Construction of the Skeleton of Phthalascidin, Mechanism of the Formation of the Key Tricyclic Lactam Intermediate

Phthalascidin is a structurally simplified version of Et-743, which is a potent anti-tumor marine natural product isolated from Ecteinascidia turbinata. Its antiproliferative activity is greater than that of the agents taxol, camptothecin, adriamycin, mitomycin C, cisplatin, bleomycin, and etoposide by 1-3 orders of magnitude. An elegant synthesis of Et-743 and phthalascidin has been reported by E. J. Corey and co-workers1,2. As part of our continuing program, we have also engaged in dev…     

Determination of nitrite by inhibition of the chemiluminescence of acriflavine in a flow-injection assembly

The indirect determination of nitrite was performed with a flow-injection assembly on the basis of the inhibition of the analytical output obtained in a luminometer by oxidation of acriflavine. The acriflavine solution merged with the nitrite and the resulting mixture was injected into a pure water stream. This solution merged with the oxidant solution (potassium permanganate in sulfuric acid medium) and the resulting chemiluminiscence was affected (inhibited) by the presence of nitrite after reaction with the aminoacridine. The method was applicable over the range 10-800 microg l(-1) of nitrite with a correlation coefficient of 0.9960. The relative standard deviation was 1.4% and the throughput was 76 samples h(-1). The influence of foreign substances was also tested. A solid-phase reactor, filled with Amberlite IRA-900, was inserted in the assembly for the on-line preconcentration of nitrite; the analytical output resulted in an increase of up to 11.5-fold. The method was applied to the determination of nitrites in residual waters, industrial formulations and soil samples.     

抗酮洛芬多克隆抗体的制备及其间接竞争ELISA检测方法的建立

分别将酮洛芬与牛血清白蛋白(BSA)及卵清蛋白(OVA)偶联制得免疫原和包被原,经过免疫新西兰白兔制备多克隆抗体,抗体经纯化后效价为1:128000。使用自制的抗体,建立了测定酮洛芬的间接竞争酶联免疫吸附(ic-ELISA)新方法。ic-ELISA的线性范围为0.010～10.0μg/L,IC50为0.235μg/L,最低检测限为0.0040μg/L,线性回归方程为y=-22.97ρ+104.5(R2=0.980),与布洛芬、双氯酚酸的交叉反应率均小于4%,方法可用于水体中酮洛芬的检测。     

Electrodialysis of Hydrosols of Ultradispersed Diamonds

The electrical conductivity of hydrosols of ultradispersed diamonds was studied. The electromembrane method for cleaning and concentrating of ultradispersed diamonds in hydrosols was considered. The influence exerted by the concentration of the dispersed phase on the electrical characteristics of the cleaning process was analyzed. A mathematical relation making it possible to evaluate the output characteristics of the process and to determine the geometrical characteristics of the apparatus was proposed.     

固定化脂肪酶活性的X射线微区分析

利用X射线微区分析的方法，对吸附交联法得到的固定化脂肪酶的微观活性进行了分析。结果表明：以合成出的大孔吸附树脂为固定化酶栽体，酶活较高，活性脂肪酶分布较均匀。并得到了固定化脂肪酶的活性定位的最佳条件。     

悬浮液气-液界面二元胶体颗粒的漂浮组装机理

提出一种在悬浮液气-液界面漂浮组装亚微米单分散聚苯乙烯(PS)微球和纳米SiO2颗粒二元胶粒晶体的新方法, 并系统研究了漂浮组装机理. 研究表明, 聚苯乙烯微球和二氧化硅两种胶体颗粒在悬浮液气-液界面的漂浮组装是以PS微球的组装为主导的. 在一定PS微球相浓度范围内, 悬浮液中PS 微球与SiO2颗粒的初始体积配比基本不影响PS微球有序组装的形成. PS微球粒径在150-500 nm时易于形成有序排列, 较小或较大粒径的PS微球难以形成有序排列. SiO2颗粒的组装是一种以PS微球为“基底”的沉积过程. 二元胶粒晶体中SiO2颗粒的体积分数由其在混合悬浮液中的相浓度所决定.     

交联酶聚集体与仿生硅化技术结合制备固定化脂肪酶

将交联酶聚集体(CLEAs)与仿生硅化技术相结合,制备了交联脂肪酶Candidasp.99-125杂化生物催化剂.以京尼平为交联剂,在最佳条件下制得的脂肪酶CLEAs的酶活达771U/g,回收率达75%;保护剂聚乙烯亚胺(PEI)与Candidasp.99-125脂肪酶共沉淀制备P/CLEAs,其酶活达897U/g,回收率约88%;利用PEI的诱导作用,在P/CLEAs表面形成氧化硅涂层,制得的脂肪酶CLEAs(Coated-CLEAs)显示出良好的稳定性,特别是其抗蛋白酶水解能力、有机溶剂耐受能力、重复使用性能等方面明显提高.     

空气-乙炔火焰原子吸收法测定硫铁矿中的砷

研究了空气-乙炔火焰原子吸收法测定硫铁矿中砷的方法,讨论了其测试条件和共存元素的干扰,样品采用酸浸溶解、直接上机测定。结果表明,该法具有操作简单、快速、火焰温度较高等优点,线性回归方程及相关系数分别为:A=0.003 20 C 0.009 77,r=0.999 3。     

HPLC study of tissue distribution of loganin in rats

A rapid, sensitive and selective high performance liquid chromatography (HPLC) method was developed and validated for determination of loganin in rat tissues. Samples were prepared based on a simple protein precipitation. Separation of loganin was achieved on a reversed-phase C(18) column (250 x 4.6 mm, 5 microm) with a mobile phase consisting of acetonitrile and water (16:84, v/v) at a flow rate of 1.0 mL/min. The detection wavelength was set at 236 nm and the temperature of the column was kept at 30 degrees C. The method was applied to study tissue distribution of loganin in rats after a single administration of loganin at a dose of 20 mg/kg. The highest level was observed in kidney, then in stomach, lung and small intestine. The lowest level was found in brain. The peak levels were attained at 90 min in most tissues. It was indicated that kidney was the major distribution tissue of loganin in rats, and that loganin had difficulty in crossing the blood-brain barrier. It was also found there was no long-term accumulation of loganin in rat tissues.     

紫外分光光度法测定苯基硅油的苯基含量

采用水解缩合法合成了苯基硅油,并进行傅立叶红外(FTIR)、氢谱(1H NMR)表征.根据氢谱的积分,计算得产品的苯基含量.基于苯基基团在紫外区的特征吸收,以自制苯基硅油为标准品,建立了一种紫外分光光度法测定苯基硅油中苯基含量的方法.以二氯甲烷为溶剂,264 nm为最大吸收波长,苯基浓度在0.277×10-3～2.13×10-3 mmol· mL-1范围内,符合比尔定律,其R2 =0.99946.实际样品测定的相对标准偏差小于1.81％,平均回收率为99.0％左右.该方法线性相关性好、精密度及准确度高、便捷、成本低,适合科研及工业生产中苯基含量的日常分析.     

炼焦煤的官能团结构分析及其黏结性产生机理

以11种炼焦煤为研究对象,分别进行FT-IR和黏结指数G测试。采用Peak Fit软件对FT-IR谱峰进行分峰拟合和定量计算,研究炼焦煤特征官能团含量与其黏结性间的关系。结果表明,煤黏结性大小与其FT-IR吸收峰密切相关,特别是3 000-2 800和3 700-3 000 cm-1两个吸收带;脂肪族结构是煤黏结性形成的主要决定因素,通常脂肪链越短或支链化程度越高,越有利于煤的黏结性形成;含-OH(或-NH)的氢键缔合结构可以与脂肪链协同作用,共同决定煤的黏结性能。不论煤分子有多大,只要是结构单元缩合度较小而作为桥键的脂肪链较多的结构形式,在热解过程中就会生成大量适度分子量、以结构单元为基元的液相物质。氢键是煤中主要的分子间作用形式,当若干形成氢键的官能团聚集缔合时,其相互作用会更强,甚至会形成类似超分子的结构;在形成胶质体阶段,这类氢键缔合的结构也会被打破,并形成以胶质体液相为主的物质。这些液相物质的存在,有利于胶质体的流动、黏连和固化成为半焦,从而最终获得优越的黏结性。     

镉溶液标准物质的研制

介绍镉溶液标准物质的研制过程。以高纯镉为原料,1%硝酸溶液为基体,利用重量–容量和一步稀释法制备镉溶液标准物质。分别采用F检验和回归曲线法对研制的标准物质进行均匀性和稳定性考察。采用电感耦合等离子体发射光谱法与国家一级标准物质比对定值,并对镉溶液浓度量值进行不确定度评定。利用原子吸收分光光度法和电感耦合等离子体发射光谱法对研制的标准物质与国家二级标准物质进行比对。结果表明,研制的镉溶液标准物质的定值结果为100μg/m L,相对扩展不确定度U_(rel)=1.0%(k=2)。该标准物质量值准确且具有溯源性。     

Evaluation of permselectivity of a liquid anion-exchange membrane by diffusion dialysis

The permselectivity of liquid anion-exchange membrane containing high molecular weight amines to some organic and inorganic anions was evaluated by diffusion dialysis. The relative ion exchange constant of the membrane solution was determined by a solvent extraction procedure. The apparent diffusivity of several ion pairs through a supported liquid membrane was determined by the time lag method. The permselectivity to the anions was approximately consistent with the Hofmeister anion series and it was correlated with the diffusivity of ion pairs in the membrane and the relative ion exchange constant at the membrane-solution interface. The relative ion exchange constant was found to be the dominant factor in permselectivity. The concentration profile of ion pairs in a stack of liquid membranes was linear with the distance at steady state.     

10,12—双炔廿三酸盐的LB膜特性研究

本文合成了10,12-双炔廿三酸,并用其在Si、SiO_2、CaF_2等基片上沉积了LB膜,结果表明,10,12-双炔廿三酸的镉盐成膜更稳定。这种LB膜在紫外光辐照下很快聚合,聚合前后的紫外-可见吸收光谱发生规律性的变化,并保持层状结构,等同周期稍变。通过红外吸收的二向色性分析,确定了该分子的取向。     

制备条件对稀土掺杂TiO2物理性质和光催化降解吡唑草胺性能的影响

多相光催化是一种非常有效的降解各种水污染物的方法.本文以稀土(镝和镨)掺杂的TiO2为光催化剂,考察了制备条件对其物理性质和光催化性能的影响.采用溶胶-凝胶法和不同条件(反应温度450,550,650oC;反应时间4,8,12 h)的固态反应法制备了TiO2样品.运用X射线衍射分析了该样品的晶相,发现只存在锐钛矿相,并得到Raman光谱的证实.同时采用扫描电镜观察了样品的结构和粒径;以BET法计算了其比表面积;运用紫外-可见光漫反射光谱测得了样品的带隙能量.通过测量紫外光照射下常用除草剂吡唑草胺的降解速率评价了样品的光催化活性,反应过程中吡唑草胺的浓度用高效液相色谱分析.结果表明,稀土掺杂使得TiO2吸收边红移,并提高了其光催化活性;制备时最优的固态反应条件为550oC反应8 h.     

高镍含量二元金属柱撑粘土的制备

报道了一种制备多元金属柱撑粘土的新方法－生长法。将此法与通用的同晶取代法制得的样品进行比较，发现前者的镍含量远大于后者。此种交联物的底面间距约１．７ｎｍ，样品在ＩＲ谱中７４４ｃｍ＾－１处出现的吸收谱带可作为柱状物存在的标识，插入层间的柱状物中镍以六配位形式存在，是一种尖类晶石结构，处于这种状态的镍要比同晶取代进入Ｊｏｈａｎｓｓｏｎ离子中的镍更难于被还原。     

植物油酸新戊二醇对苯二甲酸复合酯的合成及性能

用新戊二醇(NPG)和对苯二甲酰氯(TPA)反应生成“低聚物”中间体,当n(NPG)/n(TPA)由2.4增加至3.0时,中间体的聚合度(m)在3.5~1.45之间,收率75.5%。再将中间体与油酸、菜籽油酸进行酯化得到复合酯,收率88.5%。结果表明,复合酯的粘度随着分子量的增大而增大,粘度指数大于125,凝点低于－27℃,氧化稳定性随分子量的增大而提高,生物降解率＞70%,最大无卡咬负荷(PB)为784N,磨斑直径0.41mm,热分解温度＞250 ℃,因此植物油酸新戊二醇对苯二甲酸复合酯是性能良好的绿色润滑剂。     

Determination of bencyclane in human plasma by means of capillary gas chromatography and nitrogen-phosphorus selective detection

A sensitive and specific method for the determination of bencyclane in human plasma is presented. Bencyclane was extracted from human plasma with two 3-ml volumes of isooctane and was shaken for 10 min. The organic phase was separated and evaporated to dryness at 40 degrees C under a nitrogen stream. The residue was dissolved and an aliquot was injected into the gas chromatograph. The separation was performed with a DB-17 column with helium as the carrier gas. Nitrogen-selective detection was performed. The quantification was performed with the signal output. The limit of detection was 1 ng/ml.     

Thermodynamics of adsorption of polybutadiene on alumina and silica gel: effect of temperature and solvent

The adsorption of polybutadiene (PBR) on alumina and silica gel was studied at different temperatures from cyclohexane and toluene solutions. It shows that the adsorption process was dependent on temperature and solvent. The adsorption isotherm and the thermodynamic quantities of adsorption were determined and it was observed that the adsorption process from both solvents was similar and the amount of adsorption increased as temperature decreased. The silica gel-cyclohexane system was more exothermic than all other systems and was also relatively more ordered.     

Cardiovascular effects of mycelium extract of Ganoderma lucidum: inhibition of sympathetic outflow as a mechanism of its hypotensive action

In an effort to understand the mechanism of cardiovascular actions of Ganoderma lucidum which was cultivated in Korea, the mycelium was isolated for a large-scale culture. Water extract of the mycelia was evaluated for its cardiovascular activity in anesthetized rabbits and rats. The left femoral artery and vein were cannulated for the measurement of arterial pressure and subsequent delivery of drugs. The left kidney was exposed retroperitoneally and a branch of the renal nerve was used to integrate renal efferent or afferent nerve activities. The extract decreased systolic and diastolic blood pressure, which was accompanied by an inhibition of renal efferent sympathetic nerve activity. The extract did not decrease heart rate in these animals, although there was clear hypotension in the extract dose dependent manner. This suggests that the hypotension induced by the treatment of the extract was secondary to the primary effect of the extract in the central nerve system, which suppressed the sympathetic outflow. Therefore we concluded that the mechanism of hypotensive action of Ganoderma lucidum was due to its central inhibition of sympathetic nerve activity.