Three New Diterpenoids from Isodon nervosus

Three new ent‐kaurane diterpenoids, rabdonervosins D–F ( 1 – 3 ), were isolated from the leaves and stems of Isodon nervosus. Their structures were elucidated on the basis of spectroscopic methods including 1D‐ and 2D‐NMR analyses. Compounds 1 – 3 were evaluated for their cytotoxicity against HepG2, CNE2, PC‐9/ZD, HeLa, MCF‐7, and HCT116 cell lines. No compounds exhibited potent cytotoxicity.     

Separation of polyphenols using porous polyamide resin and assessment of mechanism of retention

A porous polyamide resin is shown to possess hydrogen bond acceptor properties suitable for the separation of polyphenolic solutes such as phenolic acids, flavonols and flavonoids. The separation is achieved in the presence of solvent mixtures of acetic acid and ethanol. The extent of hydrogen bond adsorption is reviewed based on data obtained from the elution behaviour of a variety of simple polyphenolic solutes. Polyamide adsorption chromatography was applied for the purification of resveratrol and polydatin from Polygonum cuspidatum Sieb. & Zucc.     

Surface analysis of high performance carbon/bismaleimide composites exposed to electron irradiation

The aim of this article was to investigate the effects of electron irradiation in ultrahigh vacuum environment on the surface properties of high‐performance carbon/bismaleimide (BMI) composites used in aerospace. The changes in surface chemical composition with increasing irradiation fluence were studied by XPS. The evolution of surface morphology and surface roughness were observed by atomic force microscopy (AFM). The mass loss behavior occurring in the surface layer of the composites was examined. The results indicated that the electron irradiation in high vacuum caused rupture of chemical bonds and cross‐linking process in the surface layer, thereby leading to the mass loss behavior and the formation of carbonification layer in the surface of the carbon/BMI composites. The changes in the surface chemical composition were determined by a competing effect existing between the rupture of chemical bonds and the cross‐linking process at lower irradiation fluence, and by a degradation process only at higher fluence of electron irradiation. The surface morphology was altered and the surface roughness was increased significantly after electron irradiation. The mass loss ratio first increased obviously at lower fluences, and then reached a plateau value of 0.45% beyond 5 × 10¹⁵ cm^?2 fluence of electron irradiation. Copyright © 2011 John Wiley & Sons, Ltd.     

Preparation, characterization, and application of multistimuli-responsive microspheres with fluorescence-labeled magnetic cores and thermoresponsive shells

Novel functional microspheres with multistimuli-responsive properties have been prepared and characterized. The as-prepared microspheres respond to an external magnetic field, environmental temperature, and ultraviolet radiation. The in vitro drug-loading efficiency and drug-release behavior of these microspheres demonstrated that they could be used as drug carriers for drug controlled release. The results of in vivo distribution investigations of these microspheres showed that they exhibit a high magnetic-targeting effect, which holds promise for applications in various fields such as magnetic drug targeting and tissue labeling, among others.     

Recent developments and applications of hybrid surface plasmon resonance interfaces in optical sensing

Nanostructured noble metals exhibit an intense optical near field due to surface plasmon resonance, therefore promising widespread applications and being of interest to a broad spectrum of scientists, ranging from physicists, chemists, and materials scientists to biologists. A wealth of research is available discussing the synthesis, characterization, and application of noble metal nanoparticles in optical sensing. However, with respect to the sensitivity of the frequency and width of these surface plasmon resonance modes to the particle’s shape, size, and environment, in nearly every case, success strongly depends on the availability of highly stable, adhesive, and sensitive nanoparticles. This undoubtedly presents a challenging task to nanofabrication. The past decade has witnessed fascinating advances in this field, in particular, the construction of oxide-based hybrid plasmonic interfaces to overcome the problem addressed above by (1) coating the metallic nanostructures with thin overlayers to form sandwiched structures or (2) embedding metallic nanostructures in a dielectric matrix to obtain metal/dielectric matrix nanocomposite films. In this critical review, we focus on recent work related to this field, beginning with a presentation of hybrid films with enhanced structural and optical stability, readily and selectively designed using chemical and physical techniques. We then illustrate their interesting optical properties and demonstrate exciting evidence for the postulated application in surface plasmon sensing fields. Finally, we survey the work remaining to be done for that potential to be realized.     

溶剂/流速双梯度-HPLC整体柱分析三七中药配方颗粒中4种皂苷成分

建立一种新的溶剂/流速双梯度-整体柱高效液相色谱法快速测定三七中药配方颗粒中4种皂苷成分. 通过乙腈浓度、流速与被测物的lg k线性相关性, 预测被测组分三七皂苷R₁, 人参皂苷Rg₁与人参皂苷Re的适宜k值, 以测得的分离度为优化指标, 建立分离R₁, Rg₁, Re的最佳分离模式1和2|在此基础上, 通过考察乙腈浓度和流速随时间的变化率对分离人参皂苷Rb₁的影响, 以Rb₁与相邻杂质的分离度为优化指标, 得到分离R₁, Rg₁, Re, Rb₁的两种最佳模式. 应用色谱优化函数(COF)作为综合指标评价, 结果显示模式2优化效果更好. 采用模式2的色谱条件, 20 min内完成对三七配方颗粒中4种皂苷成分的质量分析, 结果表明该方法准确可行、快速.     

新型2-氨基-呋喃并[2,3-d]嘧啶-4(3H)-酮衍生物的合成及抗肿瘤活性

报道应用aza-Wittig反应,采用易得的原料,在温和的条件下,以78%～90%的产率有效的合成了新型2-氨基-呋喃并[3,2-d]嘧啶-4(3H)-酮衍生物5,其结构经IR,1H NMR,MS和元素分析确认.为进一步得到结构确认,化合物5c经X射线衍射分析证实.运用噻唑蓝(MTT)标准法对化合物5进行了体外抗肿瘤活性的测定,其中5f对肺癌细胞A459的IC50值为18.4μmol/L,显示出潜在良好的抗肿瘤活性.     

纳米材料电化学与生物传感器——有机微污染物检测新途径

本文介绍了近年来纳米材料电化学与生物传感器在有机微污染物检测中的研究现状,分析了这些传感器中纳米材料修饰电极的特点,重点阐述了纳米材料在有机微污染物检测中的重要作用,列举了一些纳米材料电化学与生物传感器在有机微污染物检测中的应用。最后对纳米材料电化学与生物传感器用于有机微污染物的检测研究进行了简要评述和展望。