Three new compounds from Sarcandra glabra

One new sesquiterpene lactone,1 α,8 α,9 α-trihydroxyeudesman-3(4),7(11)-dien-8 β,12-olide(1) and two new phenylpropanoidsubstituted catechin glycosides,glabraoside C(2) and glabraoside D(3) were isolated from the whole plant of Sarcandra glabra. Their structures were established by the analyses of spectral and chemical evidences.     

关于广义三项指数和的四次幂均值

The main purpose of this paper is using estimates for trigonometric sums and properties of congruence to study the computation of one kind of fourth power mean of a generalized three-term exponential sum, and give an interesting identity for it.     

双模板介导合成类骨磷灰石的研究进展

天然骨形成是一个多模板协同共组装的过程。与单模板自组装相比,双模板介导合成的类骨磷灰石具有与天然骨更加相近的多级结构,在生物矿化研究领域具有更重要的研究意义。本文介绍了双模板介导合成类骨磷灰石的研究进展,探讨了双模板的选择、设计及模板分子间的相互作用,阐述了模板对磷灰石晶体成核的调控机制。通过双模板介导自组装生成的磷灰石材料,以其特有的仿生多级结构和骨诱导效果,在骨缺损修复、齿科修复、表面涂层及药物载体等领域具有广阔的应用前景。     

CP@NiAl-LDH复合材料的制备及其超级电容器性能

通过采用简易温和的水热条件制备导电聚合物@镍铝层状双金属氧化物复合材料（CP@NiAl-LDH）,构建电子/离子的高速传输纳米通道,利用SEM和XRD对复合材料结构形貌进行表征。电化学性能测试结果表明,导电聚合物为复合材料提供一定的赝电容,促进电荷的快速转移,使CP@NiAl-LDH的电容性能得以显著提升。PPy@LDH具有最好的电容性能,在1 A·g^-1的电流密度下,其比容量高达3 010.3 F·g^-1,当电流密度升高到20 A·g^-1时,其比电容保持率为73.1%,表现出优异的倍率性能;同时,在10 A·g^-1的电流密度下10 000次充放电循环后仍具有88.8%的比容量保持率,具有优异的循环稳定性。这主要归功于NiAl-LDH与导电聚合物之间的协同增强效应。     

氢化物发生-原子荧光光谱法同时测定水中砷和锑

建立在硝酸介质中用氢化物发生-原子荧光光谱法同时测定水中砷和锑的方法。优化了仪器工作条件、酸度、硼氢化钾及还原剂浓度。砷、锑的线性范围为0～10．0μg／L;检出限分别为0．02,0．01μg／L;测定结果的相对标准偏差分别为1．77％～3．72％,2．95％～4．87％（n=6）;加标回收率分别为98％106％,96％105％。该法操作简便,灵敏度高,快速,便于推广,适用于水中砷和锑的同时测定。     

Quasi-classical Trajectory Study of F-I-H20→HF-I-OH Reaction： Influence of Barrier Height,Reactant Rotational Excitation,and Isotopic Substitution

The reaction dynamics of the F＋H20/D20→HF/DF＋OH/OD are investigated on an accurate potential energy surface （PES） using a quasi-classical trajectory method. For both isotopomers, the hydrogen/deuterium abstraction reaction is dominated by a direct rebound mechanism over a very low ＂reactant-like＂ barrier, which leads to a vibrationally hot HF/DF product with an internally cold OH/OD companion. It is shown that the lowered reaction barrier on this PES, as suggested by high-level ab initio calculations, leads to a much better agreement with the experimental reaction cross section, but has little impact on the product state distributions and mode selectivity. Our results further indicate that rotational excitation of the H20 reactant leads to significant enhancement of the reactivity, suggesting a strong coupling with the reaction coordinate.     

In-situ interaction of nano-PbS with gelatin

Water-soluble gelatin–PbS bionanocomposites(BNCs)were synthesized via a facile one-pot chemical reaction method at pH7.40.The samples were characterized by transmission electron microscopy(TEM),X-ray diffraction(XRD),UV-vis absorption spectra(UV-vis),Fourier transform infrared spectra(FT-IR)and circular dichroism(CD).FT-IR data were used to envisage the binding of PbS particles with oxygen atoms of carbonyl groups of gelatin molecule.The possible integration mechanism between gelatin and PbS was discussed in detail.The effect of Pb2+and PbS on the conformations of gelatin has also been analyzed by means of UV-vis,CD and FT-IR spectra,resulting in less-helix content and more open structures(-sheet,β-turn,or expanded).A new formula to calculate the association constant was proposed according to the relationship between the absorbance of gelatin–PbS BNCs and the free concentration of PbS,and apparent association constants K(298/303/308 K:3.11/2.00/1.60×106mol/L)at three different temperatures were calculated based on this formula.Thermodynamic parameters such asΔGθ,ΔHθ andΔSθ were also determined.The results of the thermodynamic investigations indicated that the reaction was spontaneous(ΔGθ<0),and enthalpy-driven(ΔHθ<0).     

Fluorescent AIE dots encapsulated organically modified silica (ORMOSIL) nanoparticles for two-photon cellular imaging

2,3-Bis(4-(phenyl(4-(1,2,2-triphenylvinyl)phenyl)amino)phenyl) fumaronitrile (TPE-TPA-FN or TTF), which possesses aggregation-induced emission (AIE) characteristic, is doped in organically modified silica (ORMOSIL) nanoparticles. By increasing the weight ratio of TTF to the precursor of silica nanoparticles (the quantities of the precursors were kept the same), the fluorescence intensity of nanoparticles increased correspondingly, due to the formation of larger AIE dots in the cores of ORMOSIL nanoparticles. The fluorescent and biocompatible nanoprobes were then utilized for in vitro imaging of HeLa cells. Two-photon fluorescence microscopy clearly illustrated that the nanoparticles have the capacity of nucleus permeability, as well as cytoplasm staining towards tumor cells. Our experimental results may offer a promising method for fast and bright fluorescence imaging, as well as bio-molecule/drug delivery to cell nucleus.     

Chemomics and drug innovation

Chemomics is an interdisciplinary study using approaches from chemoinformatics,bioinformatics,synthetic chemistry,and other related disciplines.Biological systems make natural products from endogenous small molecules (natural product building blocks) through a sequence of enzyme catalytic reactions.For each reaction,the natural product building blocks may contribute a group of atoms to the target natural product.We describe this group of atoms as a chemoyl.A chemome is the complete set of chemoyls in an organism.Chemomics studies chemomes and the principles of natural product syntheses and evolutions.Driven by survival and reproductive demands,biological systems have developed effective protocols to synthesize natural products in order to respond to environmental changes;this results in biological and chemical diversity.In recent years,it has been realized that one of the bottlenecks in drug discovery is the lack of chemical resources for drug screening.Chemomics may solve this problem by revealing the rules governing the creation of chemical diversity in biological systems,and by developing biomimetic synthesis approaches to make quasi natural product libraries for drug screening.This treatise introduces chemomics and outlines its contents and potential applications in the fields of drug innovation.     

Preface

In life sciences,molecules are categorized into biological macromolecules(protein,DNA,RNA etc.)and small molecules(neurotransmitters,vitamins,drugs,natural products,water etc.).The main methodology of chemistry for life sciences is using chemical techniques and tools to explore and manipulate the functions of biological macromolecules.This methodology can be traced back to W hler’s synthesis of urea from"inorganic"compounds in 1828.Today,we realize that chemistry can advance a molecular understanding of biology,and the harnessing of biology can advance chemical knowledge as well[1–4].Chemicals are widely used as probes to investigate biological functions[5–7].