巯基乙胺修饰电极法测定植物体内超氧阴离子自由基

盐酸羟胺与超氧阴离子自由基反应生成NO2-,通过检测NO2-的生成量,可间接测定超氧阴离子自由基。基于上述原理,建立了一种用巯基乙胺自组装修饰金电极测定生物体系中超氧阴离子自由基的新方法。实验结果表明,在pH4.8的HAc-NaAc缓冲溶液中,修饰电极对NO2-的氧化具有良好的电催化作用,差分脉冲溶出伏安法测定其氧化峰电流与NO2-的浓度在5.0×10-8~1.0×10-4mol/L范围内呈线性关系,其线性回归方程为ipa(μA)=3.726C(μmol/L) 0.0257,相关系数为0.9983;检出限为1.0×10-8mol/L。该法用于玉米幼苗和叶片中超氧阴离子自由基产生速率的测定,结果令人满意。     

Cu,Zn-SOD在银电极上的原位表面增强Raman光谱

本文应用原位共焦拉曼光谱技术观察了Cu ,Zn -SOD分子在经表面增强处理后的银电极上 ,吸附状态随电位跃迁变化的过程。结果表明在 -0 2V～ 0 1V的电位区间内 ,Cu,Zn -SOD分子经由羧酸根离子吸附于银电极表面 ,而在 0 2～ 0 4V电位区间内发生脱附 ,表面吸附的物种改变为缓冲溶液中的磷酸根离子。上述结果为SOD分子在固体电极表面电子传递机制的探索提供了依据。     

Preparation of low-molecular-weight carboxymethyl chitosan and their superoxide anion scavenging activity

Low-molecular-weight carboxymethyl chitosans (CMCTSs) were prepared by oxidative degradation method involving hydrogen peroxide (H₂O₂) without or with microwave radiation. Viscosity determination and end group analysis were applied to measure molecular weights of CMCTSs. Effects of concentration of H₂O₂ and degradation time on molecular weights of CMCTSs were studied. The degradation process of CMCTSs will be accelerated with the aid of microwave radiation and degradation time may be reduced greatly. The superoxide anion scavenging activity of CMCTSs was evaluated by application of flow injection chemiluminescence technology. The 50% inhibition concentrations (IC₅₀s) of CMCTSs A, B, and C (1130, 2430 and 4350 Da) were 10.36, 17.57, and 23.38 mg/mL, respectively. The above results showed that CMCTSs with lower molecular weight had better superoxide anion scavenging activity.     

模拟酶研究进展

综述了近年来模拟酶的研究及进展，着重介绍了配合物模拟水解酶、超氧化物模拟歧化酶的进展及其他模拟酶的合成研究进展。     

土木香内酯的电化学研究

用单扫示波极谱法，在０１ｍｏｌ／ＬＬｉＣｌ中，土木香内酯有两个极谱还原波：Ｐ１（－１４１Ｖ）和Ｐ２（－１５１Ｖ）（ｖｓ．ＳＣＥ），峰Ｐ１的峰高与浓度在４３×１０－７～１２×１０－６ｍｏｌ／Ｌ和１３×１０－６～１５×１０－５ｍｏｌ／Ｌ范围内呈线性关系，可进行定量分析，用标准加入法能作定性分析，其检测限为２６×１０－７ｍｏｌ／Ｌ。测定了中药土木香中总内酯的含量，其结果令人满意。实验证明土木香内酯的电极过程为带有吸附性的不可逆的逐级电子反应过程，另外，还证明了Ｈ２Ｏ２可催化峰Ｐ１和羟基自由基可催化峰Ｐ２，讨论了土木香内酯清除由邻苯三酚自氧化产生的活性氧自由基（Ｏ－·２）的作用。     

Organoiron activation combined with electron- and proton transfer: implications in biology, organic synthesis, catalysis and nanosciences

This Account summarizes the results obtained in our research group on the intra- and intermolecular organoiron activation of substrates by combining the coordination of arenes by CpFe^+/0 and electron and/or proton transfer. The concepts involved are those of electron and proton reservoirs, activation of O₂ by single electron transfer in solution, mimic and inhibition of the reactivity of superoxide radical anion, materials synthesis (for instance fullerene anions), electronic communication between two metals connected by a hydrocarbon bridge, activation of arene ligands for multiple functionalization, giant dendrimer synthesis and electron transfer in catalysis (redox and electron-transfer-chain).     

Immobilized Cytochrome c Sensor in Organic/Aqueous Media for the Characterization of Hydrophilic and Hydrophobic Antioxidants

A method for the characterization of antioxidants is introduced, which allows the measurement of pure hydrophilic and hydrophobic substances as well as complex cosmetic creams. The sensor is based on cytochrome c covalently immobilized on a gold wire electrode working in mixtures of phosphate buffer and organic solvents. It is combined with a superoxide generating enzyme system. The decrease of the superoxide concentration in the test solution by the added antioxidants is detected and used for the quantification of their antioxidative efficiency. Electrochemical properties of immobilized cytochrome c, such as formal potential and heterogeneous electron transfer rate constant, have been investigated in mixtures of aqueous buffer and DMSO, methanol, butanediol, and THF. The maximum organic solvent content for quasi‐reversible electrode behavior was correlated to spectroscopic measurements. The activity of the radical producing enzyme in such media was determined and the radical generation characterized. The antioxidative properties of pure substance such as ascorbic acid and Biochanin A as well as of five anti‐ageing cosmetic creams were studied. This showed also the influence of matrix composition on the efficiency of antioxidative supplements.     

固相复合抗体放射免疫分析法测定人体SOD的含量

本文描述了固相复合抗体放射免疫分析法测定人血清和红血球中超氧化物歧化酶的含量，该法灵敏度为０．５ｎｇ，非特异为２．０±０．６％，批内误差在３．４％～４．２％（ｎ＝９）之间，批间误差在７．０％～７．５％（ｎ＝６）之间，经测定，人血清正常值为２９１±７９（ｘ±ｓ）ｎｇ／ｍＬ，红血球正常值为８６１±９５（ｘ±ｓ）×１０＾－６Ｈｂ。该法灵敏度高、特异性好，简便，快速，适于分析大量样品。     

二十员六氮大环双核铜（Ⅱ）配合物与超氧离子的反应

合成了以2,6-二乙酰基吡啶缩丙二胺为配体,以OH~-、Cl~-、Br~-、I~-、SCN~-及N_3~-为桥基的6种大环双核铜配合物,用光照法研究了这类配合物催化O_2~-的歧化反应的活性,通过顺磁共振波谱,探讨了各种桥基的配合物与O_2~-反应的两种反应机理:催化歧化机理及氧化还原机理。     

Application of stress induces ascorbate peroxidases of S. polyrhiza for green-synthesis Cu nanoparticles

The objective of this study was to assess the effects of stress on physiology/biochemical component of S. polyrhiza and its impact on CuNPs synthesis and bioethanol production. NaCl with RV5 provokes oxidative stress in S. polyrhiza and significantly increase MAD, Proline, H₂O₂, ROS, SOD and APX activity compare to control condition. Starch accumulation in S. polyrhiza was found 354% higher and correspond 4.4 times higher ethanol yield under stress condition compare to control. CuNPs were synthesized with an average size of 23–26 nm by purified fraction of APX having 37 KDa MW, 1.44 IU specific activity. Synthesized CuNPs were stable up to 15 consecutive cycles and potency against wide range of reactive dyes. The maximum remedial efficiency of synthesized CuNPs for COD and BOD was 55263.3 ± 3298.5 mg/m³min. and 30560.3 ± 1987.5 mg/m³min. respectively for RV5 wastewater. 0.072 mg/g of bioethanol was produced from the wet pulp remaining after nanoparticles synthesis. High efficiency of CuNPs and significant production of Ethanol, indicate that the feasibility for circular model for continuous industrial wastewater treatment.