季戊四醇衍生物为骨架的糖簇、糖树枝状分子的合成与应用

综述了以季戊四醇衍生物为骨架的糖簇、糖树枝状分子的合成与应用. 由于季戊四醇衍生物本身所具备的结构特点, 这类分子非常适合于合成新型的糖簇分子和糖树枝状分子. 同时, 由于季戊四醇衍生物在有机合成领域应用广泛, 很多有机合成方法都可以应用到这类糖缀合物的合成中.     

糖簇分子和糖树状分子的合成进展

糖簇分子和糖树状分子是为了模拟天然存在的“多价效应”而发展起来的一类糖缀合物 .从糖簇分子和糖树状分子的骨架结构特点出发 ,综述了近几年来多价糖簇分子和糖树状分子的各种合成方法及其特点     

多价半乳糖配体的设计及其对肝去唾液酸糖蛋白受体结合的研究

In an effort to find highly efficient ligands for hepatic asialoglycoprotein receptor(ASGPR),four cluster galac-tosides with different scaffolds were synthesized in this paper.The affinity of these compounds for ASGPR wasanalyzed by binding study in vitro.The results showed that trivalent cluster galactosides behaved better than diva-lent analogues and the cluster galactosides with aryl groups on their scaffolds presented better binding affinity thanthose with aliphatic chain scaffolds.     

二、三分枝甘露糖簇衍生物的合成

采取一种有效途径合成了二、三分支的甘露糖簇分子．甘露糖经烯丙苷化、乙 酰基保护后，将其烯丙基的双键氧化得到带有羧基连接臂的甘露糖衍生物，然后再 分别与l，6-己二胺和三(2-氨乙基)胺进行缩合反应，最后脱掉保护基，得到二分 枝甘露糖簇化合物6和三分枝甘露糖簇化合物8．     

One-pot Synthesis of Divalent and Trivalent Cluster Mannosides via Ugi Four-component Reaction

The Ugi four-component reaction (U-4CR) was utilized to prepare divalent and trivalent cluster mannosides. Thus, two target compounds 6 and 8 were obtained efficiently using carboxymethyl 2, 3, 4, 6-tetra-O-acety-α-D-mannopyranoside 4 as acid component, and 1, 6-hexanediamine or tris(2-aminoethyl)amine as the multivalent scaffolds.     

Synthesis of Oligomeric Mannosides and Their Structure‐Binding Relationship with Concanavalin A

Small glycodendrimers with α‐mannosyl ligands were synthesized by using copper‐catalyzed azide–alkyne coupling chemistry and some of these molecules were used as multivalent ligands to study the induction of concanavalin A (Con A) precipitation. The results showed that the monovalent mannose ligand could induce the precipitation of Con A. This unexpected finding initiated a series of studies to characterize the molecular basis of the ligand–lectin interaction. The atypical precipitation is found to be specific to the mannose, fluorescein moiety (FITC), and Con A. Apparently the mannose ligand binds to Con A through hydrogen‐bonding interactions, whereas the binding of FITC is mediated by hydrophobic forces.     

糖簇分子和糖树状分子及其生物学活性

糖簇分子和糖树状分子是近年来发展起来的一类新型糖缀合物,其目的是模拟天然存在的“多元效应”。本文主要综述了目前已知糖簇分子和糖树状分子所具有的生物活性及其潜在的应用领域。     

弱酸介质中类球形谷氨酸/镁铝层状双氢氧化物的制备

在弱酸性介质中,采用阴离子交换法合成了类球形的谷氨酸(Glu)/镁铝层状双氢氧化物(MgAl-LDH)复合物,研究了介质pH值对所得Glu/LDH纳米复合物性质和形貌的影响。结果表明,与碱性介质中阴离子交换法得到的不规则六角形粒子相比,该法制备的纳米粒子呈类球形,且粒径较小,最佳pH值为5.0,探讨了可能的反应机理。     

The Synthesis and Anion Binding of Novel Cholic Acid-based Molecular Clefts Containing Unsymmetrically Disubstituted Urea Unit

A novel type of chiral molecular clefts consisting of a rigid deoxycholic acid methyl ester backbone and chiral unsymmetrically disubstituted urea side chain have been designed and synthesized. All these new receptors 3a-c and the corresponding key intermediates la-c and 2a-c are new compounds, their structures were confirmed by ^1HNMR, IR, MS spectra and elemental analysis. These molecular clefts showed binding ability for halide anions.     

Application of a Glassy Carbon Electrode Modified with Poly(Glutamic Acid) in Caffeic Acid Determination

Glassy carbon electrodes were coated with films of poly(glutamic acid) (PG), and the modified electrode proved to be very effective in the oxidation of caffeic acid. The performance of the film was also tested with ascorbic acid, coumaric acid, ferulic acid, sinapic acid and chlorogenic acid. At pH 5.6, all the hydroxycinnamic acids yield a higher peak current intensity when oxidized after incorporation in the PG-modified electrode, and only the oxidation of ascorbic acid exhibits overpotential reduction. At pH 3.5 only caffeic and chlorogenic acid are incorporated in the modified electrode and exhibit a well-defined oxidation wave at +0.51 V and +0.48 V, which is the base for their determination. Linear calibration graphs were obtained from 9 × 10⁻⁶ mol L⁻¹ to 4 × 10⁻⁵ mol L⁻¹ caffeic acid by linear voltammetric scan and from 4 × 10⁻⁶ mol L⁻¹ to 3 × 10⁻⁵ mol L⁻¹ by square wave voltammetric scan. The method was successfully applied to the determination of caffeic acid in red wine samples without interference from other hydroxycinnamic acids or ascorbic acid.     

Synthesis of Polymer-Supported Heteronuclear Rhodium- Cobalt Bimetallic Carbonyl Cluster Catalysts and Their Hydroformylation Properties

Tetranuclear Rh-Co bimetallic cluster was synthesized and characterized by IR and XPS. The properties of the anchored catalysts, its stability and the ligand effect were also studied. The experimental results show that the optimal conditions for the hydroformylation of hexene-1 are as follows: the temperature is 80℃, reaction time 8 h, pressure 5. 88×105 Pa, and molar ratio of H2/CO 1. 2/1. 0. Functional groups attached to the donor atom(N) possess more or less some influence on the catalytic behavior. Compared with the homogeneous cluster, the polymer-supported bimetallic cluster is more stable. After the catalytic reaction, the structure of the anchored catalysts was not destroyed. X-ray photoelectron spectroscopy characterization indicates that there is a weak interaction between the polymer support and the active metals.     

Validation of HPLC Method for Analysis of Gamma-Aminobutyric and Glutamic Acids in Plant Foods and Medicinal Plants

Gamma-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the central nervous system of mammals and plays an important role in the suppression of neurons’ excitability. GABA is formed from the decarboxylation of glutamic acid (Glu), and both GABA and Glu could be considered as important biologically active food components. In the current study, we validated a HPLC method for concomitant detection of GABA and Glu in plant samples after derivatization with dansyl chloride. The validated method had high precision and a high recovery rate and was successfully used for GABA and Glu quantification in 55 plant foods (fruits, vegetables, legumes, cereals, pseudocereals, and nuts) and 19 medicinal plants. Vegetables were the most important dietary source of these amino acids, with the highest quantity of GABA found in potatoes—44.86 mg/100 g fresh weight (FW) and yellow cherry tomatoes—36.82 mg/100 g FW. The highest amount of Glu (53.58 mg/100 g FW) was found in red cherry tomatoes. Analyzed fruits were relatively poor in GABA and Glu, and European gooseberry was the richest fruit with 13.18 mg/100 g FW GABA and 10.95 mg/100 g FW Glu. Cereals, pseudocereals, nuts, and legumes contain much higher amounts of Glu than GABA. The obtained results enrich the available information on the content of gamma-aminobutyric and glutamic acids in plant foods and could be used for the development of GABA-enriched functional foods.     

一氧化氮在水杨醛谷氨酸合镍修饰碳黑微电极上的电催化氧化

制备了水杨醛谷氨酸合镍修饰碳黑微电极,试验了修饰电极对一氧化氮的电催化氧化性能。试验结果表明,在pH 6.8的磷酸盐中,一氧化氮在该电极上的线性范围为4.0×10-8~1.0×10-5mol.L-1;检出限(3σ)为1.0×10-8mol.L-1。将此电极用于3种模拟样品的分析,并在此基础作回收率试验,测得RSD(n=8)值在1.9%~2.8%之间,回收率在97%~105%之间。在一氧化氮浓度1.0×10-6mol.L-1的水平上进行精密度试验,测得RSD(n=10)为2.2%。     

Synthesis and Crystal Structure of a Hexameric Organooxotin Cluster from Benzilic Acid

1 INTRODUCTION There is great interest in the study of organotin carboxylic ester compounds due to their consider- able biological activities and structural diversities[1~3]. Since Holmes, R. R.[4] first reported the hexameric drum organotin compound, many organotin carboxy- lic ester compounds with drum-shape have been syn- thesized in recent years[5, 6]. It has been revealed that organotin compounds containing carboxylate ligands with additional donor atoms that are available for coord…     

马来松香酸基酰胺化合物的合成及除草活性

以马来松香酸为原料,经酰氯化和与苯胺类化合物的N-酰化反应后,得到9个新颖的马来松香酸基酰胺类化合物,其结构均经1H NMR、13C NMR、IR和元素分析确证。初步的除草活性测试表明,在浓度为100μg/mL时,目标产物对油菜的胚根生长有一定抑制作用,其中化合物3c(R=4-ClC6H4)的活性最好,抑制率为66.1%。     

Preconcentration of Rutin at a Poly Glutamic Acid Modified Electrode and its Determination by Square Wave Voltammetry

Abstract

The voltammetric determination of rutin in 0.04 mol l^?1 B‐R buffer (pH 4.0) by square wave voltammograms (+0.41 V vs. Ag/AgCl_(sat.)) at a poly glutamic acid modified glassy carbon electrode was found to be several orders of magnitude lower than that on a bare glassy carbon electrode. Rutin can be preconcentrated on the films of poly glutamic acid and presented linear relationship from concentration of 7×10^?7 to 1×10^?5 mol l^?1 in 0.04 mol l^?1 B‐R buffer pH 4.0. The method was successfully applied to the determination of rutin in pharmaceutical formulation without any pretreatment.     

新型丙烯海松酸基双噻二唑化合物的合成及其抗真菌活性

松香与丙烯酸经Diels-Alder环加成反应制得丙烯海松酸(1); 将1转化为双酰氯后与2-氨基-5-取代苯基-1,3,4-噻二唑经-N-酰化反应合成了8个新型的丙烯海松酸基双噻二唑化合物(4a~4h),其结构经¹H NMR, ¹³C NMR, IR和元素分析表征。抗真菌活性测试结果表明,在用药量为50 μg·mL^-1时,4d(R=m-Cl)对苹果轮纹病菌、花生褐斑病菌和小麦赤霉病菌的抑制率分别为66.9%, 57.8%和52.9%。     

Analysis of Glutamic Acid in Cerebrospinal Fluid by Capillary Electrophoresis with High Frequency Conductivity Detection

Glutamic acid(Glu)is the most important amino acid in the nerve center system1.It isessential to detect Glu in cerebrospinal fluids(CSF),because the level of Glu in CSF hasimplicated several diseases such as metabolic diseases or central nervous systemdisorders2.The measurement of Glu in CSF had been performed by high performanceliquid chromatography(HPLC)and capillary electrophoresis(CE)with inducedfluorescence detection3-7.Since Glu shows no fluorescence,different reagents had beenus…     

18β-甘草次酸A环官能团化衍生物的合成及抗肿瘤活性

采用化学方法对18β-甘草次酸A环进行改造, 合成了一系列新型18β-甘草次酸A环官能团化衍生物. 对人白血病细胞株HL-60、K562、肝癌细胞BEL-7404及乳腺癌细胞MDA-MB-231的体外抗肿瘤活性筛选结果表明, 化合物5对4种肿瘤细胞系的抑制活性均强于18β-甘草次酸; 构效关系分析表明, A环内烯键的形成对抑制肿瘤细胞增殖有重要影响; 同时利用Hoechst33258和AO/EB染色, 在荧光显微镜下观察到了细胞凋亡小体的形成.     

Synthesis and Properties of Lactic Acid-based Cross-linked Poly（ester-amide）

Polylactide (PLA), made from agriculture products, was one of biodegradable polymers1,2. Owing to its characters, PLA and its copolymers have received great interest in industrial and medical applications3-6, such as drug delivery systems, sutures, artifi…