Objective The SOD, POD and APX enzyme activities of tetraploid lines and diploid control line of Chrysanthemum cinerariifolium in test-tube and field were determined in order to provide a reference for the selective b...Objective The SOD, POD and APX enzyme activities of tetraploid lines and diploid control line of Chrysanthemum cinerariifolium in test-tube and field were determined in order to provide a reference for the selective breeding of high resistance good tetraploid varieties of C. cinerariifolium. Method The SOD, POD and APX activities of each sample were determined. Every material should have 3 replicates which been determined and calculated mean value to analyze. Result The various kinds of antioxidase activities in protective enzyme system of tetraploid lines were increased generally in comparison with that of diploid control line. And there is certain relativity between the samples in field and in test-tube of these lines. Conclusion The antioxidase activities of each line in test-tube could be considered as reference index to screen high resistance good tetraploid varieties of C. cinerariifolium.展开更多
To study the antioxidant constituents from the stems of Dendrobium nobile, and to discuss theft structure-activity relationship. Compounds were isolated from a 60% ethanolic extract by various chromatographic techniqu...To study the antioxidant constituents from the stems of Dendrobium nobile, and to discuss theft structure-activity relationship. Compounds were isolated from a 60% ethanolic extract by various chromatographic techniques and were identified by spectral analysis. The antioxidant activities of compounds were evaluated by DPPH free radical scavenging assay. Five phenanthrenes and four lignans were obtained from the active fractions ofD. nobile. Their structures were identified as fimbriatone (1), confusarin (2), flavanthrinin (3), 2,5-dihydroxy-4,9-dimethoxyphenanthrene (4), 3,7-dihydroxy-2,4-dimethoxyphenanthrene (5), syringaresinol (6), pinoresinol (7), medioresinol (8) and lirioresinol-A (9), respectively. Compounds 2 and 6 exhibited more potent DPPH scavenging activities than vitamin C. All the above compounds were reported from this plant for the first time, and compounds 3, 4 and 9 were reported for the first time from the genus of Dendrobiurn. For all phenanthrenes and lignans, an electron-donating methoxyl group in the ortho position to the phenolic hydroxyl group exhibits enhanced antioxidant activities.展开更多
The molecular structure and radical scavenging activity of three novel antioxidants from Lespedeza Virgata, lespedezavirgatol, lespedezavirgatal, and lespedezacoumestan, have been studied using density functional theo...The molecular structure and radical scavenging activity of three novel antioxidants from Lespedeza Virgata, lespedezavirgatol, lespedezavirgatal, and lespedezacoumestan, have been studied using density functional theory with the B3LYP and BhandHLYP methods. The optimized geometries of neutral, radical cation, radical and anion forms were obtained at the B3LYP/6-31G(d) level, in which it was found that all the most stable conformations contain intramolecular hydrogen bonds. The same results were obtained from the MP2 method. The homolytic O-H bond dissociation enthalpy and the adiabatic ionization potential of neutral and anion forms for the three new antioxidants and adiabatic electron affinity and H-atom affinity for hydroxyl radical, superoxide anion radical, and hydrogen peroxide radical were determined both in gas phase and in aqueous solution using IEF-PCM and CPCM model with UAHF or Bondi cavity. The antioxidant activities and reactive oxygen species scavenging mechanisms were then discussed, and the results obtained from different methods are consistent. Furthermore, the antioxidant activities are consistent with the experimental findings of the compounds under investigation.展开更多
Mackerel (Pneumatophorus japonicus) proteins were hydrolyzed by five proteases: trypsin, papain, neutrase, acid protease, and flavourzyme. The hydrolysate treated by neutrase exhibited the highest antioxidant activ...Mackerel (Pneumatophorus japonicus) proteins were hydrolyzed by five proteases: trypsin, papain, neutrase, acid protease, and flavourzyme. The hydrolysate treated by neutrase exhibited the highest antioxidant activity. Response surface methodology (RSM) was employed to optimize the hydrolysis conditions in an effort to obtain a mackerel protein hydrolysate (MPH) with the highest DPPH radical scavenging activity. The MPH was fractioned using a series of ultrafiltration membranes and five fractions, namely, MPH-I (〉10 kDa), MPH-II (10-2.5 kDa), MPH-III (1-2.5 kDa), MPH-IV (0.4-1 kDa), and MPH-V (below 0.4 kDa), were obtained. DPPH radical scavenging activity, reducing power, hydroxyl radical scavenging activity, and the lipid peroxidation inhibition capability of these fractions were evaluated. The fractions in molecular weights 〈2.5 kDa (MPH-III, MPH-IV, and MPH-V), which occupied 93.4% of the total fractions, showed the strongest antioxidant activity; and the antioxidant activities of the three fractions are similar to each other. Using SP Sephadex C-25 and Sephadex G-25 columns, eight fractions were obtained from the MPH (〈2.5 kDa). The isolated peptide I (1 664 kDa) displayed the highest DPPH radical scavenging activity. Therefore, MPH is a potential source of antioxidant peptides.展开更多
Heterogeneous Fenton-like process using fly ash as a catalyst was studied to degrade n-butyl xanthate form aqueous solution. The different reaction parameters on the degradation efficiency of the process were investig...Heterogeneous Fenton-like process using fly ash as a catalyst was studied to degrade n-butyl xanthate form aqueous solution. The different reaction parameters on the degradation efficiency of the process were investigated. The fly ash/H2O2 catalyst possesses a high oxidation activity for n-butyl xanthate degradation in aqueous solution. It is found that both the dosage of catalyst and initial solution pH significantly affect the n-butyl xanthate conversion efficient. The results indicate that by using 1.176 mmol/L H2O2 and 1.0 g/L fly ash catalyst with mass fraction of 4.14% Fe(III) oxide at pH 3.0, almost 96.90% n-butyl xanthate conversion and over 96.66% COD removal can be achieved within 120 min with heterogeneous catalysis by fly ash. CS2 as an intermediate of n-butyl xanthate oxidation. Finally, it is demonstrated that the fly ash/H2O2 catalytic oxidation process can be an efficient method for the treatment of n-butyl xanthate containing wastewater.展开更多
We evaluated the hydroxyl and alkyl-oxy radical scavenging activity of instant coffee using an electron spin resonance (ESR) spin-trapping method, which was based the spin-trapping reagent 5-(2,2-dimethy-l,3-propox...We evaluated the hydroxyl and alkyl-oxy radical scavenging activity of instant coffee using an electron spin resonance (ESR) spin-trapping method, which was based the spin-trapping reagent 5-(2,2-dimethy-l,3-propoxycyclophosphoryl)-5-methyl-l-pyrroline N-oxide (CYPMPO). In this method, very pure hydroxyl and alkyl-oxy radicals were generated by illuminating a phosphate buffer solution containing hydrogen peroxide and 2,2'-azobis (2-amidinopropane) dihydrochloride with a Hg-Xe arc lamp. The ESR adduct signal was sensitive and very stable. We concluded that instant coffee has high hydroxyl radical and alkyl-oxy radical scavenging activity.展开更多
Fe-ZSM-5 catalysts modified by Cu and Ce by aqueous solution ion-exchange and incipient wetness impregnation methods were tested in the selective catalytic reduction of NO_(x) with NH_(3).A variety of characterization...Fe-ZSM-5 catalysts modified by Cu and Ce by aqueous solution ion-exchange and incipient wetness impregnation methods were tested in the selective catalytic reduction of NO_(x) with NH_(3).A variety of characterization techniques(NH_(3)-SCO,BET,XRD,XPS,UV-Vis,NH_(3)-TPD,H_(2)-TPR)were used to explore the changes of the active sites,acid sites and pore structure of the catalyst.It was found that the dispersion of active Cu species and Fe species had great influences on the catalytic activity in the whole catalytic process.The Cu doping into the Fe-ZSM-5 catalyst produced new active species,isolated Cu ions and CuO particles,resulting in the improved low-temperature catalytic activity.However,the NH_(3) oxidation was enhanced,and part of the Fe^(3+)active sites and more Brønsted acidic sites in the catalyst were occupied by Cu species,which causes the decrease of the high-temperature activity.The recovery of hightemperature activity could be attributed to the recovery of active Cu species and Fe species promoted by Ce and the promotion of active species dispersion.The results provide theoretical support for adjusting the active window of Febased SCR catalyst by multi-metal doping.展开更多
Fish skin collagen hydrolysates (FSCH) were prepared from walleye pollock (Theragra chalcogramrna) using a mixture of enzymes, namely trypsin and flavourzyme. The degree of hydrolysis of the skin collagen was 27.3...Fish skin collagen hydrolysates (FSCH) were prepared from walleye pollock (Theragra chalcogramrna) using a mixture of enzymes, namely trypsin and flavourzyme. The degree of hydrolysis of the skin collagen was 27.3%. FSCH was mainly composed of low-molecular-weight peptides and the relative proportion of 〈1000Da fraction was 70.6%. Free radical and oxygen species scavenging activities of FSCH were investigated in four model systems, including diphenylpicrylhy-drazyl radical (DPPH), superoxide anion radical, hydroxyl radical and hydrogen peroxide model, and compared with that of a native antioxidant, reduced glutathione (GSH). FSCH was also evaluated by water-absorbing and water-holding capacity. The results showed that FSCH was able to scavenge free radical and oxygen species significantly and to enhance water-absorbing and water-holding capacity remarkably. Therefore FSCH may have potential applications in the medicine and food industries.展开更多
Background In type 2 diabetes mellitus (T2DM), high-density lipoprotein (HDL) impairs its anti-atherogenic properties and even develops to a pro-inflammatory and pro-atherogenic phenotype because of abnormal compo...Background In type 2 diabetes mellitus (T2DM), high-density lipoprotein (HDL) impairs its anti-atherogenic properties and even develops to a pro-inflammatory and pro-atherogenic phenotype because of abnormal compositions and modifications. In this study, we ex- amined the effects and the related mechanisms of glycation of HDL on the proliferation and migration of vascular smooth muscle cells (VSMCs). Methods & Results Glycated HDL (G-HDL) was modified with D-glucose (25 mmol/L) in vitro. Diabetic HDL (D-HDL) was isolated from T2DM patients. Rat VSMCs were isolated from the thoracic aortas. Human VSMCs were obtained from ScienCell Research Laboratories. Alpha-actin was detected through immunofiuorescence. VSMC proliferation was assayed by Cell Count. VSMC migration was determined by transwell chamber and scratch-wound assay. Intracellular reactive oxygen species (ROS) was detected based on ROS-medi- ated 2',7'-dichlorofluorescein (DCFH-DA) fluorescence. Compared to native HDL (N-HDL), G-HDL remarkably promoted VSMC prolif- eration and migration in the dose and time-dependent manners. In addition, G-HDL enhanced ROS generation in VSMCs. However, the ROS scavenger, N-acetylcysteine, efficiently decreased ROS production and subsequently inhibited the proliferation of VSMCs induced by G-HDL. Similarly, D-HDL from T2DM patients also promoted ROS release and VSMC proliferation and migration. Conclusions HDL either glycated in vitro or isolated from T2DM patients triggered VSMC proliferation, migration, and oxidative stress. These results might partly interpret the higher morbidity of cardiovascular disease in T2DM patients.展开更多
The toxic mechanism of herbicide butachlor to induce extremely high lethality in marine flatfish flounder, Paralichthys Olivaceus, was analyzed by histopathological examination, antioxidant enzymes activities and ATP ...The toxic mechanism of herbicide butachlor to induce extremely high lethality in marine flatfish flounder, Paralichthys Olivaceus, was analyzed by histopathological examination, antioxidant enzymes activities and ATP content assay. Histopathological examination of gill, liver and kidney of exposed fishes showed that gill was a target organ of butachlor. The butachlor seriously impaired the respiration of gills by a series of lesions such as edema, lifting and detachment of lamellar epithelium, breakdown of pillar cells, and blood congestion. The dysfunction of gill respiration caused suffocation to the exposed flounder with extremely high acute lethality. Antioxidant enzyme activity assay of the in vitro cultured flounder gill (FG) ceils exposed to butachlor indicated that butachlor markedly inhibited the antioxidant enzyme activities of Superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX). Furthermore, along with the decline of antioxidant enzyme activities, ATP content in the exposed FG cells decreased, too. This infers that the oxidative stress induced by butachlor can inhibit the production of cellular ATP. Similar decrease of ATP content was also observed in the exposed flounder gill tissues. Taken together, as in FG cells, butachlor possibly induced a short supply of ATP in pillar cells by inhibiting the antioxidant enzyme activities and then affecting the contractibility of the pillar cells, which in turn resulted in the blood congestion and suffocation of exposed flounder.展开更多
A pilot-scale modified carbon source division anaerobic anoxic oxic(AAO) process with pre-concentration of returned activated sludge(RAS) was proposed in this study for the enhanced biological nutrient removal(BNR) of...A pilot-scale modified carbon source division anaerobic anoxic oxic(AAO) process with pre-concentration of returned activated sludge(RAS) was proposed in this study for the enhanced biological nutrient removal(BNR) of municipal wastewater with limited carbon source. The influent carbon source was fed in step while a novel RAS pre-concentration tank was adopted to improve BNR efficiency, and the effects of an influent carbon source distribution ratio and a RAS pre-concentration ratio were investigated. The results show that the removal efficiency of TN is mainly influenced by the carbon source distribution ratio while the TP removal relies on the RAS pre-concentration ratio. The optimum carbon source distribution ratio and RAS pre-concentration ratio are 60% and 50%, respectively, with an inner recycling ratio of 100% under the optimum steady operation of pilot test, reaching an average effluent TN concentration of 9.8 mg·L-1with a removal efficiency of 63% and an average TP removal efficiency of 94%. The mechanism of nutrient removal is discussed and the kinetics is analyzed. The results reveal that the optimal carbon source distribution ratio provides sufficient denitrifying carbon source to each anoxic phase, reducing nitrate accumulation while the RAS pre-concentration ratio improves the condition of anaerobic zone to ensure the phosphorus release due to less nitrate in the returned sludge. Therefore, nitrifying bacteria, denitrifying bacteria and phosphorus accumulation organisms play an important role under the optimum condition, enhancing the performance of nutrient removal in this test.展开更多
On the basis of study on the mechanism of action of sulfonylurea herbicides, nine sulfonylurea derivatives of iso-{xazolidinone} were designed and synthesized. The structures of these compounds were confirmed by means...On the basis of study on the mechanism of action of sulfonylurea herbicides, nine sulfonylurea derivatives of iso-{xazolidinone} were designed and synthesized. The structures of these compounds were confirmed by means of IR, MS, NMR and elemental analysis. The results of preliminary active tests indicate that the compounds have some herbicidal activity. The structure-activity relationship was also studied.展开更多
Polysaccharides of Tricholoma matsutake Sing. were extracted with boilingwater, followed by precipitating with ethanol. Two membranes of different molecular weight cut-off, namely, 30 kD and 10 kD were chosen with ult...Polysaccharides of Tricholoma matsutake Sing. were extracted with boilingwater, followed by precipitating with ethanol. Two membranes of different molecular weight cut-off, namely, 30 kD and 10 kD were chosen with ultrafiltration. The antioxidant activity of the purification polysaccharides was evaluated by various antioxidant assay, including DPPH (l,l-diphenyl-2-picrylhydrazyl) radical scavenging, superoxide anion radical scavenging and hydrogen peroxide scavenging. The scavenging effect on hydroxyl radical and DPPH radical, which may be comparable to Vitamin C, while the scavenging effect on superoxide anion radicals was not obvious.展开更多
Reactive oxygen species (ROS) scavengers, including ascorbate peroxidase, superoxide dismutase, catalase and peroxidase, are the most commonly used biomarkers in assessing an organisms' response to many biotic and ...Reactive oxygen species (ROS) scavengers, including ascorbate peroxidase, superoxide dismutase, catalase and peroxidase, are the most commonly used biomarkers in assessing an organisms' response to many biotic and abiotic stresses. In this study, we cloned an 866 bp GST(phi) gene in Lemna minor and investigated its characteristics, expression and enzymatic activities under 75 lamol/L cadmium concentrations in comparison with other ROS scavengers. GST(phi) gene expression patterns were similar to those of other scavengers of ROS. This suggests that GST(phi) might be involved in responding to heavy metal (cadmium) stress and that its expression level could be used as a bio-indicator in monitoring cadmium pollution.展开更多
The present research work was carried out to investigate the proximate composition and antioxidant capacities of newly invented varieties of dry peas. The proximate composition in terms of moisture (7.00-8.50%), ash...The present research work was carried out to investigate the proximate composition and antioxidant capacities of newly invented varieties of dry peas. The proximate composition in terms of moisture (7.00-8.50%), ash (3.85-4.97%), fiber (3.8-12.3%) and protein (17.3-18.8%) contents varied significantly with respect to various cultivars. Total phenolic contents (TPC), total flavonoids contents (TFC), percentage inhibition of peroxidation of linoleic acid system, reducing power and DPPH free radical scavenging capacity of different dry peas extracts were found in range of 0.651-0.684 g/100g of GAE, 0.021-0.041 g/100g of CE, 0.713-0.895, 40.051-84.608%, 18.097-24.591 mg/mL, respectively. The amount of TFC, and percent inhibition of per oxidation in linoleic system of different dry peas extracts varied significantly among various cultivars and solvents. From the results of present investigations it is reasonable to say that 80% methanolic extracts of dry peas have exhibited varying degree of antioxidant activity.展开更多
Functional properties of Talbina were used in ancient Arab for nutritional purpose. It was a meal made from barley flour and milk. The high antioxidant Talbina was formulated from whole flour of harley and oat, milk, ...Functional properties of Talbina were used in ancient Arab for nutritional purpose. It was a meal made from barley flour and milk. The high antioxidant Talbina was formulated from whole flour of harley and oat, milk, date palm syrup (debis) and date palm seeds. The chemical composition, organoleptic properties and antioxidant activity of high antioxidant Talbina were determined. Sensory evaluation of traditional and high antioxidant Talbina showed that the developed product Talbina was considered as good for overall acceptability of all panelists. Also, the formulated Talbina contains high values of antioxidants components and natural nutrients. The antioxidant activity of formulated Talbina containing barley or oat may be due to presence of phenolic compounds and proanthocyanidins in the barley and oat. Increasing the antioxidant activity of high antioxidant Talbina containing barley and oat may be due to the adding of dates palm seeds which contain very high values of phenolic compounds and other antioxidants components. Date palm seeds as well as barley and/or oat give high antioxidants components which protect cells from oxidative stress and help to reduce the risk of cancer and heart disease as well as natural anti-depressant. Moreover, increasing the antioxidant activity in the formulated Talbina may play a role for reducing power, radical scavenging activity and the lipid peroxidation inhibition. In conclusion, supplementation of traditional Talbina containing barley and/or oat with date palm syrup (debis) and date palm seeds can produce simple and healthy meal to provide a good source of daily dietary antioxidants and micronutrients.展开更多
With the increasing interest on natural products discovery, utilization of plant parts which are commonly disregarded is another breakthrough. This study sought to determine the secondary metabolites present, phenolic...With the increasing interest on natural products discovery, utilization of plant parts which are commonly disregarded is another breakthrough. This study sought to determine the secondary metabolites present, phenolic contents, radical scavenging activities and antibacterial properties of 10 selected ornamental flowers which were Adenium obesum, Allamanda cathartica, Bougainvillea glabra, Catharanthus roseus, Caesalpinia pulcherrima, Heliconia subulata, Ixora coccinea, Mussaenda philippica, Tecoma stans and Torenia fournieri, from Nueva Vizcaya, Philippines. The ethanolic crude extracts were subjected to thin layer chromatography (TLC) phytochemical screening. Total phenolics expressed as mg AAE/g sample were determined through Folin-Ciocalteu method. Radical scavenging activities were measured using DPPH assay. Antibacterial activities were assessed through TLC bioautography. To quantify bacterial susceptibility of C. pulcherrima, MIC and MBC were employed in the ethyl acetate sub-fraction. TLC showed different types of phenolics, alkaloids, essential oils and terpenes. T. fournieri showed the highest total phenolics with 155 mg AAE/g while H. subulatahad showed the lowest with 3.50 mg AAE/g. Measurement of IC59 showed that H. subulata had the highest antioxidant activity followed by T. fournieri with 303 ppm and 320 ppm, respectively. H. subulata having the least amount of total phenolics had greatest radical scavenging activity. This indicates that other than phenolics, other metabolites can pose great antioxidant activities. The antibacterial testing showed that M. philippica, 1. coccinea, 1-1. subulata, C. pulcherrima and A. cathartica were bioactive against Staphylococcus aureus and Escherichia coll. MIC and MBC of C. pulcherrima ethyl acetate sub-fraction is within the range of 2.5-10 mg/mL.展开更多
Cephalexin's traces within pharmaceutical effluents have toxic impact toward ecological and human health. Low-cost activated carbon derived from Trapa natans husk was oxidized with hydrogen peroxide and nitric acid, ...Cephalexin's traces within pharmaceutical effluents have toxic impact toward ecological and human health. Low-cost activated carbon derived from Trapa natans husk was oxidized with hydrogen peroxide and nitric acid, and tested for their ability to re- move cephalexin from aqueous solutions. Oxidization with H202 showed negative effect on the cephalexin sorption, whereas HNO3 oxidization improved the adsorption. The cephalexin adsorption isotherms on the native and HNO3 oxidized carbons correlated well with the Freundlich equation while their kinetics followed the pseudo-second order model. The removal of cephalexin by the native and HNO3 oxidized carbons was found to be most favored at low ionic strength and strong acidic conditions. Based on the thermal and FTIR analyses, the interaction mechanisms of the interaction between cephalexin and the carbons were proposed. Electrostatic attraction, hydrophobic interaction and chemical bonding with surface functional groups were demonstrated as primary mechanisms for cephalexin removal. The nitrogen functionalities on the carbon surface were considered to be an important factor affecting the adsorption process.展开更多
Predators induce plastic responses in multiple prey taxa, ranging from morphological to behavioral or physiological changes. In amphibians, tadpoles activate plastic responses to reduce predation risk by reducing thei...Predators induce plastic responses in multiple prey taxa, ranging from morphological to behavioral or physiological changes. In amphibians, tadpoles activate plastic responses to reduce predation risk by reducing their activity rate and altering their morphology, specifically tail depth and pigmentation. Furthermore, there is now evidence that tadpoles' defenses are modi- fied when predators combine with other stressful factors such as pollutants or competitors, but our knowledge on the physiologi- cal responses underlying these responses is still scarce. Here we study physiological responses in Pelobates cultripes tadpoles exposed to a natural predator (larvae of the aquatic beetle Dytiscus circumflexus), non-lethal concentrations of herbicide (gly- phosate, 0.5 mg/L and 1.0 mg/L) or both factors combined. We measured corticosterone levels, standard metabolic rate, oxidative damage (TBARS) and activity of antioxidant enzymes, and immune response (via leukocyte count). Tadpoles reduced their corti- costerone concentration by ca. 24% in the presence of predator cues, whereas corticosterone did not change in the presence of glyphosate. Two enzymes involved in antioxidant response also decreased in the presence of predators (14.7% and 13.2% respec- tively) but not to glyphosate. Herbicide, however, increased the number of neutrophils and reduced that of lymphocytes, and had an interaction effect with predator presence. Standard metabolic rate did not vary across treatments in our experiment. Thus we show a marked physiological response to the presence of predators but little evidence for interaction between predators and low levels of herbicide. Multiple assessment of the physiological state of animals is important to understand the basis and conse- quences ofphenotypic plasticity展开更多
文摘Objective The SOD, POD and APX enzyme activities of tetraploid lines and diploid control line of Chrysanthemum cinerariifolium in test-tube and field were determined in order to provide a reference for the selective breeding of high resistance good tetraploid varieties of C. cinerariifolium. Method The SOD, POD and APX activities of each sample were determined. Every material should have 3 replicates which been determined and calculated mean value to analyze. Result The various kinds of antioxidase activities in protective enzyme system of tetraploid lines were increased generally in comparison with that of diploid control line. And there is certain relativity between the samples in field and in test-tube of these lines. Conclusion The antioxidase activities of each line in test-tube could be considered as reference index to screen high resistance good tetraploid varieties of C. cinerariifolium.
文摘To study the antioxidant constituents from the stems of Dendrobium nobile, and to discuss theft structure-activity relationship. Compounds were isolated from a 60% ethanolic extract by various chromatographic techniques and were identified by spectral analysis. The antioxidant activities of compounds were evaluated by DPPH free radical scavenging assay. Five phenanthrenes and four lignans were obtained from the active fractions ofD. nobile. Their structures were identified as fimbriatone (1), confusarin (2), flavanthrinin (3), 2,5-dihydroxy-4,9-dimethoxyphenanthrene (4), 3,7-dihydroxy-2,4-dimethoxyphenanthrene (5), syringaresinol (6), pinoresinol (7), medioresinol (8) and lirioresinol-A (9), respectively. Compounds 2 and 6 exhibited more potent DPPH scavenging activities than vitamin C. All the above compounds were reported from this plant for the first time, and compounds 3, 4 and 9 were reported for the first time from the genus of Dendrobiurn. For all phenanthrenes and lignans, an electron-donating methoxyl group in the ortho position to the phenolic hydroxyl group exhibits enhanced antioxidant activities.
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China (No.20902056 and No.20973108), the Innovation Foundation of Shanghai University, and the Leading Academic Discipline Project of Shanghai Municipal Education Commission (No.J50101).
文摘The molecular structure and radical scavenging activity of three novel antioxidants from Lespedeza Virgata, lespedezavirgatol, lespedezavirgatal, and lespedezacoumestan, have been studied using density functional theory with the B3LYP and BhandHLYP methods. The optimized geometries of neutral, radical cation, radical and anion forms were obtained at the B3LYP/6-31G(d) level, in which it was found that all the most stable conformations contain intramolecular hydrogen bonds. The same results were obtained from the MP2 method. The homolytic O-H bond dissociation enthalpy and the adiabatic ionization potential of neutral and anion forms for the three new antioxidants and adiabatic electron affinity and H-atom affinity for hydroxyl radical, superoxide anion radical, and hydrogen peroxide radical were determined both in gas phase and in aqueous solution using IEF-PCM and CPCM model with UAHF or Bondi cavity. The antioxidant activities and reactive oxygen species scavenging mechanisms were then discussed, and the results obtained from different methods are consistent. Furthermore, the antioxidant activities are consistent with the experimental findings of the compounds under investigation.
基金Supported by the Commonweal Item of State Oceanic Administration of the People's Republic of China(Nos.201305016-2,201405038-2)
文摘Mackerel (Pneumatophorus japonicus) proteins were hydrolyzed by five proteases: trypsin, papain, neutrase, acid protease, and flavourzyme. The hydrolysate treated by neutrase exhibited the highest antioxidant activity. Response surface methodology (RSM) was employed to optimize the hydrolysis conditions in an effort to obtain a mackerel protein hydrolysate (MPH) with the highest DPPH radical scavenging activity. The MPH was fractioned using a series of ultrafiltration membranes and five fractions, namely, MPH-I (〉10 kDa), MPH-II (10-2.5 kDa), MPH-III (1-2.5 kDa), MPH-IV (0.4-1 kDa), and MPH-V (below 0.4 kDa), were obtained. DPPH radical scavenging activity, reducing power, hydroxyl radical scavenging activity, and the lipid peroxidation inhibition capability of these fractions were evaluated. The fractions in molecular weights 〈2.5 kDa (MPH-III, MPH-IV, and MPH-V), which occupied 93.4% of the total fractions, showed the strongest antioxidant activity; and the antioxidant activities of the three fractions are similar to each other. Using SP Sephadex C-25 and Sephadex G-25 columns, eight fractions were obtained from the MPH (〈2.5 kDa). The isolated peptide I (1 664 kDa) displayed the highest DPPH radical scavenging activity. Therefore, MPH is a potential source of antioxidant peptides.
基金Project(CZQ13002)supported by the Special Fund for Basic Scientific Research of Central Universities,China
文摘Heterogeneous Fenton-like process using fly ash as a catalyst was studied to degrade n-butyl xanthate form aqueous solution. The different reaction parameters on the degradation efficiency of the process were investigated. The fly ash/H2O2 catalyst possesses a high oxidation activity for n-butyl xanthate degradation in aqueous solution. It is found that both the dosage of catalyst and initial solution pH significantly affect the n-butyl xanthate conversion efficient. The results indicate that by using 1.176 mmol/L H2O2 and 1.0 g/L fly ash catalyst with mass fraction of 4.14% Fe(III) oxide at pH 3.0, almost 96.90% n-butyl xanthate conversion and over 96.66% COD removal can be achieved within 120 min with heterogeneous catalysis by fly ash. CS2 as an intermediate of n-butyl xanthate oxidation. Finally, it is demonstrated that the fly ash/H2O2 catalytic oxidation process can be an efficient method for the treatment of n-butyl xanthate containing wastewater.
文摘We evaluated the hydroxyl and alkyl-oxy radical scavenging activity of instant coffee using an electron spin resonance (ESR) spin-trapping method, which was based the spin-trapping reagent 5-(2,2-dimethy-l,3-propoxycyclophosphoryl)-5-methyl-l-pyrroline N-oxide (CYPMPO). In this method, very pure hydroxyl and alkyl-oxy radicals were generated by illuminating a phosphate buffer solution containing hydrogen peroxide and 2,2'-azobis (2-amidinopropane) dihydrochloride with a Hg-Xe arc lamp. The ESR adduct signal was sensitive and very stable. We concluded that instant coffee has high hydroxyl radical and alkyl-oxy radical scavenging activity.
基金Project(51906089)supported by the National Natural Science Foundation of ChinaProject(NELMS2018A18)supported by the National Engineering Laboratory for Mobile Source Emission Control Technology,China+1 种基金Project(XNYQ2021-002)supported by the Provincial Engineering Research Center for New Energy Vehicle Intelligent Control and Simulation Test Technology of Sichuan,ChinaProject(GY2020016)supported by the Zhenjiang City Key R&D Program,China。
文摘Fe-ZSM-5 catalysts modified by Cu and Ce by aqueous solution ion-exchange and incipient wetness impregnation methods were tested in the selective catalytic reduction of NO_(x) with NH_(3).A variety of characterization techniques(NH_(3)-SCO,BET,XRD,XPS,UV-Vis,NH_(3)-TPD,H_(2)-TPR)were used to explore the changes of the active sites,acid sites and pore structure of the catalyst.It was found that the dispersion of active Cu species and Fe species had great influences on the catalytic activity in the whole catalytic process.The Cu doping into the Fe-ZSM-5 catalyst produced new active species,isolated Cu ions and CuO particles,resulting in the improved low-temperature catalytic activity.However,the NH_(3) oxidation was enhanced,and part of the Fe^(3+)active sites and more Brønsted acidic sites in the catalyst were occupied by Cu species,which causes the decrease of the high-temperature activity.The recovery of hightemperature activity could be attributed to the recovery of active Cu species and Fe species promoted by Ce and the promotion of active species dispersion.The results provide theoretical support for adjusting the active window of Febased SCR catalyst by multi-metal doping.
基金supported by the High Technology Research and Development Program of China (No. 2006AA09Z438)the National Natural Science Foundation of China (No. 30871943).
文摘Fish skin collagen hydrolysates (FSCH) were prepared from walleye pollock (Theragra chalcogramrna) using a mixture of enzymes, namely trypsin and flavourzyme. The degree of hydrolysis of the skin collagen was 27.3%. FSCH was mainly composed of low-molecular-weight peptides and the relative proportion of 〈1000Da fraction was 70.6%. Free radical and oxygen species scavenging activities of FSCH were investigated in four model systems, including diphenylpicrylhy-drazyl radical (DPPH), superoxide anion radical, hydroxyl radical and hydrogen peroxide model, and compared with that of a native antioxidant, reduced glutathione (GSH). FSCH was also evaluated by water-absorbing and water-holding capacity. The results showed that FSCH was able to scavenge free radical and oxygen species significantly and to enhance water-absorbing and water-holding capacity remarkably. Therefore FSCH may have potential applications in the medicine and food industries.
基金This project was supported by Grant 31200884 from the National Natural Science Foundation of China Grant 2016D016, 2016-ZQN-92, and 2016-2-75 from the Natural Science Foundation of Fujian and Grant 3502Z20154048, 3502Z20144061, and 3502Z20154047 from the Natural Scien- ce Foundation of Xiamen.
文摘Background In type 2 diabetes mellitus (T2DM), high-density lipoprotein (HDL) impairs its anti-atherogenic properties and even develops to a pro-inflammatory and pro-atherogenic phenotype because of abnormal compositions and modifications. In this study, we ex- amined the effects and the related mechanisms of glycation of HDL on the proliferation and migration of vascular smooth muscle cells (VSMCs). Methods & Results Glycated HDL (G-HDL) was modified with D-glucose (25 mmol/L) in vitro. Diabetic HDL (D-HDL) was isolated from T2DM patients. Rat VSMCs were isolated from the thoracic aortas. Human VSMCs were obtained from ScienCell Research Laboratories. Alpha-actin was detected through immunofiuorescence. VSMC proliferation was assayed by Cell Count. VSMC migration was determined by transwell chamber and scratch-wound assay. Intracellular reactive oxygen species (ROS) was detected based on ROS-medi- ated 2',7'-dichlorofluorescein (DCFH-DA) fluorescence. Compared to native HDL (N-HDL), G-HDL remarkably promoted VSMC prolif- eration and migration in the dose and time-dependent manners. In addition, G-HDL enhanced ROS generation in VSMCs. However, the ROS scavenger, N-acetylcysteine, efficiently decreased ROS production and subsequently inhibited the proliferation of VSMCs induced by G-HDL. Similarly, D-HDL from T2DM patients also promoted ROS release and VSMC proliferation and migration. Conclusions HDL either glycated in vitro or isolated from T2DM patients triggered VSMC proliferation, migration, and oxidative stress. These results might partly interpret the higher morbidity of cardiovascular disease in T2DM patients.
基金supported by the National Basic Research Program of China (Grant No 2006CB101805)Undergraduate Innovative Experiment Program of China (Grant Number 091042328)
文摘The toxic mechanism of herbicide butachlor to induce extremely high lethality in marine flatfish flounder, Paralichthys Olivaceus, was analyzed by histopathological examination, antioxidant enzymes activities and ATP content assay. Histopathological examination of gill, liver and kidney of exposed fishes showed that gill was a target organ of butachlor. The butachlor seriously impaired the respiration of gills by a series of lesions such as edema, lifting and detachment of lamellar epithelium, breakdown of pillar cells, and blood congestion. The dysfunction of gill respiration caused suffocation to the exposed flounder with extremely high acute lethality. Antioxidant enzyme activity assay of the in vitro cultured flounder gill (FG) ceils exposed to butachlor indicated that butachlor markedly inhibited the antioxidant enzyme activities of Superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX). Furthermore, along with the decline of antioxidant enzyme activities, ATP content in the exposed FG cells decreased, too. This infers that the oxidative stress induced by butachlor can inhibit the production of cellular ATP. Similar decrease of ATP content was also observed in the exposed flounder gill tissues. Taken together, as in FG cells, butachlor possibly induced a short supply of ATP in pillar cells by inhibiting the antioxidant enzyme activities and then affecting the contractibility of the pillar cells, which in turn resulted in the blood congestion and suffocation of exposed flounder.
基金Supported by the Major Science and Technology Program for Water Pollution Contro and Treatment-Crucial Technology Research and Engineering Sample Subject on Municipa Wastewater Treatment Process Updated to Higher Drainage Standard(2008ZX07317-02)Wuhan Water Pollution Control and the Water Environment Administer Technology and Synthetic Sample Project in Cities and Towns(2008ZX07317)
文摘A pilot-scale modified carbon source division anaerobic anoxic oxic(AAO) process with pre-concentration of returned activated sludge(RAS) was proposed in this study for the enhanced biological nutrient removal(BNR) of municipal wastewater with limited carbon source. The influent carbon source was fed in step while a novel RAS pre-concentration tank was adopted to improve BNR efficiency, and the effects of an influent carbon source distribution ratio and a RAS pre-concentration ratio were investigated. The results show that the removal efficiency of TN is mainly influenced by the carbon source distribution ratio while the TP removal relies on the RAS pre-concentration ratio. The optimum carbon source distribution ratio and RAS pre-concentration ratio are 60% and 50%, respectively, with an inner recycling ratio of 100% under the optimum steady operation of pilot test, reaching an average effluent TN concentration of 9.8 mg·L-1with a removal efficiency of 63% and an average TP removal efficiency of 94%. The mechanism of nutrient removal is discussed and the kinetics is analyzed. The results reveal that the optimal carbon source distribution ratio provides sufficient denitrifying carbon source to each anoxic phase, reducing nitrate accumulation while the RAS pre-concentration ratio improves the condition of anaerobic zone to ensure the phosphorus release due to less nitrate in the returned sludge. Therefore, nitrifying bacteria, denitrifying bacteria and phosphorus accumulation organisms play an important role under the optimum condition, enhancing the performance of nutrient removal in this test.
文摘On the basis of study on the mechanism of action of sulfonylurea herbicides, nine sulfonylurea derivatives of iso-{xazolidinone} were designed and synthesized. The structures of these compounds were confirmed by means of IR, MS, NMR and elemental analysis. The results of preliminary active tests indicate that the compounds have some herbicidal activity. The structure-activity relationship was also studied.
文摘Polysaccharides of Tricholoma matsutake Sing. were extracted with boilingwater, followed by precipitating with ethanol. Two membranes of different molecular weight cut-off, namely, 30 kD and 10 kD were chosen with ultrafiltration. The antioxidant activity of the purification polysaccharides was evaluated by various antioxidant assay, including DPPH (l,l-diphenyl-2-picrylhydrazyl) radical scavenging, superoxide anion radical scavenging and hydrogen peroxide scavenging. The scavenging effect on hydroxyl radical and DPPH radical, which may be comparable to Vitamin C, while the scavenging effect on superoxide anion radicals was not obvious.
基金Supported by the National Natural Science Foundation of China(No.31370296)the Shandong Provincial Natural Science Foundation of China(Nos.Y2007D34,ZR2011CM044)the Key Technologies R&D Program of Shandong Province of China(No.2010GNC10937)
文摘Reactive oxygen species (ROS) scavengers, including ascorbate peroxidase, superoxide dismutase, catalase and peroxidase, are the most commonly used biomarkers in assessing an organisms' response to many biotic and abiotic stresses. In this study, we cloned an 866 bp GST(phi) gene in Lemna minor and investigated its characteristics, expression and enzymatic activities under 75 lamol/L cadmium concentrations in comparison with other ROS scavengers. GST(phi) gene expression patterns were similar to those of other scavengers of ROS. This suggests that GST(phi) might be involved in responding to heavy metal (cadmium) stress and that its expression level could be used as a bio-indicator in monitoring cadmium pollution.
文摘The present research work was carried out to investigate the proximate composition and antioxidant capacities of newly invented varieties of dry peas. The proximate composition in terms of moisture (7.00-8.50%), ash (3.85-4.97%), fiber (3.8-12.3%) and protein (17.3-18.8%) contents varied significantly with respect to various cultivars. Total phenolic contents (TPC), total flavonoids contents (TFC), percentage inhibition of peroxidation of linoleic acid system, reducing power and DPPH free radical scavenging capacity of different dry peas extracts were found in range of 0.651-0.684 g/100g of GAE, 0.021-0.041 g/100g of CE, 0.713-0.895, 40.051-84.608%, 18.097-24.591 mg/mL, respectively. The amount of TFC, and percent inhibition of per oxidation in linoleic system of different dry peas extracts varied significantly among various cultivars and solvents. From the results of present investigations it is reasonable to say that 80% methanolic extracts of dry peas have exhibited varying degree of antioxidant activity.
文摘Functional properties of Talbina were used in ancient Arab for nutritional purpose. It was a meal made from barley flour and milk. The high antioxidant Talbina was formulated from whole flour of harley and oat, milk, date palm syrup (debis) and date palm seeds. The chemical composition, organoleptic properties and antioxidant activity of high antioxidant Talbina were determined. Sensory evaluation of traditional and high antioxidant Talbina showed that the developed product Talbina was considered as good for overall acceptability of all panelists. Also, the formulated Talbina contains high values of antioxidants components and natural nutrients. The antioxidant activity of formulated Talbina containing barley or oat may be due to presence of phenolic compounds and proanthocyanidins in the barley and oat. Increasing the antioxidant activity of high antioxidant Talbina containing barley and oat may be due to the adding of dates palm seeds which contain very high values of phenolic compounds and other antioxidants components. Date palm seeds as well as barley and/or oat give high antioxidants components which protect cells from oxidative stress and help to reduce the risk of cancer and heart disease as well as natural anti-depressant. Moreover, increasing the antioxidant activity in the formulated Talbina may play a role for reducing power, radical scavenging activity and the lipid peroxidation inhibition. In conclusion, supplementation of traditional Talbina containing barley and/or oat with date palm syrup (debis) and date palm seeds can produce simple and healthy meal to provide a good source of daily dietary antioxidants and micronutrients.
文摘With the increasing interest on natural products discovery, utilization of plant parts which are commonly disregarded is another breakthrough. This study sought to determine the secondary metabolites present, phenolic contents, radical scavenging activities and antibacterial properties of 10 selected ornamental flowers which were Adenium obesum, Allamanda cathartica, Bougainvillea glabra, Catharanthus roseus, Caesalpinia pulcherrima, Heliconia subulata, Ixora coccinea, Mussaenda philippica, Tecoma stans and Torenia fournieri, from Nueva Vizcaya, Philippines. The ethanolic crude extracts were subjected to thin layer chromatography (TLC) phytochemical screening. Total phenolics expressed as mg AAE/g sample were determined through Folin-Ciocalteu method. Radical scavenging activities were measured using DPPH assay. Antibacterial activities were assessed through TLC bioautography. To quantify bacterial susceptibility of C. pulcherrima, MIC and MBC were employed in the ethyl acetate sub-fraction. TLC showed different types of phenolics, alkaloids, essential oils and terpenes. T. fournieri showed the highest total phenolics with 155 mg AAE/g while H. subulatahad showed the lowest with 3.50 mg AAE/g. Measurement of IC59 showed that H. subulata had the highest antioxidant activity followed by T. fournieri with 303 ppm and 320 ppm, respectively. H. subulata having the least amount of total phenolics had greatest radical scavenging activity. This indicates that other than phenolics, other metabolites can pose great antioxidant activities. The antibacterial testing showed that M. philippica, 1. coccinea, 1-1. subulata, C. pulcherrima and A. cathartica were bioactive against Staphylococcus aureus and Escherichia coll. MIC and MBC of C. pulcherrima ethyl acetate sub-fraction is within the range of 2.5-10 mg/mL.
基金supported by the National Key Technology R&D Program for the 11th Five-year Plan (2006BAC10B03)the National Water Special Project (2009ZX07210-009-04)+1 种基金the Scientific Technology Research and Development Program of Shandong,China (2010GZX20605)Graduate Independent Innovation Foundation of Shandong University(2009JQ009)
文摘Cephalexin's traces within pharmaceutical effluents have toxic impact toward ecological and human health. Low-cost activated carbon derived from Trapa natans husk was oxidized with hydrogen peroxide and nitric acid, and tested for their ability to re- move cephalexin from aqueous solutions. Oxidization with H202 showed negative effect on the cephalexin sorption, whereas HNO3 oxidization improved the adsorption. The cephalexin adsorption isotherms on the native and HNO3 oxidized carbons correlated well with the Freundlich equation while their kinetics followed the pseudo-second order model. The removal of cephalexin by the native and HNO3 oxidized carbons was found to be most favored at low ionic strength and strong acidic conditions. Based on the thermal and FTIR analyses, the interaction mechanisms of the interaction between cephalexin and the carbons were proposed. Electrostatic attraction, hydrophobic interaction and chemical bonding with surface functional groups were demonstrated as primary mechanisms for cephalexin removal. The nitrogen functionalities on the carbon surface were considered to be an important factor affecting the adsorption process.
文摘Predators induce plastic responses in multiple prey taxa, ranging from morphological to behavioral or physiological changes. In amphibians, tadpoles activate plastic responses to reduce predation risk by reducing their activity rate and altering their morphology, specifically tail depth and pigmentation. Furthermore, there is now evidence that tadpoles' defenses are modi- fied when predators combine with other stressful factors such as pollutants or competitors, but our knowledge on the physiologi- cal responses underlying these responses is still scarce. Here we study physiological responses in Pelobates cultripes tadpoles exposed to a natural predator (larvae of the aquatic beetle Dytiscus circumflexus), non-lethal concentrations of herbicide (gly- phosate, 0.5 mg/L and 1.0 mg/L) or both factors combined. We measured corticosterone levels, standard metabolic rate, oxidative damage (TBARS) and activity of antioxidant enzymes, and immune response (via leukocyte count). Tadpoles reduced their corti- costerone concentration by ca. 24% in the presence of predator cues, whereas corticosterone did not change in the presence of glyphosate. Two enzymes involved in antioxidant response also decreased in the presence of predators (14.7% and 13.2% respec- tively) but not to glyphosate. Herbicide, however, increased the number of neutrophils and reduced that of lymphocytes, and had an interaction effect with predator presence. Standard metabolic rate did not vary across treatments in our experiment. Thus we show a marked physiological response to the presence of predators but little evidence for interaction between predators and low levels of herbicide. Multiple assessment of the physiological state of animals is important to understand the basis and conse- quences ofphenotypic plasticity