Three New Anthraquinones from Polygonum cillinerve

Three new anthraquinones, emodin-8-β-D-（2＂-O-coumarate）glucoside 1, emodin-8-β-D-（6＇-O-acetyl）glucoside 2 and physicon-8-β-D-（6＇-O-acetyl）glucoside 3, were isolated from the roots of Polygonum cillinerve and their structures were established by spectroscopic methods. The biological activity indicated that compound 1 had the scavenging activity on 1,1-diphenyl-2-picrylhydrazyl （DPPH） radicals （the IC50 = 8.5 μmol/L）, and compound 1-3 showed no activities against HL-60 and BCJC-823 cells by MTT method in vitro.     

Synthesis and Characterization of Novel Polyimides Based on Pyridine-containing Diamine

A new aromatic diamine monomer containing pyridine unit, 2,6-bis （4-aminophenoxy- 4＇-benzoyl）pyridine（BABP）, was synthesized in three steps, starting from 2,6-pyridinedicarboxyl chloride. A series of novel pyridine-containing polyimides were prepared v/a the polycondensation of BABP with various aromatic dianhydrides through poly（amic acid） precursors, and thermal or chemical imidization of the precursors. The polyimides exhibit desirable properties, e.g., good solubility in N-methyl-2-pyrrolidone and m-cresol, excellent thermal stability and film-forming capability, as well as high inherent viscosity, indicating high molecular weight.     

Cu（I）/Diamine-catalyzed Aryl-alkyne Coupling Reactions

Arylalkynes are important building blocks for the synthesis of natural products,pharmaceuticals,and artificial molecular devices1.They are often synthesized via the Pd-catalyzed Sonogashira coupling reactions between aryl halides and terminal alkynes2,3.Unfortunately,it remains difficult to apply the Sonogashira reaction to industrial scale and/or pharmaceutical synthesis,due to the high cost of Pd and the difficulty in removing the toxic Pd residues from the reaction products.Thus it is wor…     

新显色剂1-(6-羟基-2-嘌呤基)-3-[4-(苯基偶氮)苯基]-三氮烯的合成及与镉的显色反应

合成了新显色剂1 (6 羟基 2 嘌呤基) 3 [4 (苯基偶氮)苯基] 三氮烯(简称HPAPT),研究了它的性质及其与镉显色反应的条件。实验表明,试剂的分子式为C17H13N9,相对分子质量为359,熔点127～129℃,各级酸离解常数为pKa1=4.1,pKa2=7.2,pKa3=10 7。在pH9.0～11.0的Na2B4O7 NaOH缓冲介质中,试剂与镉形成2∶1的红色络合物,表观摩尔吸光系数为2 25×105L·mol-1·cm-1,镉质量浓度在0～0.6mg/L范围内符合比耳定律,在联合掩蔽剂的作用下,可不经分离直接测定环境水样和工业废水中微量镉。     

选相原位法合成立方氮化硼的关键影响因素

利用选相原位法在水溶液中成功制备出了立方氮化硼晶体，对反应条件进行了优化。结果表明，利用选相原位法合成立方氮化硼的最佳实验条件是：反应压力为10.0 MPa，在氯离子加入下利用混合氮源进行反应。在该条件下得到了纯相的立方氮化硼晶体。     

Poly(methacrylic acid-ethylene glycol dimethacrylate) monolith in-tube solid-phase microextraction applied to simultaneous analysis of some amphetamine derivatives in urine by capillary zone electrophoresis

A method based on in-tube solid-phase microextraction and capillary zone electrophoresis (CZE) was proposed for simultaneously determining four amphetamines (amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine, and 3,4-methylenedioxymethamphetamine) in urine. A poly(methacrylic acid-ethylene glycol dimethacrylate) monolithic capillary column, which can provide sufficient extraction efficiency, was introduced for the extraction of amphetamines from urine samples. The hydrophobic main chains and acidic pendant groups of the monolithic column make it a superior material for extraction of basic analytes from aqueous matrix. After extraction, the samples were analyzed by CZE. The best separation was achieved using a buffer composed of 0.1 M disodium hydrogen phosphate (adjusted to pH 4.5 with 1 M hydrochloric acid) and 20% methanol v/v, with a temperature and voltage of 25 degrees C and 20 kV, respectively. By applying electrokinetic injection with field-amplified sample stacking, detection limits of 25-34 microg/L were achieved. Excellent method of reproducibility was found over a linear range of 0.1-5 mg/L. Determination of these analytes from abusers' urine sample was also demonstrated.     

An effective skeletal muscle prefractionation method to remove abundant structural proteins for optimized two-dimensional gel electrophoresis

Proteomic analysis of biological samples in disease models or therapeutic intervention studies requires the ability to detect and identify biologically relevant proteins present in relatively low concentrations. The detection and analysis of these low-level proteins is hindered by the presence of a few proteins that are expressed in relatively high concentrations. In the case of muscle tissue, highly abundant structural proteins, such as actin, myosin, and tropomyosin, compromise the detection and analysis of more biologically relevant proteins. We have developed a practical protocol which exploits high-pH extraction to reduce or remove abundant structural proteins from skeletal muscle crude membrane preparations in a manner suitable for two dimensional gel electrophoresis. An initial whole-cell muscle lysate is generated by homogenization of powdered tissue in Tris-base. This lysate is subsequently partitioned into a supernatant and pellet containing the majority of structural proteins. Treatment of the pellet with high-pH conditions effectively releases structural proteins from membrane compartments which are then removed through ultracentrifugation. Mass spectrometric identification shows that the majority of protein spots reduced or removed by high-pH treatment were contractile proteins or contractile-related proteins. Removal of these proteins enabled successful detection and identification of minor proteins. Structural protein removal also results in significant improvement of gel quality and the ability to load higher amounts of total protein for the detection of lower abundant protein classes.     

The design of an on-line semi-preparative LC-SPE-NMR system for trace analysis

This paper reports the design of an on-line semi-preparative LC-SPE-NMR system and its use in the structural analysis of mixture components at the 0.02-1% level. The combination provides at least a five fold mass sensitivity increase over that obtained from typical analytical LC-SPE systems and a >30-fold total NMR sensitivity enhancement over analysis by LC-NMR. This is accomplished by using a novel on-line device to store, dilute (1-100-fold) and deliver (at an optimized flow-rate) the isolated component of interest to an SPE trap unit. The SPE unit consists of two cartridges connected in parallel to increase the overall SPE capacity and also to decrease the flow-rate through each trap for enhanced trapping efficiency. As the coupling of semi-preparative LC with NMR (through SPE) is well matched in terms of optimal mass loading for both techniques, only one LC-SPE cycle is required to enrich a 50 microg ml(-1) component (1% in a 5 mg ml(-1) mixture) for the acquisition of heteronuclear (1)H-(13)C NMR data using a conventional NMR flow probe. Furthermore, analytes at the 0.02% level (approximately 1 microg ml(-1)) can be studied using 2D (1)H NMR techniques if peak cuts from replicate sample injections (> or =3) are accumulated into the storage/dilution unit and the resulting solution processed by just one SPE trap and elute cycle.     

Synthesis of amine-modified mesoporous materials for CO2 capture by a one-pot template-free method

A one-pot template-free route was developed for the synthesis of novel tetraethylenepentamine modified porous silica as CO₂ adsorbents, the obtained materials were characterized by N₂ adsorption/desorption, thermogravimetry, elemental analysis, Fourier transform infrared spectrometry,scanning electron microscopy and transmission electron microscopy. It was found that the amine species were inserted into the silica skeleton, which considerably enhanced their dispersion. Compared with similar materials derived from impregnation, the porous structure of the silica can be better reserved, leading to a promising CO₂ adsorption capacity of 3.98 mmol CO₂/g-adsorbent and a fast adsorption kinetic in simulated flue gas at 348 K. The resulted adsorbents could also be easily regenerated and showed a good durability in multiple adsorption–desorption cycles. All these features make this method a promising option for the preparation of CO₂ adsorbents.     

Bio-inspired fabrication of well-oriented ZnO nanorod arrays film and its superhydrophobicity and superhydrophilicity

A highly oriented ZnO nanorod array film was fabricated on glass substrate by combinations of Sol–Gel and hydrothermal. The film exhibits perfect superhydrophobicity with a contact angle of 155° and a glide angle of 4° after being surface modified by fluoroalkylsilane, which is similar with wings’ property and structures of large yellow spots mosquitoes. Interestingly, the ZnO nanorods film were converted from superhydrophobicity into superhydrophilicity under ultraviolet light for 2 h due to the decomposition of fluoroalkyl chain of fluoroalkylsilane and the photosensitivity of ZnO surface. The transition mechanisms of wettability are discussed on the basis of correlated theories.