超氧化物歧化酶模型化合物的合成, 表征和活性测定

合成了二(2-苯并咪唑亚甲基)胺(N3)及其四种全新的过渡金属的双核配合物。通过元素分析、红外光谱和紫外光谱对配体及配合物进行了结构表征,利用邻苯三酚自氧化法测定了四种模拟化合物催化超氧阴离子自由基歧化反应的活性。     

两种新型水溶性异黄酮衍生物的合成与抗氧化活性

合成了未见文献报道的水溶性的3'-磺酸钠-4',7-二羧甲氧基异黄酮(L1)和3'-磺酸钠-4'-羟基-7-羧甲氧基异黄酮(L2), 采用IR, UV, ¹H NMR和元素分析对其结构进行了表征, 利用荧光光谱法研究了它们和母体大豆甙元(D)对羟基自由基的清除活性, 用紫外光谱法研究了其对超氧阴离子自由基和1,1-二苯基-2-苦肼基自由基(1,1-diphenyl-2-picrylhydrazyl free radical, 简称DPPH)的清除活性; 并采用量子化学AM1方法在全几何构型优化的基础上进行了电荷布居分析, 计算了它们抽氢反应的生成热(∆H_f), 从而从理论上探讨了目标化合物清除羟基自由基的活性. 实验结果表明本文合成的两种水溶性化合物清除超氧阴离子自由基和DPPH自由基的活性要优于母体大豆甙元, 对于目标化合物清除羟基自由基的活性, 实验和理论结果都显示其清除活性要优于大豆甙元．     

水解珍珠体外抗氧化活性的研究

本文以L-抗坏血酸(VC)为对照组,测定水解珍珠对DPPH自由基、羟基自由基、超氧阴离子自由基和ABTS自由基的清除能力,研究水解珍珠的体外抗氧化活性。结果表明:水解珍珠对DPPH和ABTS自由基具有较强的清除能力,IC_(50)分别为0.07%和0.14%;而对羟基自由基和超氧阴离子自由基的清除能力相对较弱,IC_(50)分别为12.60%和7.65%;其IC_(50)均低于VC,差异具有统计学意义(p0.05)。另外,水解珍珠对DPPH自由基、羟基自由基、超氧阴离子自由基和ABTS自由基的清除率都随着体积分数的增大而显著增加(p0.05)。水解珍珠具备较高的抗氧化能力,可为珍珠资源的开发利用提供理论依据。     

桑色素及其配合物与DNA作用的研究

桑色素 (Morin)是黄酮类化合物 ,具有一定的抗肿瘤活性 [1] .前文 [2 ] 以桑色素为配体合成了 6种过渡金属的配合物 ,并研究了这些配合物与配体对超氧阴离子自由基的清除作用和抗肿瘤活性 .研究表明 ,配合物对超氧阴离子自由基的清除作用明显高于配体 ,桑色素合铜 ( )和桑色素合锌 ( )配合物对 Hep- 2 ,BHK- 2 1和 HL - 6 0癌细胞瘤株的抑制作用强于配体 .配合物具有比单一有效成分更显著的药效 [3 ,4 ] .本文采用荧光方法和电化学方法研究了桑色素和抗肿瘤活性较强的桑色素合铜 ( )、桑色素合锌 ( )与 DNA在生理条件下的相互作用 ,试图…     

天冬酰胺缩2，4-二羟基苯甲醛Schiff碱及其稀土配合物的合成与抗O-2研究

合成了天冬酰胺缩 2 ,4 二羟基苯甲醛Schiff碱及其La、Nd、Er、Dy四种稀土配合物 ,用元素分析、红外光谱、紫外光谱、摩尔电导率等手段进行了结构分析。采用EPR技术对所合成Schiff碱及其配合物的抗超氧阴离子自由基 (O-2 ·)性能进行了探讨 ,结果表明 ,所合成的化合物具有显著的清除O-2 ·的功能 ,而配合物对O-2 ·的清除率高于Schiff碱配体。     

大黄酸金属配合物的合成、表征及抗氧化活性研究

以天然大黄酸为原料合成了三种大黄酸金属配合物. 通过元素分析、摩尔电导、紫外光谱、红外光谱、热重差热、核磁共振氢谱和荧光分析测定配合物的组成和性质. 结果表明配合物组成为ML₂•2H₂O [M＝Cu(II), Fe(II), Mn(II)|L＝rhein(失去1-OH中质子)]. 并对配体和配合物进行了清除超氧自由基(O )、羟自由基(•OH)、DPPH•自由基的对比研究. 抗氧化试验结果表明, 金属配合物抗氧化活性均强于配体.     

铜(Ⅱ)、钴(Ⅱ)Schiff碱配合物的光热性质及其对超氧离子的催化歧化作用

用5-硝基水杨醛与乙二胺缩合,制备了Schiff碱配体.将其与过渡金属Cu(Ⅱ)和Co(Ⅱ)在80℃水浴中搅拌回流1 h,分别形成草绿色和朱红色沉淀,合成出了2种新型的Schiff碱配合物.采用元素分析、红外光谱、紫外光谱、差热热重、荧光光谱、摩尔电导率等分析手段,对配合物进行了表征测试.结果表明,该配合物组成、结构确定,热稳定性强,荧光光谱数据证明配体和配合物都具有荧光性质.用蛋氨酸光照法测定了配体和配合物的生物活性,配体生物活性较低,但形成配合物后活性大增,说明配合物对超氧离子自由基有很强的抑制作用.     

壳聚糖固定化N-亚水杨基甘氨酸锌Schiff碱配合物的研究

利用天然高分子聚合物壳聚糖的轴向配位能力, 首次合成了壳聚糖-N-亚水杨基甘氨酸Schiff碱锌配合物, 通过元素分析、紫外吸收光谱、红外吸收光谱和热分析等方法对配体及配合物进行了表征, 推测了配合物的结构组成. 以Pyrogallol-NBT比色法测定了合成配合物对超氧阴离子自由基的清除能力. 结果表明, 壳聚糖固定化N-亚水杨基甘氨酸锌Schiff配合物对超氧阴离子自由基的清除能力与水杨醛锌Schiff配合物相比大致一样, 但毒性较小.     

天冬酰胺缩2，4-二羟基苯甲醛Schiff碱及其 稀土配合物的合成与抗O-2.研究

合成了天冬酰胺缩2,4-二羟基苯甲醛Schiff碱及其La、Nd、Er、Dy四种稀土配合物,用元素分析、红外光谱、紫外光谱、摩尔电导率等手段进行了结构分析。采用EPR技术对所合成Schiff碱及其配合物的抗超氧阴离子自由基(O     

2，4-二羟基苯甲醛缩硫脲及其配合物的合成与生物活性研究

合成了标题席夫碱及其Cu(Ⅱ)、 Zn(Ⅱ)、 Ni(Ⅱ)配合物，对它们进行了元素分析、UV、IR，对配体进行了质谱和 ¹H NMR等结构表征。还对化合物进行了抑制超氧阴离子自由基及消灭钉螺的生物活性研究。     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

Acid hydrolysis of carboxymethylcellulose of low degree of substitution

Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

Estimation of Kinetic Parameters of Thermal Oxidation of Ilmenite

The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe₂O₃. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.     

Mechanism of action of base-catalyzed oxygenation of phenol derivatives

Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6.     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.