光谱和电化学方法研究自组装纳米簇模拟过氧化物酶

利用细胞色素c与Nafion,通过自组装方式,构建了纳米簇模拟过氧化物酶;利用电子透射显微镜、圆二色谱仪、紫外可见光分光光度仪及电化学工作站等设备测量模拟酶结构变化、酶促动力学参数以及电化学特性;在50 mmol/L Na2HPO4-NaH2PO4缓冲溶液(pH 10.0)中,测得模拟酶米氏常数Km、催化速率及催化效率分别为2.5 μmol/L、0.069 s-1、0.028±0.005(μmol/L)-1s-1,其催化效率为天然辣根过氧化物酶的39％±5％,该模拟酶具有很好的稳定性和活性,能够替代辣根过氧化物酶.该模拟酶可以固定在功能化多壁纳米管与纳米金复合材料修饰玻碳电极上,在50 mmol/L Na2HPO4-NaH2PO4缓冲溶液(pH 7.0)中测得模拟酶与电极之间电子迁移速度常数k8为0.65 s-1.利用循环伏安法测量模拟酶催化浓度为0.02～10 nmol/L的H2O2,其阴极峰电流随H2O2浓度增加而增大,并且得出模拟酶催化H2O2检出限为0.05 nmol/L,电化学表观米氏常数Kmapp为2.3×10-10 mol/L.     

MAP-H2O2-HRP伏安酶联免疫分析新体系的光谱及电化学研究

提出了间氨基酚(MAP)-H2O2-辣根过氧化物酶(HRP)伏安酶联免疫分析新体系.本方法以线性扫描二阶导数伏安法检测HRP催化H2O2氧化MAP的产物,用于游离HRP和各种HRP标记物的测定,灵敏度均高于经典的ELISA显色光度法.测定游离HRP的线性范围为1.0×10-8～1.0×10-6g/L,检测限达3.8×10-9g/L.制备出了HRP催化H2O2氧化MAP的产物纯品,并应用电化学分析,高效液相色谱,元素分析,紫外-可见光谱,红外光谱,1H核磁共振谱,13C核磁共振谱及质谱等技术对体系酶促反应进行了深入的研究.在选择的酶促反应条件下,生成的产物为2-氨基-5-[(3-羟苯基)氨基]-2,5-环己二烯基-1,4-二酮.提出了酶催化反应机理及其产物的电极还原过程.     

血红蛋白作为催化剂高灵敏测定过氧化氢

用血红蛋白作为过氧化物酶的替代物,用于催化H2O2氧化对甲基酚的反应体系.研究发现,血红蛋白作为过氧化物酶的替代物,其催化活性比Hemin、β-CD-Hemin等过氧化物模拟酶要高.建立了高灵敏测定痕量H2O2的荧光分析法.该法的线性范围为3.19×10-8～3.19×10-6 mol/L,检出限为8.85×10-10 mol/L.用于雨水中H2O2的测定,结果满意.     

以邻氨基酚为底物的伏安酶联免疫分析体系酶促反应的研究

辣根过氧化物酶 (HRP)催化H2 O2 氧化邻氨基酚的酶促反应与邻氨基酚的氧化产物的电极还原反应相偶合的伏安酶联免疫分析新体系具有很高的灵敏度 ,测定HRP的检出限为 6 .0× 1 0 -10 g/L ,线性范围为 1 .0× 1 0 -9～ 4.0× 1 0 -6g/L .制备出了HRP催化H2 O2 氧化邻氨基酚的产物纯品 ,并应用电化学分析、高效液相色谱、紫外 可见光谱、红外光谱、13 C核磁共振谱、1H核磁共振谱、质谱、元素分析等技术对体系酶促反应进行了深入的研究 .在所选择的酶促反应条件下 ,生成的产物为 3 氨基吩嗪 .提出了酶促反应及其产物的电极还原过程 .     

高灵敏荧光增敏法测定抗坏血酸

基于痕量抗坏血酸对模拟酶β-CD-hemin催化H2O2氧化对甲基酚体系的产物荧光的增强作用,提出了一种新的测定抗坏血酸荧光分析方法.方法具有很高的灵敏度和较好的选择性,其线性范围为1×10-9～8×10-8mol/L;检出限可达3.45×10-10mol/L.用于实际样品的分析,获得满意结果.     

方波伏安法测定孔雀石绿上染率

采用循环伏安法和方波伏安法研究了阳离子染料孔雀石绿(MG)在H2SO4底液(pH 1.0)中的电化学行为.在0.1 V/s的扫描速率下,MG在碳糊电极上显示一个不可逆氧化峰:0.82 V(Pa,2);一对准可逆氧化还原峰:0.51 V(Pa,1)、0.48 V(Pc)(Ep vs.SCE).在0.05～0.9 V/s的扫速范围内,3个峰的峰电流与扫速的平方根都成正比,表明MG的电氧化还原过程均受扩散控制.计时库仑法测得MG的扩散系数为2.31×10-7cm2/s,表面覆盖度是1.18×10-11mol/cm2.还原峰Pc的峰电流与MG的浓度在8.00×10-6～1.00×10-4 mol/L范围内呈线性关系,检出限为6.6 μmol/L(S/N=3),染色工艺中常用的匀染剂"平平加O"和MG染色体系中常见的无机离子不干扰测定.本方法用于测定MG上染腈纶的上染率,结果与分光光度法一致.     

2-氨基-3-羟基吡啶-过氧化氢-辣根过氧化物酶伏安酶联免疫体系分析人血清癌胚抗原

以氮杂环化合物为电化学分析底物的2-氨基-3-羟基吡啶-H2O2-辣根过氧化物酶(HRP)伏安酶联免疫体系测定人血清癌胚抗原(CEA).HRP催化H2O2氧化2-氨基-3-羟基吡啶的酶促反应产物,在缓冲液中-0.36 V处产生一个灵敏的伏安还原峰,借助此峰可以测定游离的HRP,进而可用于以HRP为标记物的酶联免疫分析.对酶促反应条件和测定条件的优化反应条件为:以B-R缓冲液(pH 6.0)为反应介质,在10 mL总反应液中含有1.0 mL 0.2 mol/L B-R缓冲液、3.0 mL 8.0 mmol/L 2-氨基-3-羟基吡啶溶液以及1.5 mL 0.5 mmol/L H2O2溶液,反应温度37 ℃,反应时间30 min.最佳测定条件为:B-R缓冲液(pH 7.0)为支持电解质,在10 mL总测定溶液中含有5 mL上述总反应液、1.0 mL 0.2 mol/L B-R缓冲液.测定仪器条件:起始电位0.00 V,终止电位-0.80 V,电位扫描速度400 mV/s,滴汞静止时间7 s.在最佳的反应条件和测定条件下,新体系测定游离HRP的线性范围为4.0×10-4～1.0 μg/L; 对HRP的检出限为0.12 ng/L.新体系对CEA测定的线性范围为0.50～80.0 μg/L; 检出限为0.50 μg/L.为经典ELISA法的检出限的1/10.     

循环连续流动分析法测定辣根过氧化物酶的活性

基于H2O2-辣根过氧化物酶(HRP)-邻苯二胺(OPDA)催化反应体系,建立了测定游离及固定化HRP酶活性的循环连续流动分析法(CCFA).CCFA实现了反应液、反应过程的循环连续检测.用CCFA法对酶催化反应条件进行研究,得到的最佳反应条件是:pH 5.0,反应温度27 ℃, 66.0 μmol/L H2O2 , 2 mg/L OPDA,缓冲液为0.1 mol/L柠檬酸-柠檬酸钠缓冲液; 测定游离HRP的线性范围为0～10 U/L,检出限为0.21 U/L,RSD＜1.03%.使用CCFA法测定了固定化HRP的活性,并对HRP酶促动力学进行了研究,得到的游离HRP的米氏常数为0.078 mmol/L,最大反应速度为0.26 mmol/(L min),催化常数为5.2 × 104 min-1.CCFA法操作简便、准确度高、节省试剂、易于实现自动化.     

巯基丁二胺镍(Ⅱ)自组装单分子层H2O2传感器研究

采用巯基丁二胺镍(Ⅱ)(NiL-SH)自组装单分子层修饰金电极,制得测定H2O2的电流型生物传感器.NiL-SH在电极表面有一对可逆的氧化还原峰.传感器对H2O2的还原显示出快速电催化响应(＜10 s),采用电子扫描电镜(SEM)和光电子能谱(XPS)对电极表面进行了表征,且计算了其自身电化学反应性质.研究了各种因素如pH、工作电位等对传感器响应电流的影响.循环伏安法测定H2O2的线性范围为5.0×10-6～3.0×10-3 mol/L(r=0.999),检出限为2.0×10-6 mol/L.该电极显示出模拟酶特性,测定米氏常数KMapp＝2.78 mmol/L.对传感器的稳定性,灵敏度和选择性进行研究,并应用于实际样品测定.     

辣根过氧化物酶催化过氧化氢氧化隐性亮绿显色反应的研究

以隐性亮绿 (RBG)为氢供体底物 ,研究了辣根过氧化物酶 -H2 O2 -RBG显色反应体系的酶催化特性。在 p H 5.0～ 6.0的条件下反应形成的酶催化产物亮绿 (BG)于 63 0 .6nm处有最大吸收 ,该显色反应测定 H2 O2 的表观摩尔吸光系数为 5.64×1 0 4 L·mol- 1·cm- 1,线性范围为 3 .55× 1 0 - 8～ 6.0× 1 0 - 6 mol/ L,检出限为 3 .55×1 0 - 8mol/ L。方法用于雨水中痕量 H2 O2 的测定 ,结果满意     

4-溴代苯酐的合成新方法

将4-硝基邻苯二甲酰亚甲胺（4-NPI）用铁粉还原为4-氨基邻苯二甲酰亚甲胺 ，再在氢氧化钠水溶液中水解成4-氨基邻苯二甲酸钠。4-氨基邻苯二甲酸钠在氢溴 酸中经Sandmeyer反应合成4-溴代苯酐。产品纯度高，是合成4-溴代苯酐的一个比较 理想的方法。     

SO2-4/SnO2催化剂的制备及其对苯硝化反应的催化活性

采用(NH4)2SO4溶液浸渍法制备了一系列SO2-4/SnO2催化剂(Cat-n,n=5,10,15,20),其结构经IR表征.以Cat-10(焙烧温度500℃)催化苯液相硝化反应的研究结果表明,引入SO2-4后催化剂的活性显著增加,硝基苯产率63.8%.     

Studies on New Steroidal Saponins from Allii macrostemonis Bulbus and Their Antitumor Activities Design and Synthesis of Novel Bispecific Molecules for InducingBRD4 Protein Degradation

Proteolysis targeting chimeras(PROTACs) are bispecific molecules containing a target protein binder and a ubiquitin ligase binder connected by a linker. Recently, some heterobifunctional small molecule bromodomain-containing protein 4(BRD4) degraders based on the concept of PROTACs were designed to induce the degradation of BRD4 protein. Herein, we synthesized a new class of PROTAC BRD4 degraders. One of the most promising compound 22f exhibited robust potency of BRD4 inhibition with IC₅₀ value of (9.4±0.6) nmol/L. Furthermore, compound 22f potently inhibited cell proliferation in BRD4-sensitive cell lines RS4;11 with IC₅₀ value of (27.6±1.6) nmol/L and capable of inducing degradation of BRD4 protein at 0.5―1.0 μmol/L in the RS4;11 cells. These data establish that compound 22f is a potent and efficacious BRD4 degrader.     

基于脂肪酸的漂浮液滴固化分散液液微萃取-高效液相色谱法联用测定酒类样品中的4-乙基苯酚和4-乙基愈创木酚

建立了基于脂肪酸的漂浮液滴固化分散液液微萃取（FA-DLLME-SFO）方法,与高效液相色谱联用检测了酒类样品中的4-乙基苯酚和4-乙基愈创木酚。该方法萃取时间仅需4 min,仅需脂肪酸、氨水和硫酸3种对环境友好的试剂。对影响方法萃取效率的因素（包括样品的体积、萃取剂的种类和用量、氨水和硫酸的体积以及盐的加入量）进行了详细的考察。在最佳萃取条件下（10 mL样品,100 μL辛酸萃取剂,110 μL 25%～28%（质量分数）的氨水,0.8 mL 98%（质量分数）的浓硫酸,3.0 g NaCl）,4-乙基苯酚和4-乙基愈创木酚在0.02～1.0 mg/L范围内呈良好的线性关系,相关系数分别为0.9997和0.9999,相对标准偏差（n=3）分别为6.2%和3.5%,检出限分别为6.33和5.81 μg/L,富集倍数分别为79和86。在啤酒和白葡萄酒样品中,加标回收率为81.4%～108.7%,相对标准偏差（n=3）小于8.9%。该方法简单、对环境友好,可用于酒类样品中4-乙基苯酚和4-乙基愈创木酚的检测。     

Synthesis of New Multibranch Chromophores with Strong Light-emitting in Solution and in PMMA Film

Three new chromophores with triphenylamine as molecular focal point bearing one,two, or three 4-(n-butyloxystyryl) group(s) at the periphery respectively, (named as T1, T2, and T3) have been synthesized and characterized. It is interesting to find that the fluorescence quantum yield increases from T1 (0.489), to T3 (0.535), and to T2 (0.628) in cyclohexane, meanwhile the lifetime for T3 is shorter than T1 and T2, which is an important characteristic for applications in light emitting diode. Also PMMA (polymethyl methacrylate) film doped with T3 gives stronger fluorescence than T1, and T2. Cyclic voltammetry showed that T3 exhibited lowest oxidation potential of-0.52 V vs SCE, suggesting its better hole-transport property.     

Synthesis of (diorgano)chloro(4-chlorobutoxy)silanes

Some novel (diorgano)chloro(4-chlorobutoxy)silanes were obtained by the reaction of dichlorodiorganosilanes with tetra hydrofuran in the presence of chloroplatinic acid.Translated fromIzvestiva Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 943–945, April, 1996.     

Beiträge zur Chemie des Phosphors. 236. Über einige physikalische und chemische Eigenschaften von Diphosphan(4)

Contributions to the Chemistry of Phosphorus. 236. On Several Physical and Chemical Properties of Diphosphane(4) The density of diphosphane(4) has been measured between ?78°C and +18°C and the value d₄²⁰ = 1.014 · 0.002 extrapolated. The refractive index of P₂H₄ was determined to be n²⁰ = 1.66 ± 0.01. The surface tension at 0°C and ?50°C was measured to be σ = 34 and 42 dyn · cm^?1, respectively. In the UV absorption spectrum, gaseous P₂H₄ exhibits a broad absorption band at λ_max = 2 220 Å, in n-hexane solution, this band is shifted somewhat to shorter wave-lengths. The molar extinction coefficient was determined to be ? ≈? 900 1 · mol^?1 · cm^?1. As a result of photolytic decomposition, absorptions for PH₃ and more phosphorus-rich hydrides also occur. The solubility behavior of P₂H₄ in various organic solvents and the stabilities of the resultant solutions have been investigated. At 0°C, the solubility of diphosphane(4) in water was found to be ± 035 ± 0.003 g P₂H₄/100 g solution and that of water in diphosphane(4) to be 43.2 ± 1.6 g H₂O/100 g solution. The system diphosphane(4)/methanol also exhibits a miscibility anomaly. The IR spectra of liquid P₂H₄ and of its solutions in various solvents revealed, in accord with the results of nuclear magnetic resonance spectroscopy [7], that diphosphane(4) is practically not associated. Weak interactions through hydrogen bridging bonds occur with pyridine and methanol in which P₂H₄ serves as the proton donor and, in the latter case, also as proton acceptor. For the thermolysis of diphosphane(4), it has been found that the primary step comprises a disproportionation with inter-molecular elimination of PH₃ and formation of triphosphane(5). With further progress of the thermolysis, in dependence on the reaction conditions, mixtures of various phosphanes of differing composition are formed. Photolysis gives rise to phosphane mixtures having similar compositions. With aqueous silver salt and iodine solutions, diphosphane(4) reacts as a reducing agent; with sodium hydroxide solution, it reacts by a slow disproportionation as well as by formation and degradation of the subsequently formed polyphosphides. On reaction with triphenylmethyl, triphenylmethane and a yellow solid of varying composition are formed. The reaction of diazomethane with diphosphane(4) leads to the preferential insertion of the carbene in the P? P bond and formation of methylenebis(phosphane).     

含硫醚和二氮杂萘酮结构聚芳醚酮的合成与性能

通过 4 ,4′ 硫代二酚 (TBP)、4 (4 羟基苯基 ) 2 ,3 二氮杂萘 1 酮 (DHPZ)与 4 ,4′ 二氟二苯酮 (DFK)反应合成出不同组分的高分子量共聚芳醚酮 .对聚芳醚酮的结构进行了FT IR、1 H NMR和1 3C NMR表征 ,表明共聚酮为无规结构 .对共聚芳醚酮的热性能、结晶性能、拉伸性能、溶解性能进行了测试 ,结果表明随硫醚结构含量的增加 ,共聚醚酮的玻璃化转变温度降低 ,材料韧性增强 ,溶解性能变差 ,所得的共聚物为无定型态 ,但由TBP和DFK制得的均聚醚酮为半结晶性     

Synthesis and mesomorphic properties of 4-(4-bromopropyloxy)-4’-(4-alkyloxybenzylidene)anilines

This article describes the preparation and liquid crystalline properties of a new homologous series of 4-（4-bromopropyloxy）-4’- （4-alkyloxybenzylidene）anilines in which the phenyl ring is armed by a bromopropyloxy chain.The thermal behavior and mesomorphic properties of the synthesized compounds were studied with particular attention given to the correlation between their phase transition temperatures and anisotropic change influenced by molecular structure.All the members displayed enantiotropic smectic phase except for the homologue with the longest alkyloxy chain(R = C₁₈H₃₇),exhibiting only monotropic characteristic. The presence of bromine atom from the propyloxy side chain is found to be capable of altering and influencing the mesomorphic properties.