查询词典 scavenging

The more the number of hydroxyl substitution in phenyl ring, the better the ability of scavenging DPPH free radical. That is, trihydroxy is better than dihydroxy, and dihydroxy is better than monohydroxy. Moreover, when the polyhydroxy exists in phenyl ring and it is ortho-position or para-position, the ability of scavenging DPPH free radical is better too.

当苯甲醯基的苯环上羟基取代数量越多，其清除DPPH自由基的能力越好，三羟基效果优於双羟基、单羟基，双羟基效果优於单羟基；而苯甲醯基苯环上若为多羟基且羟基的位置为邻位或对位的关系时，其在清除DPPH自由基的能力较佳。

The aim of this study was to examine the possible antioxidant and antiproliferative activities of the ethanol and water extracts of four Hydrocotyle species from Taiwan. ABTS radical monocation scavenging, FRAP method, DPPH radical scavenging, reducing power method, total polyphenol content, total The results showed that the water extracts of all the samples had higher antioxidant and antiproliferative activities than the ethanol extracts.

本实验针对台湾产四种天胡荽属植物之水萃取物及乙醇萃取物进行抗氧化及抗增生活性研究，分析方法包括ABTS自由基的清除、FRAP方法、DPPH自由基的清除、还原力、总多酚类含量、总类黄酮类含量、总黄酮醇类含量以及癌细胞增生之抑制，结果显示所有样品的水萃取物之抗氧化及抗增生活性皆大於乙醇萃取物，但在抗氧化活性方面，所有受测样品活性皆小於正对照组。

Then, the branch had better scavenging ABTS radical and hydroxyl radical scavenging activity than the other parts of Morus alba.

其次，在抗氧化活性上，桑枝有较佳之总抗氧化活性；桑叶则具较佳之DPPH 自由基清除能力及还原能力。

Based on relative literatures,this part has included five resesearch aspects as below.1 Fifteen compounds were isolated and purified by extraction,column chromatography,and their structures were determined on the basis of spectral analysis: acteoside(Ⅰ-1),isoacteoside(Ⅰ-2),crenatoside(Ⅰ-3),cistanoside F(Ⅰ-4),sinapoyl-4-O-β-D-glucoside(Ⅰ-5),adenosine(Ⅰ-6),β-siterol(Ⅰ-7),oleanic acid(Ⅰ-8), succinic acid(Ⅰ-9),caffeic acid(Ⅰ-10),protocatechuic aldehyde(Ⅰ-11),p-hydro xybenzyl alcohol(Ⅰ-12),β-daucosterol(Ⅰ-13),D-galacitol(Ⅰ-14),D-mannitol(Ⅰ-15).Ⅰ-4～15 were obtained from this plant for the first time,andⅠ-6,7,9,and 13 were isolated from Orobanche genus for the first time.2 The scavenging test of DPPH showed that most compounds have comparative antioxidant activity as L-ascorbic acid and part of them show better activity such as the O.coerulescens extract and phenylethanoid glycosides.Acteoside showed potent free radical scavenging effects with a median inhibition concentration of 25.6μg/ml.3 The anti-HBV activities of acteoside,isoacteoside and crenatoside were measured,and all of them showed suppressive activity on the expression of HBsAg and HBeAg in the HepG2.2.15 cell line.

本论文在文献调研基础上对紫花列当化学成分及生物活性进行了研究，并从免疫抗病毒角度探讨紫花列当中特征性成分类叶升麻苷的肝保护作用及其机制。1采用大孔树脂、硅胶和Sephadex LH-20等色谱技术对紫花列当进行系统的植物化学研究，从中分离得到19个化合物，利用UV和NMR等波谱手段及理化性质鉴定了其中的15个化合物，分别为类叶升麻苷(Ⅰ-1)、异类叶升麻苷(Ⅰ-2)、crenatoside(Ⅰ-3)、cistanoside F(Ⅰ-4)、sinapoyl-4-O-β-D-glucoside(Ⅰ-5)、腺苷(Ⅰ-6)、β-谷甾醇(Ⅰ-7)、齐墩果酸(Ⅰ-8)、琥珀酸(Ⅰ-9)、咖啡酸(Ⅰ-10)、原儿茶醛(Ⅰ-11)、对羟甲基苯甲酸(Ⅰ-12)、β-胡萝卜苷(Ⅰ-13)、D-半乳糖醇(Ⅰ-14)和甘露醇(Ⅰ-15除化合物Ⅰ-1、Ⅰ-2和Ⅰ-3外，其余化合物均为首次从该植物中分离得到。2)通过大孔树脂富集该药材有效部位苯乙醇总苷，并采用HPLC测得其所含特征性成分类叶升麻苷的含量可达80%以上。3DPPH自由基清除试验显示紫花列当提取物及其所含的苯乙醇苷类化合物均具有较好的抗氧化能力，其清除DPPH自由基能力接近于抗坏血酸。4采用卡介苗整体致敏、脂多糖离体攻击构建大鼠原代肝细胞免疫性损伤模型，在体外观察类叶升麻苷的保肝作用。

The scavenging effects of different solvent extracts on hydroxyl radicals produced by the system were compared by phenanthroline oxidation method, and change conditions of scavenging rate of hydroxyl radicals with the prolonging of time were studied.

方法］采用超声波提取法，分别以蒸馏水、50%乙醇和95%乙醇为溶剂，在40℃条件下提取30 min，获得了薄荷的不同溶剂提取物，并以邻二氮菲氧化法比较了不同溶剂提取物时体系产生的羟基自由基的清除作用，并研究随时间延长羟基自由基清除速率的变化情况。

The results of the ability of anti-oxidation scavenging DPPH free radical shows that polyhydroxy substituted N-benzoylserotonin derivatives (compound 1-10) have the generally better ability of anti-oxidation than control group, in which the IC50 of compound 1-10 ranges 8.75 to 18.02 μg/ml and the IC50 of trolox is 13.04 μg/ml. The abilities of anti-oxidation of compound 1, 4, 5, 7, and 10 are all better than the control group, trolox. Among all, compound 10 has the best ability of anti-oxidation (IC50 is 8.75 μg/ml). This study also discovers that the ability of scavenging DPPH free radical is strongly related to the number and the position of hydroxyl.

在清除DPPH自由基的抗氧化能力结果显示，相较於对照组水溶性维生素E之IC50值13.04 μg/ml，多羟基取代之N-色洛冬宁苯甲醯胺衍生物（化合物 1 ~ 10），皆具有相当不错的抗氧化能力，十种醯胺化合物的 IC50值介於8.75 ~ 18.02 μg/ml之间，化合物1、4、5、7、10的抗氧化能力效果皆优於对照组水溶性维生素E的IC50值，其中又以化合物10的效果最佳(IC50值8.75 μg/ml)，而清除DPPH自由基的能力发现与羟基的数量及其位置有关。

Alkyl gallates can also low the extent of lipid peroxidation. To investigate the effects of PG and AG on livers that were injured by tetrachloride, we treamed small mice and fed them with different medicines, The conclusion is that AG and PG could scavenge free radical and protect mice livers from injuring by tetrachloride, AG was more effective than PG. 4. 3 The results of experiment for scavenging free radical of alkyl gallate in vitro showed that alkyl gallates can effectively scavenging free radical, but the parent gallic acid showed little effect. This suggested that introducing of hydrophobic group could significantly improve the anti-oxidative ability of gallic acid derivatives at large extent.

在体内没食子酸烷基酯的抗氧化效果大小顺序为：AG＞PG 4.3 体外清除自由基试验表明：没食子酸烷基酯可有效清除自由基，其能力远远大于母体没食子酸，说明引入脂肪链可相当程度上提高没食子酸衍生物的抗氧化能力。

The scavenging effect of polyphenols extracted from grape seeds such as monomers, dimers and trimers on superoxide and hydroxyl radicals is studied with the ESR spin trapping method. The results are comparable with those obtained from chemiluminescence method. It has been proved that polyphenols extracted from grape seeds have a strong scavenging effect on Oxygen free radicals. Probably this is the reason why drinking some grape wine every day is good for one's health.

用ESR自旋捕集技术研究了从葡萄籽分离的单体、二聚体和三聚体等多酚类物质对羟基自由基和超氧阴离子的精除作用，并与化学发光法的测定结果进行了比较，得到了较一致的结果，证明葡萄籽中多酚类物质对氧自由基的确有较好的清除作用，这很可能是喝少量葡萄酒有利于身体健康的原因。

And the Honeysuckle's leaves extracts have hydroxy free radical scavenging effects as well. The re-extract by ethyl acetate has obviously scavenging activity when its concentration is 1 mg/mL.

抗氧化实验结果表明，金银花叶乙醇提取物具有一定的抗羟自由基氧化活性，其中乙酸乙酯萃取物在1mg/mL的低浓度下就显示出了较好的效果。

The hydroxyl radical scavenging effects of safflower yellow, gardeniayellow, red radish color, purple sweet-potato red color and redcabbage color were detected in vitro with fluorescence spectrophotometry, andthe results make sure that all of the five pigments have some scavenging effects on thehydroxyl radical, though each pigment didn't have the same change trend.

用荧光分光光度法检测红花黄色素、栀子黄色素、红萝卜色素、紫甘薯色素、紫甘蓝色素等五种色素体外清除羟自由基的作用，结果证实SY、GY、RRC、PSPRC、RCC等五种色素对羟自由基都有一定的清除作用，每种色素的变化趋势不完全相同。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。