查询词典 free radical

The antioxidetive activity of Boletus edulis Bull polysaccharide was studied and compared with Vc by using the superoxide anion free radical system,hydroxyl radical system in this paper.

李志洲，美味牛肝菌多糖的抗氧化性采用超氧阴离子自由基体系、羟基自由基体系，研究了美味牛肝菌多糖的抗氧化活性，并与Vc进行了比较。

Both of them showed no toxic effect on mice at the testing dose of 10 mg/kg. The 2,2-diphenyl-1-picrylhydrazyl free radical scavenging test showed that both of the formicary extracts were potent radical scavengers and their scavenging activities were dose-dependent. Furthermore, at higher concentrations (5～10 mg/ml) both of them exhibited significantly higher DPPH scavenging activity than butylated hydroxytoluene.

二苯基三硝基肼(1，1-diphenyl-2-picrylhydrazyl ，DPPH)自由基的清除能力的检测表明：两种蚂蚁窝甲醇提取物都具有显著的自由基清除能力，并呈现出剂量依赖性，而且，在高浓度时(5～10 mg·mL-1)，它们的自由基清除能力甚至显著地高于二丁基羟基甲苯(butylated hydroxyl toluene，BHT)。

ResultsThe results showed that two extracts of Galla Chinensis had strong scavenging effect on DPPH free radical. The IC50 of scavenging DPPH radical of the water extract and ethanol extract from Galla Chinensis were 0.414 7 mg/L and 0.858 6 mg/L respectively.

结果五倍子两种提取物具有良好的清除DPPH自由基的作用，在实验条件下，五倍子水提取物清除DPPH自由基的IC50为0.414 7 mg/L，五倍子醇提取物清除DPPH自由基的IC50为0.858 6 mg/L。

In one embodiment, the invention is a system for initiating free radical polymerization comprising: a in one part, one or more amido-borate compounds containing one or more anionic amido-borate moieties comprising an organoborate wherein the boron atom is bonded to a nitrogen atom of ammonia or an organic compound containing one or more nitrogen atoms, such as a hydrocarbyl amine, a hydrocarbyl polyamine, or an aromatic heterocycle containing one or more nitrogen atoms and optionally containing one or more heteroatoms or heteroatom containing functional moieties, and one or more cationic counter ions and b in a second part, a liberating compound which reacts with the nitrogen atom bound to the boron atom upon contact with the amido-borate to form an organoborane radical.

在一个实施方案中，本发明是引发自由基聚合的体系，包括：a在一个部分中，一种或多种含有一个或多个包含有机硼酸根的阴离子酰氨基-硼酸盐部分和一个或多个阳离子抗衡离子的酰氨基-硼酸盐化合物，其中的硼原子键合到氨的氮原子或含一个或多个氮原子的有机化合物，例如烃基胺、烃基聚胺或含一个或多个氮原子和任选含一个或多个杂原子或含杂原子的官能部分的芳族杂环的氮原子上，和b在第二部分中，在与酰氨基-硼酸盐接触时与键合到硼原子上的氮原子反应形成有机硼烷基团的释放化合物。

The results show that the formation of stable radical AH-R*between the antioxidant and the carbon-centred free radical R*from fat may be a main mechanism of the antioxidation to retard lipid rancid, and dihydrotanshinone I can also act as an antioxidant by donating a hydrogenatom to R*, becoming themselves an unreactive radical A*.

结果表明，抗氧化剂与油脂中碳中心自由基复合成稳定自由基，可能是丹参醌抑制或阻止油脂氧化酸败的主要途径，双氢丹参醌Ⅰ也可借助释放活泼H（本身转化成稳定自由基A*）有效清除R*。

The results show that the formation of stable radical AH-R* between the antioxidant and the carbon-centred free radical R* from fat may be a main mechanism of the antioxidation to retard lipid rancid, and dihydrotanshinone Ⅰ can also act as an antioxidant by donating a hydrogenatom to R*, becoming themselves an unreactive radical A*.

结果表明，抗氧化剂与油脂中碳中心自由基复合成稳定自由基，可能是丹参醌抑制或阻止油脂氧化酸败的主要途径，双氢丹参醌Ⅰ也可借助释放活泼H（本身转化成稳定自由基A*）有效清除R*。

The free radical scavenging properties of six Aloe species are to be investigated in some modified chemical system. The antioxidant was purified by silica column and thin layer chromatography and analyzed by HPLC. A fraction was purified from A. brevifolia Mill showed the most effective scavenging activities on 〓 and ·OH (66. 01% and 38. 98% respectively). With the analysis of IR spectrum, UV spectrum and mass spectrum, the structure of FA was identifed as 8-C-D-glucopyranosyl-2- [2-hydroxy] propyl-5-methyl-7-hydroxychromone. Its scavenging activity on free radicals is higher than that of aloe-emodin. Its antioxidant activity may be due to the phenoxyl on glucosyl chromone which can be react with free radicals and form relatively stable free radicals.

本研究利用分别产生超氧阴离子自由基和羟自由基的化学模型体系研究比较了不同品种芦荟提取物的清除活性氧自由基的抗氧化作用，进一步利用硅胶柱结合薄层层析法和反相高压液相色谱法，从短叶芦荟叶子中首次分离了具有较强自由基清除能力（超氧阴离子自由基和羟自由基清除率分别为66.01％和38.98％）的成分FA，利用红外光谱、紫外光谱和质谱等仪器分析结果推断出该活性成分的分子结构为8-C-吡喃葡萄糖-2-[2-羟基]-丙基-5-甲基-7-羟基对氧萘酮，它的自由基清除能力高于芦荟大黄素，是一种天然抗氧化剂。

It could not only eliminate free radical but also restrain the production of free radical.

不仅具有增强清除体内自由基的作用，还有抑制自由基产生的作用。

The method can be used to study free radical intermediate and non-free-radical intermediate, to study fast reaction and to fol...

该法既能研究自由基中间体，也能研究非自由基中间体，便于研究快反应和跟踪动态过程。

The deficiency of V〓 and the excessive UFA in feed resulted in the enhance of synthesizing and the reduce of clearing for free radical. So the free radical saved up in chicken. The content of ROS, MDA and NO and the activity of XOD increased.

饲料中V〓的缺乏和UFA的过量，使自由基的生成增多和清除减少，自由基在体内蓄积，表现为活性氧含量、MDA含量、NO含量的增加和XOD活性的增强。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。