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羟基肉桂酸衍生物对组蛋白 H3 辐射保护的 ESR 研究 被引量:1
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作者 林维真 屠铁城 +3 位作者 董继荣 姚思德 张加山 林念芸 《辐射研究与辐射工艺学报》 EI CAS CSCD 北大核心 1997年第4期210-216,共7页
应用ESR波谱模拟解析法,研究了77Kγ辐射引发羟基肉桂酸衍生物与组蛋白H3的二元分子复合体系两组分间的电子转移过程。在解析二元复合体系ESR波谱的基础上,计算了二元分子复合体系两组分摩尔比不同的一系列复合体系的自旋... 应用ESR波谱模拟解析法,研究了77Kγ辐射引发羟基肉桂酸衍生物与组蛋白H3的二元分子复合体系两组分间的电子转移过程。在解析二元复合体系ESR波谱的基础上,计算了二元分子复合体系两组分摩尔比不同的一系列复合体系的自旋转移比Rsc。研究发现Rsc与复合体系的摩尔比呈良好的线性关系,这表明羟基肉桂酸衍生物具有较强的夺取蛋白质肽链酰胺羰基阴离子自由基电子和修复蛋白质辐射损伤的能力,这与用羟基肉桂酸衍生物通过电荷转移对生物大分子辐射损伤的保护、修复机理的前期研究结果相符。在研究了辐射引发的组蛋白H3咖啡酸分子复合体系自旋转移比的pH效应基础上,阐明了分子复合体系内蛋白质肽链酰胺羰基与咖啡酸间的氢键是实现体系内分子间电子转移的主要通道。 展开更多
关键词 组蛋白 咖啡酸 芥子酸 辐射保护 酚羟基自由基
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Antioxidant Activity of Ethanol Extract of Pomegranate Seed 被引量:1
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作者 Yuzhong SHI Yuan LU +1 位作者 Benguo LIU Sasa ZUO 《Agricultural Science & Technology》 CAS 2014年第2期304-306,共3页
In this study, the ethanol extract of pomegranate seed was prepared and its antioxidant activities were investigated. It was found the total phenolic content in the extract was as high as 41.791 mg GAE/g. And the extr... In this study, the ethanol extract of pomegranate seed was prepared and its antioxidant activities were investigated. It was found the total phenolic content in the extract was as high as 41.791 mg GAE/g. And the extract showed high antioxidant activity measured as scavenging of DPPH radicals, hydroxyl radicals. It also exhibited strong antioxidant activity in reducing power and Rancimat test. These results demonstrated Pomegranate seeds could serve as a new source of natural antioxidant. 展开更多
关键词 Pomegranate seed ANTIOXIDANT Free radicals
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Oxidation of 4-chloro-3-methylphenol using zeolite Y-encapsulated iron(Ⅲ)-,nickel(Ⅱ)-,and copper(Ⅱ)-N,N'-disalicylidene-1,2-phenylenediamine complexes
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作者 Solomon Legese Hailu Balachandran Unni Nair +3 位作者 Mesfin Redi-Abshiro Isabel Diaz Rathinam Aravindhan Merid Tessema 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第1期135-145,共11页
The degradation of 4-chloro-3-methylphenol(PCMC)using zeolite-encapsulated iron(III),nickel(II),and copper(II)complexes of N,N’-disalicylidene-1,2-phenylenediamine as catalysts,in a heterogeneous Fenton-like ... The degradation of 4-chloro-3-methylphenol(PCMC)using zeolite-encapsulated iron(III),nickel(II),and copper(II)complexes of N,N’-disalicylidene-1,2-phenylenediamine as catalysts,in a heterogeneous Fenton-like advanced oxidation process,was studied.The physicochemical properties of the catalysts were determined using powder X-ray diffraction,thermogravimetric analysis,Brunauer–Emmett–Teller surface area analysis,Fourier-transform infrared spectroscopy,elemental analysis,and scanning electron microscopy.The effects of four factors,namely initial H2O2 concentration,catalyst dosage,temperature,and pH,on the degradation of a model organic pollutant were determined.The results show that at low acidic pH,almost complete removal of PCMC was achieved with the iron(III),nickel(II),and copper(II)catalysts after 120 min under the optimum reaction conditions:catalyst dosage 0.1 g,H2O2 concentration 75 mmol/L,initial PCMC concentration 0.35mmol/L,and 50 °C.The reusability of the prepared catalysts in PCMC degradation was also studied and a possible catalyst deactivation mechanism is proposed.The possible intermediate products,degradation pathway,and kinetics of PCMC oxidation were also studied. 展开更多
关键词 Ship-in-a-bottle method 4-Chloro-3-methylphenol Pseudo-first order DEACTIVATION Hydroxyl radical
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Theoretical study of mechanism and kinetics for the addition of hydroxyl radical to phenol
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作者 WU PengZhen LI Jian +1 位作者 LI ShuJin TAO Fu-Ming 《Science China Chemistry》 SCIE EI CAS 2012年第2期270-276,共7页
The reaction mechanism and kinetics for the addition of hydroxyl radical (OH) to phenol have been investigated using the hybrid density functional (B3LYP) method with the 6-31++G(2dp, 2dr) basis set and the co... The reaction mechanism and kinetics for the addition of hydroxyl radical (OH) to phenol have been investigated using the hybrid density functional (B3LYP) method with the 6-31++G(2dp, 2dr) basis set and the complete basis set (CBS) method using APNO basis sets, respectively. The equilibrium geometries, energies, and thermodynamics properties of all the stationary points along the addition reaction pathway are calculated. The rate constants and the branching ratios of each channel are evaluated using classical transition state theory (TST) in the temperature range of 210 to 360 K, to simulate temperatures in all parts of the troposphere. The ortho addition pathway is dominant and accounts for 99.8%-96.7% of the overall adduct products from 210 to 360 K. The calculated rate constants are in good agreement with existing experimental values. The addition reaction is irreversible. 展开更多
关键词 PHENOL hydroxyl radical addition reaction quantum chemistry calculation transition state theory
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