核外氮杂甾体的合成及其抗肿瘤活性研究进展

合成氮杂甾体并评估其生物学活性是甾体化学和甾体新药研发领域的热点之一.通过总结近期发表的相关文献,重点介绍核外氮杂甾体如甾体螺吲哚酮类化合物、三氮唑连接的甾体杂合体及天然氮杂甾体的合成及其抗肿瘤活性的最新进展.     

具有特殊甾核结构甾体化合物的合成及生理活性研究进展

改变甾体的甾核结构,在甾核或支链中引入不同的官能团,可以得到一些具有不同生理活性的化合物.按照不同类型甾核结构分类,结合本课题组在具有特殊甾核结构甾体化合物的合成和生理活性研究方面所取得的一些成果,对近年来具有A-失碳甾体化合物、B-失碳甾体化合物及C-失碳-D-增碳甾体化合物的合成及生理活性进行讨论,并展望了此类化合物的发展趋势及应用前景.     

具有抗肿瘤活性甾体氮芥类化合物的研究进展

本文按照甾体的甾核结构对甾体氮芥化合物进行分类,综述了近年来新合成的甾体氮芥类化合物及其衍生物的抗肿瘤活性及研究进展,并对此方面的发展趋势和应用前景作了展望。     

网络版论文摘要

w2011006甾体合铂配合物设计合成与抗肿瘤活性研究进展 摘要 自从发现顺铂具有抗癌活性之后,人们设计合成了许多铂类抗癌药物。甾体激素在生命体中起着重要的作用,铂与甾体配位得到的甾体合铂配合物往往也具有很好的抗癌活性     

核外氮杂甾体的合成及其抗癌活性研究进展

含氮甾体的合成是近年来甾体化学研究的热点之一。本文按照含氮甾体的生理活性和结构特征，分5个方面(胆汁酸类、雌甾类、雄激素类、孕烯甾类及其它类)综述了其合成和抗癌活性的研究进展。     

胆固醇氢亚磷酸酯缀合物的简便合成

许多甾体磷酸酯具有重要的生物活性,例如脂质膜和甾体激素中的甾体磷酸酯缀合物.利用一些甾体类物质的体内转运机制,可以增加药物的靶向性,同时将糖和甾体相连可以增加甾体类药物水溶性.胆固醇是许多生物膜的关键结构单元,同时又是甾体激素和胆酸的生物合成前体.本文报道一种简便的合成胆固醇氢亚磷酸酯缀合物的合成方法,从这些氢亚磷酸酯出发可以进一步得到许多具有生物学意义的磷酸酯缀合物.     

新型甾体缀合物的设计合成及活性研究*

甾体化合物是一类生物体中广泛存在并起重要功能的生物分子。其特殊结构使这类化合物具有亲脂性,膜亲合性以及与低密度脂蛋白的特异性结合等性能。利用这些特性设计合成各种药物分子的甾体缀合物,可增加药物分子的脂溶性,提高跨膜渗透能力,在特定组织中的分布以及甾体缀合物自身具有独特的生物活性,对探索新型生物活性分子具有重要意义。本文介绍了近年来在设计合成新型甾体缀合物领域的研究进展,包括甾体药物缀合物、含磷甾体缀合物、作为离子通道和分子载体的缀合物及甾体二聚缀合物等。     

甾族化合物不对称合成的研究XV: 光学活性3-氧杂-A-失碳甾族化合物的合成

我们在寻找新的甾体口服避孕药的研究中,设计了A-失碳-3,9(10)-二烯-18-甲基甾体(1)作为全合成研究的目的物.前文已报道从5’-甲基呋喃二噻烷阴离子2b与消旋甾体CD环合成原3b的共轭加成,合成了两个新的消旋3-氧杂-A-失碳甾体4b和5b.本文报道     

呋喃甾烷型皂甙的研究进展

综述了呋喃甾烷型皂甙(双糖链甾体皂甙)的结构特点、化学性质、生理活性和生源合成。列举了1966～1999年发现的双糖链甾体皂甙,共214个。     

具有生理活性的甾体酰胺类化合物

在甾体的甾核或支链上引入不同的官能团后可得到不同生理活性的化合物,它们有可能会成为人类治疗不同疾病的药物,因此甾体药物除了作为传统激素类药物使用外,在抗肿瘤药物、抗炎药物中的应用也成为甾体的重要研究内容之一。含有酰胺官能团的甾体化合物具有很好的生物活性。本文按照酰胺基团在甾体酰胺化合物中的位置进行分类,同时结合本课题组在甾体酰胺化合物的合成和生理活性研究方面所取得的一些成果,概述了近几年来新合成及发现的甾体酰胺类化合物及其衍生物的生理活性及研究进展,包括作为抗肿瘤药物的甾体酰胺化合物的设计、筛选、对5α-还原酶的抑制作用、抑制肿瘤细胞生长增殖活性及抗菌作用,并对此方面的发展趋势、应用前景作了展望。     

电感耦合等离子体质谱法快速测定苦荞茶中铜、铅、镉、钴、镍

建立了用硝酸-高氯酸消解样品,电感耦合等离子体质谱法(ICP-MS)测定苦荞茶中铜、铅、镉、钴、镍的方法.方法具有灵敏度高、检出限低、精密度好、基体干扰少、准确可靠、快捷、简便的特点.各元素方法检出限(3SD,μg/L)分别为:铜0.009、铅0.023、镉0.015、钴0.022、镍0.035;方法精密度(RSD,n=12)分别为:铜2.5%～3.0%、铅2.1%～2.3%、镉3.0%～3.8%、钴2.5%～2.6%、镍1.5%～1.9%;各元素加标回收率分别为:铜95.0%～105.0%、铅95.0%～105.0%、镉98.0%～105.0%、钴95.0%～105.0%、镍95.0%～105.0%.在线用铑作为内标95.0%～105.0%.方法经国家一级标准物质验证,测定值与标准值吻合.应用于实际样品测定,结果满意.     

Dibenzomethanopentacene-Based Polymers of Intrinsic Microporosity for Use in Gas-Separation Membranes

Dibenzomethanopentacene (DBMP) is shown to be a useful structural component for making Polymers of Intrinsic Microporosity (PIMs) with promise for making efficient membranes for gas separations. DBMP-based monomers for PIMs are readily prepared using a Diels–Alder reaction between 2,3-dimethoxyanthracene and norbornadiene as the key synthetic step. Compared to date for the archetypal PIM-1, the incorporation of DBMP simultaneously enhances both gas permeability and the ideal selectivity for one gas over another. Hence, both ideal and mixed gas permeability data for DBMP-rich co-polymers and an amidoxime modified PIM are close to the current Robeson upper bounds, which define the state-of-the-art for the trade-off between permeability and selectivity, for several important gas pairs. Furthermore, long-term studies (over ≈3 years) reveal that the reduction in gas permeabilities on ageing is less for DBMP-containing PIMs relative to that for other high performing PIMs, which is an attractive property for the fabrication of membranes for efficient gas separations.     

液态水热容的量子校正

在不同温度下对液态水进行分子动力学模拟，研究各温度下液态水中各个原子的速度自相关函数密度谱，以考察液态水热容的量子校正随温度的变化规律．研究结果表明，水分子的三个内部振动模式对热容的量子校正不随温度变化，而转动和分子距平衡位置的摆动运动模式的量子校正随温度升高而逐步减小．对于分子动力学模拟结果经温度涨落计算所得的热容进行了量子校正，校正结果与实验值能符合．     

Overview of Special Session B—Compositional and Structural Analysis of Biomass

Special Session B at the 29th Symposium on Biotechnology for Fuels and Chemicals was the first invited session at this symposium devoted to analytical methods. The special topic was added in response to numerous requests for information on new and innovative methods that could be applied in the growing renewable fuels industry. Presentation topics include analytical methods for the characterization and analysis of maize traits, tools for investigating cell wall limitations to enzymatic degradation, methods for customizing enzyme cocktails for biomass, new techniques for the analysis of carbohydrates, analytical methods that enhance our understanding of pretreatment, improved methods for monitoring process intermediates, and published standard analytical methods for biomass conversion processes.     

傅里叶变换近红外光谱法同时定量分析水溶液中乙醇、果糖和葡萄糖

利用乙醇、果糖和葡萄糖在波数为14000-7500cm^-1范围内的吸收值,在近红外谱区用偏最小二乘法（PLS）对体系进行建模,并通过内部和外部样品校验确认最佳数据预处理方法。结果表明,乙醇在0.05-0.25L/L,果糖在0.01-0.05g/mL及葡萄糖在0.005-0.009g/mL的范围内外部校验模型较好的分别是在PLS中所用的一阶偏导（平滑点数是5）、二阶偏导（平滑点数是5）和直线消除法的数据预处理方法所建立的模型,其外部校验预测结果的相对误差在2%左右。此方法具有可同时测定不同样品,简便快速及成本低等优点。     

Normal Coordinate Analysis for Polymer Systems: Capabilities and New Opportunities

Normal coordinate analysis is an important tool in studying the structure, dynamics, and physical properties of polymer systems. In this article the capabilities of normal coordinate analysis (NCA) are explored in some detail. The use of the eigenvalues and eigenvectors from NCA is catalogued for a wide variety of purposes: for assigning or interpreting polymer spectra, for structural determination, for constructing force fields, for computing heat capacity and other thermodynamic properties, and for computing other physical properties. Examples are given for crystals, melts, and amorphous systems. Also described are methods for characterizing the normal mode vectors that are especially useful for larger systems, in which a large amount of data must be analyzed or where visualization or animation fails. Finally, a recently developed method for eliminating negative eigenvalues in systems with tens of thousands of atoms, trajectory averaging, is presented. Also described are several advances in numerical linear algebra for speeding up the diagonalization phase and for computing physical properties without requiring full diagonalization of the Hessian matrix.     

Simultaneous determination of fluoroquinolones,sulfonamides and tetracyclines in sewage sludge by pressurized liquid extraction and liquid chromatography electrospray ionization-mass spectrometry

A new scheme for the quantitative determination of traces of fluoroquinolones (FQs), tetracyclines (TCs) and sulfonamides (SAs) in sewage sludge was developed. The compounds were simultaneously extracted from sewage sludge by pressurized liquid extraction (PLE). A novel and effective method for PLE was developed. Solid-phase extraction was used for cleaning up the extracts. Identification and quantification of the compounds was done using high-performance liquid chromatography with electrospray ionization mass spectrometry in selected reaction monitoring mode. The best recovery of FQs and TCs was obtained by using hydrophilic–lipophilic balance cartridges, recoveries ranged 59% for norfloxacin to 82% for ofloxacin and 95% for doxycycline; for SAs strong cation-exchange cartridges were more efficient, recoveries were 96% for sulfamethoxazole and 43% for sulfadimethoxine. Limit of quantification ranged from 0.1 ng/g for SAs to 160 ng/g for tetracycline. Method precision for TCs was 5.06% and 1.12%, and for SAs 0.43% and 2.01%. FQs precision ranged from 0.77% to 1.89%.     

Treatment of Anomalous Vapor Diffusion in Polymers

The mechanics of thermally-activated gaseous diffusion in polymers have long been studied for development of theoretical understanding of the interactive forces responsible for the non-linear nature of diffusion and the resultant enthalpic changes in the polymer. Methodologies and calculations have been developed in this work for treatment of experimental data for elimination of thickness-related anomalies in water vapor diffusion and for delineation of pressure effects. Linearized data for different polymer thicknesses and the attendant internal thermal effects have been generated by using calculated single molecule diffusion values. Equally linear data are obtained for different pressures by the use of a graphical method from which identical diffusion values are obtained, independent of material thickness and external pressure. True comparisons and classification of polymers as to their diffusivities are thus possible for development of barrier materials for food and drug packaging and for protective encapsulation of electronic devices. Results will be reported for three structurally different polymers. This revised version was published online in July 2006 with corrections to the Cover Date.     

Analysis of urinary biomarkers for exposure to alkyl benzenes by isotope dilution gas chromatography-mass spectrometry

A validated GC-MS method for the analysis of urinary metabolites of alkyl benzenes is reported. Metabolites for exposure to toluene, xylene and ethylbenzene were analyzed simultaneously using stable isotope substituted internal standards. The method entailed acidic deconjugation of urine samples followed by extractive alkylation with pentafluorobenzyl bromide as alkylating agent. The resulting pentafluorobenzyl derivatives of ortho-, meta-, para-cresol, mandelic acid (MA), hippuric acid (HA) and ortho-, meta-, para-methylhippuric acid (MHA) were then quantified by SIM. Optimized reaction conditions for the extractive alkylation step are reported. The derivatives were found to be sufficiently stable for overnight batch analysis. The LODs were below 0.1 micromol/L for the cresols and below 1 micromol/L for MA and the HAs. Within-batch precision for o-MHA was 7%, for m-MHA 5%, for p-MHA 5.2% and below 5% for the rest of the analytes.     

仪器分析标准物质

简述仪器分析标准物质的重要性及我国发展现状，指出了仪器分析标准物质研制中存在的问题。以光谱分析标准物质为例，介绍了仪器分析标准物质研制的特点，光谱分析标准物质的均匀性是研制的关键，其标准不确定度应由定值分析产生的标准不确定度、块状样品间的不均匀性产生的标准不确定度及块状样品内部的不均匀性产生的标准不确定度组成。