the reduction of Cr(Ⅵ) to Cr(Ⅲ) were examined, pH of aqueous solution affects the reduction efficiency significantly. Acidic condition of aqueous solution accelerates the process. At pH 2, a reduction of 86.2% was achieved with the absorbed dose of 15 kGy, while, with the same dose, at pH 5 and 7, the reduction ofCr (Ⅵ) were only 36.3% and 22.2%, respectively. Ethanol (0.1% in V:V) and sodium carbonate (1 mmol/L) were added into the solution respectively as relatively non-toxic hydroxyl radical scavengers. Reduction rate increased greatly in the presence of ethanol at each pH. Reduction efficiency of Cr(Ⅵ) was enhanced in neutral condition with the addition of sodium carbonate, however, no enhancement was found in acidic condition. The reduction of Cr(Ⅵ) was restrained when the solution was saturated with oxygen; however, the restraint was not significant.
文摘Four polyphenols were isolated and purified from a brown alga </span><i><span style="font-family:Verdana;">Eisenia arborea</span></i><span style="font-family:Verdana;">. These phlorotannin compounds showed strong radical scavenging and some enzyme inhibitory activities. All of the compounds showed strong antioxidative, acetylcholinesterase and butyrylcholinesterase inhibitory, and tyrosinase inhbibitory activities at 100 μg/mL. Dieckol and PFF inhibited butyrylcholinesterase, a new target for the treatment of Alzheimer’s disease, very strongly even at 10 μg/mL</span></span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> more strongly than AChE. These two compounds also effectively inhibited tyrosinase. These results support the potential of developing natural antioxidants and antidementia agents from the brown alga.
基金supported by the National Technologies R&D Program of China (2006BAD01A02)the Excellent Medium-Youth Scientist Scientific Research Reward Fundation of Shandong Province, China (BS2009NY036)the Youth Science and Technology Creative Fundation Item of Shandong Agricultural University, China
文摘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.