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4-溴苯酚的酶催化聚合及其抗自由基性能 被引量:3
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作者 张磊 张艳丽 +2 位作者 郑轲 高亚会 崔元臣 《化学研究》 CAS 2014年第6期622-626,631,共6页
在有机溶剂和缓冲溶液的混合体系中对4-溴苯酚的酶催化聚合反应进行了研究;利用红外光谱分析了产物的分子结构.结果表明,有机溶剂与缓冲溶液配比对反应产率和产物分子量影响较大.以乙醇为有机溶剂,当其与磷酸盐缓冲溶液(pH=7)体积比为1... 在有机溶剂和缓冲溶液的混合体系中对4-溴苯酚的酶催化聚合反应进行了研究;利用红外光谱分析了产物的分子结构.结果表明,有机溶剂与缓冲溶液配比对反应产率和产物分子量影响较大.以乙醇为有机溶剂,当其与磷酸盐缓冲溶液(pH=7)体积比为1∶3时,反应产率较高,而聚合产物的分子量随反应体系中乙醇含量的增加呈上升趋势.与此同时,4-溴苯酚聚合物分子链含有苯-苯连接和苯-氧连接两种结构;4-溴苯酚聚合物的热分解温度在250℃左右,具有较好的热稳定性;且其对1,1-二苯基-2-三硝基苯肼(DPPH)自由基和2,2′-联氮双(3-乙基苯并噻唑啉-6-磺酸)二铵盐(ABTS)阳离子自由基均表现出明显的抑制作用. 展开更多
关键词 4-溴苯酚 酶催化 聚合 抗自由基性能
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3种分光光度法对天然抗氧化物质抗自由基性能的分析检测
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作者 高兰玲 《科技资讯》 2015年第12期247-247,共1页
该文在分析检测天然抗氧化物质抗自由基的性能,借助于3种分光光度法来比较研究。在3种分光度法对自由基进行分析检测,包括对抗氧化剂的抗自由基性能进行检测的方法上,可适应相关研究工作或者常规实验室检测自由基的需要。
关键词 分光光度法 天然氧化物质 抗自由基性能
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甲硫氨酸席夫碱铜、锌、钴配合物合成及抗O^._2性能 被引量:9
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作者 陈德余 张义建 张平 《应用化学》 CAS CSCD 北大核心 2000年第6期607-610,共4页
合成了邻香草醛甲硫氨酸席夫碱及其铜、锌、钴等配合物 ,通过元素分析、摩尔电导、红外光谱、电子光谱、热分析及电子顺磁共振等手段对它们进行了表征 ,并用 EPR法探讨了它们对O· -2 的清除作用 .结果表明 ,配体与配合物均具有抗 O... 合成了邻香草醛甲硫氨酸席夫碱及其铜、锌、钴等配合物 ,通过元素分析、摩尔电导、红外光谱、电子光谱、热分析及电子顺磁共振等手段对它们进行了表征 ,并用 EPR法探讨了它们对O· -2 的清除作用 .结果表明 ,配体与配合物均具有抗 O· -2 性能 ,配合物清除能力比配体强 。 展开更多
关键词 甲硫氨酸席夫碱 配合物 自由性能
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一种用于护肤品中的新原料
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《日用化学品科学》 CAS 2003年第4期43-43,共1页
美国科学家Dr.JackMasguilier研究发现,在自然界的松树皮、葡萄籽,柿子、桃及麦类植物中,存在一种抗氧化和抗自由基性能极强的营养物质——前花青素。该物质是一种很强的抗氧化剂,相比于维生素类,其抗氧化能力要高20倍~30倍,同时。
关键词 护肤品 原料 氧化 抗自由基性能 氧化剂
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Purification and characterization of novel antioxidant peptides of different molecular weights from mackerel Pneumatophorus japonicus protein hydrolysate 被引量:4
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作者 王雪芹 邢荣娥 +4 位作者 刘松 于华华 李克成 陈作元 李鹏程 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2015年第1期159-168,共10页
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
关键词 mackerel protein antioxidant activity fraction of hydrolysate ULTRAFILTRATION PURIFICATION
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Isolation and Characterization of Fucoidans from Five Brown Algae and Evaluation of Their Antioxidant Activity 被引量:3
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作者 QU Guiyan LIU Xu +2 位作者 WANG Dongfeng YUAN Yi HAN Lijun 《Journal of Ocean University of China》 SCIE CAS 2014年第5期851-856,共6页
In this study, we evaluated the chemical property and antioxidant activity of fucoidans isolated from brown algae, Laminaria japonica(LJF), Lessonia nigrescens(LNF), Lessonia trabeculata(LTF), Ascophyllum mackaii(AMF)... In this study, we evaluated the chemical property and antioxidant activity of fucoidans isolated from brown algae, Laminaria japonica(LJF), Lessonia nigrescens(LNF), Lessonia trabeculata(LTF), Ascophyllum mackaii(AMF), and Ecklonia maxima(EMF). LJF was less in sulfate content(14.16%) and more in galactose and mannose content(1.08 and 0.68) than the documented early. EMF contained 20%–30% of sulfate and fucose, 0.97 in molar ratio which was lower than that of sulfate to other four fucoidans(1.21–1.41). AMF(162 kDa) and EMF(150 kDa) were the first two largest in molecular weight, which were followed by LJP(126 kDa), LNF(113 kDa) and LTF(105 kDa). The fucoidans isolated these algae showed a wide range of antioxidant activity in vitro. It was found that the reducing power of the isolated fucoidans was positively correlated with their sulfate content and molecular weight. In addition, LNF and LTF at low concentrations exhibited high superoxide and hydroxyl radical scavenging activity. This demonstrated that low molecular weight fucoidans may perform a high antioxidant activity. 展开更多
关键词 fucoidans composition antioxidant property Laminaria japonica Lessonia nigrescens Lessonia trabeculata Ascophyllum mackaii Ecklonia maxima
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Antioxidant properties of wheat germ protein hydrolysates evaluated in vitro 被引量:6
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作者 程云辉 王璋 许时婴 《Journal of Central South University of Technology》 EI 2006年第2期160-165,共6页
Wheat germ protein hydrolysates were prepared by protease hydrolysis, ultrafiltration and dynamical adsorption of resin. The total amount of amino acids in 100 g wheat germ protein hydrolysates is 93.95 g. Wheat germ ... Wheat germ protein hydrolysates were prepared by protease hydrolysis, ultrafiltration and dynamical adsorption of resin. The total amount of amino acids in 100 g wheat germ protein hydrolysates is 93.95 g. Wheat germ protein hydrolysates are primarily composed of 4 fractions: 17.78% in the relative molecular mass range of 115631512, 17.50% in 1512842, 27.38% in 842372 and 30.65% in 37276, respectively. The antioxidant properties of wheat germ protein hydrolysates were evaluated by using different antioxidant tests in vitro. 1.20 g/L wheat germ protein hydrolysates exhibit 78.75% inhibition of peroxidation in linolei acid system; and 1.6g/L wheat germ protein hydrolysates show 81.11% scavenging effect on the 1,1-diphenyl-2-picrylhrazyl radical. The reducing power of 2.50 g/L wheat germ protein hydrolysates is 0.84. Furthermore, the scavenging activity of 0.60 g/L wheat germ protein hydrolysates against superoxide radical is 75.40%; 0.50 g/L wheat germ protein hydrolysates exhibit 63.35% chelating effect on ferrous ion. These antioxidant activities of wheat germ protein hydrolsates increase with the increase of its concentration. Experimental results suggest that wheat germ protein hydrolysate is a suitable natural antioxidant rich in nutrition and nontoxic. 展开更多
关键词 wheat germ protein hydrolysate wheat germ ANTIOXIDANT free radical
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Evaluation of Free Radicals and Antioxidant Properties of Virus Infected Food Crops in Azerbaijan
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作者 Irada Huseynova Jalal Aliyev 《Journal of Life Sciences》 2012年第12期1307-1316,共10页
Abstract: Viral diseases are an important limiting factor in many crop production systems in Azerbaijan. Symptomatic plants in main crop-producing areas were tested by ELISA (enzyme-linked immunosorbent assay) usin... Abstract: Viral diseases are an important limiting factor in many crop production systems in Azerbaijan. Symptomatic plants in main crop-producing areas were tested by ELISA (enzyme-linked immunosorbent assay) using specific monoclonal and polyclonal antibodies. Then RCA (rolling circle amplification) of circular DNA and PCR using different specific primer pairs have indicated that the tested symptomatic plant samples were completely infected by the following viruses: Luteovirus [BLRV (Bean leaf roll virus)], Potyviruses [BCMV (Bean common mosaic virus), BYMV (Bean yellow mosaic virus)], Bromovirus [(AMV) Alfa-alfa mosaic virus], Geminiviruses [CpCDV ( Cickpea chlorotic dwarf virus) and TYLCV (Tomato yellow leaf curl virus)] and Nanoviruses [two different FBNYV (Faba bean necrotic yellow virus) and FBNSV (Faba bean necrotic stunt virus)]. At the same time generation sites of superoxide and hydrogen peroxide radicals and activity of antioxidant enzymes were studied in the naturally infected plants. 展开更多
关键词 Food crops virus-like symptoms viral diseases molecular methods reactive oxygen species antioxidant enzymes.
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Antioxidative activity of protein hydrolysates from anchovy
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作者 DING Li-jun LAI Xue-ling LIU Xiao-qing 《Journal of Chemistry and Chemical Engineering》 2008年第6期56-59,65,共5页
Alcalase hydrolyzed protein from Anchovy under controlled condition, and the hydrolysates were rich in active peptides. The peptide content was determined by TCA-biuret method, and amino acid was determined by Ninhydr... Alcalase hydrolyzed protein from Anchovy under controlled condition, and the hydrolysates were rich in active peptides. The peptide content was determined by TCA-biuret method, and amino acid was determined by Ninhydrin. The antioxidative activity of the hydrolysates was investigated by measuring the reducing ability, the inhibition of lipoxygenase activity, and antioxidative ability in linoleic acid oxidation system. The hydrolysates exhibited high antioxidative activity. In addition, the hydrolysates scavenged 58.38% on hydroxyl radical and 46.88% on superoxide radical. 展开更多
关键词 protein hydrolysatey PEPTIDES antioxidative activity free radicals ANCHOVY
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Determined of antioxidant activity and preventing DNA damage effect of peanut polypeptides by chemiluminescence method
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作者 LIU Li-na LU Jing +1 位作者 HE Dong-ping ZHANG Sheng-hua 《Journal of Life Sciences》 2009年第9期43-48,共6页
To estimate the antioxidant activities of Peanut polypeptides (PPs) by using a chemiluminescence (CL) method in vitro. The scavenging ability of PPs on superoxide anion, hydroxide radical, and hydrogen peroxide wa... To estimate the antioxidant activities of Peanut polypeptides (PPs) by using a chemiluminescence (CL) method in vitro. The scavenging ability of PPs on superoxide anion, hydroxide radical, and hydrogen peroxide was determined by the Pyrogallol-Luminol system, the CuSO4-Phen-Vc-H2O2 system, and the luminol-H2O2 system, respectively. DNA damage preventing the effect of PPs was determined by the CuSO4-Phen-Vc-H2O2-DNA CL system. The results shows that PPs had good effect on the scavenging ability of superoxide anion (IC50=9.68±0.12 mg/ml). PPs could scavenge hydroxide radical effectively (the IC50 value was 46.06±0.08 μg/ml). PPs had a good scavenging ability on hydrogen peroxide, which had a relatively low IC50 value (0.17±0.07 mg/ml). PPs (the IC50 value was0.72±0.11 mg/ml) were powerful on the DNA damage preventing effect. PPs possesses a good scavenging potency on ROS in different systems, but different results exist in different systems. 展开更多
关键词 peanut polypeptides CHEMILUMINESCENCE antioxidant activity in vitro DNA damage
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Analysis on the Oxidation Resistance of Jujube Saponin
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作者 Xiangqian ZHANG Xiao-long HE Jinbo ZHAO 《International Journal of Technology Management》 2015年第9期90-92,共3页
In this paper, saponins were extracted from Northern Shaanxi' s big jujubes using organic solvent method and also the oxidation resistance of the extractives was analyzed. In the experiment, the crude extractives of ... In this paper, saponins were extracted from Northern Shaanxi' s big jujubes using organic solvent method and also the oxidation resistance of the extractives was analyzed. In the experiment, the crude extractives of the saponins from jujubes were obtained using ethyl alcohol soaking method and Soxhlet extraction method and also qualitatively tested using 3 color reactions, and the test result was positive; the oxidation resistance of jujube saponins was analyzed through DPPH, hydroxyl radical scavenging experiment and reducibility measurement, and the results showed that the capability of jujube saponins in DPPH free radical scavenging was enhanced along with the improvement of the to- be-test material concentration, so saponins played a significant role on hydroxyl radical scavenging and possessed certain reducibility. Northern Shaanxi' s big jujubes are rich in saponins and possess excellent antioxidant ability that will be enhanced along with the increase of saponins content. Thus, a basis is provided for the effective extension of the jujube industry chain. 展开更多
关键词 Jujubes SAPONINS Oxidation Resistance
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Biochemical Mechanisms of Therapeutic and Prophylactic Effects of Bioflavonoids
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作者 Olga Makarenko Anatoly Levitsky 《Journal of Pharmacy and Pharmacology》 2016年第8期451-456,共6页
In the present study to investigate the biochemical mechanisms of therapeutic and prophylactic action of bioflavonoids, carried out a comparative evaluation of antioxidant and antiproteinase properties of certain biof... In the present study to investigate the biochemical mechanisms of therapeutic and prophylactic action of bioflavonoids, carried out a comparative evaluation of antioxidant and antiproteinase properties of certain bioflavonoids standards in vitro. Therapeutic and prophylactic efficacy of individual bioflavonoids as well as herbal medicines with bioflavonoids, was examined at an experimental pathology (toxic hepatitis, dental caries, periodontitis, stomatitis, dysbiosis, diabetes Types 1 and 2, gastric ulcer, osteopenia) in Wistar line rats. Condition of organs and tissues was assessed by biochemical markers of inflammation, antioxidant and antimicrobial defense systems of animals. Research has shown the ability ofbioflavonoids in varying degrees inhibit the formation of superoxide anion radicals and malondialdehyde, recover free radicals, bind ions of Fe2+, inhibiting the activity of proteases, such as leukocyte elastase. Established partially competitive type of trypsin and elastase activity inhibition by bioflavonoids. Was revealed a positive effect of bioflavonoids in experimental pathology on animals. Therapeutic and prophylactic effects of bioflavonoids, in our opinion, are realized through a strong antioxidant and antiprotease properties of these compounds. 展开更多
关键词 BIOFLAVONOIDS antioxidant and antiprotease properties in vitro experimental therapy.
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