Quick estimation of the Dpb for predicting the strength of chemical bond in situ

An approximate method has been established to calculate the depth of the potential acting on an electron in a molecule at the saddle point along a chemical bond, denoted by Dpb. It is a new indicator which can be used for predicting the strength of a chemical bond. In this work, as a practical application for demonstrating thismethod, we calculated the Dpb of deoxyribonucleosides and ribonucleosides along all C-H and N-H chemical bonds using the method. The results are in fair agreement with those results of previously reported experimental and theoretical observations.     

Preparation and study of photoswitchable fluorescence nanoparticles based on spirobenzopyran

The preparation and performance characterization of〈50 nm spirobenzopyran-based photochromic nanocomposites with photoswitchable fluorescence are presented.The nanocomposites were fabricated by means of a modifed miniemulsion polymerization process,in which the hydrophobic spirobenzopyran was covalently attached to the polymer chains and the matched fluorescent dyes were noncovalently embedded in the nanoscale cross-linked polymeric matrix,respectively.The obtained nanocomposites with a high relative fluorescence quantum yield（Q）exhibited superior fluorescent photoswitchable performance due to the effective photo-induced intermolecular energy transfer.The stability of photomerocyanine was also improved.     

One inorganic-organic hybrid derived from reduced molybdophosphate and trinuclear cadmium(Ⅱ) fragment

One new polyoxometalate (POM)-based inorganic-organic hybrid [Cd3Ⅱ(HPO4)(Hbpp)(H2O)2]{CdⅡ[P4- Mo6O28H3.5(OH)3]2} (H4tpb)·7H2O (1) (bpp = 1,3-bis-(4-pyridyl)propane, tpb = 1,2,4,5-tetra(4-pyridyl)-benzene) constructed from reduced molybdophosphate [P4Mo6O28H3.5(OH)3]5.5- (P4Mo6), trinuclear CdⅡ-phosphate-Hbpp fragment and protonated tpb has been hydrothermally synthesized and structurally characterized by IR, elemental analyses and single crystal X-ray diffraction. The complex 1 crystallizes in the monoclinic system with the space group P21/c and cell parameters of a = 15.672(12)Å, b = 23.839(19)Å, c = 27.654(2)Å, β = 115.850(10)8, V = 9297.9(12) Å3, Z = 4, R1 = 0.0534 and wR2 = 0.1135. In complex 1, the P4Mo6 units are bridged by CdⅡ ions to form the classic sandwich-type [Cd(P4Mo6)2] dimers, which are further connected into a two dimensional network via the trinuclear CdⅡ subunits. The tpb is synthesized in situ from the bpp ligands and connects the adjacent 2D layers into a 3D supramolecular framework through hydrogen bonding interactions. The electrochemical and fluorescent properties of complex 1 have been investigated.     

Triazole and Benzotriazole Derivatives as Novel Inhibitors for p90 Ribosomal S6 Protein Kinase 2： Synthesis, Molecular Docking and SAR Analysis

A series of triazole and benzotriazole derivatives as novel p90 ribosomal S6 protein kinase 2 （RSK2） inhibitors were designed and synthesized. The in vitro activities against RSK2 were evaluated, and among 14 compounds, compounds 5, 6, 11, 12, 13 and 14 exhibited enzyme IC50 values of 8.91, 2.86, 3.19, 3.05, 4.49 and 2.09 μmol/L re- spectively. The proposed binding modes were simulated using molecular docking method, and the docking results coupled with the stmcture-activi1：y relationship （SAR） analysis indicated that all these active compounds bound to the RSK2 ATP binding site at NTKD, and the electron-donating groups on the 4-position of phenyl were the deter- minant point for the inhibitory activity.     

含巯基/二硫键聚合物生物材料

含巯基/二硫键聚合物生物材料具有多种良好的性能,作为药物、基因等的释放载体在生物医学领域具有广泛的应用前景。随着基因工程和组织工程的发展,含巯基/二硫键聚合物生物材料的可生物降解性得到高度重视,而怎样改善其降解性能成为限制其应用的关键因素。由于二硫键在细胞外环境里保持稳定,在细胞溶质的还原环境中容易发生断裂,因此在制备新型基因、药物等释放载体上,二硫键充当了重要的角色,它的引入为聚合物生物材料的生物降解性能的设计与改善提供了一条重要的途径。本综述重点以聚合物水凝胶、聚合物微胶束、囊泡等为例,从巯基/烯的光聚合反应、Michael加成反应、氧化还原反应的角度,介绍了巯基/烯在聚合物中形成二硫键的不同途径的研究进展,并详细论述了基因载体、蛋白质载体、小分子药物载体三种还原敏感型材料的制备、表面修饰和改性的进展情况,进一步强调含巯基/二硫键聚合物生物材料的研究在生物医学领域应用的重要性。     

茚三酮衍生高效毛细管电泳法测定纯奶中的甘氨酸含量

建立了茚三酮衍生高效毛细管电泳法测定纯奶中甘氨酸含量的方法,该法可选择性测定甘氨酸含量。使用氯化镁为蛋白沉淀剂,沉淀效果较好,研究了甘氨酸–茚三酮聚合物衍生条件,确定最佳实验条件为:未涂层弹性石英毛细管柱(60 cm×75μm,有效长度49 cm),分离缓冲溶液为3.5 mmol磷酸二氢钾–8.2 mmol磷酸氢二钠(pH 6.8),检测波长为570 nm,电泳电压为25 kV,进样压力为25 kPa,进样时间为3 s,电泳温度为室温。甘氨酸的线性范围为2.00~200.00μg/mL,检出限为0.14μg/mL,线性相关系数不小于0.999。甘氨酸的加标回收率为88.7%~107.2%,测定结果的相对标准偏差为2.9%~4.2%(n=6)。该法简便、快速、准确,可用于测定纯奶中甘氨酸含量。     

超高效液相色谱-串联质谱法鉴别十字花科植物中硫代葡萄糖苷

建立超高效液相色谱–串联质谱法鉴别十字花科植物中硫代葡萄糖苷的分析方法。采用70%甲醇水溶液提取白芥种子中的硫代葡萄糖苷,通过反相C18柱分离,电喷雾–离子阱–飞行时间质谱测定。利用硫代葡萄糖苷二级质谱裂解产生的m/z 195,241,259,275,291特征离子和伴随产生的80,162,163,196,242 Da中性分子丢失规律,共鉴别出5种硫代葡萄糖苷。     

Electrodeposition of PdAu Alloy Nanoparticles on Ionic Liquid Functionalized Graphene Film for the Voltammetric Determination of Oxalic Acid

An ionic liquid functionalized graphene film was prepared and PdAu nanoparticles (NPs) were electrodeposited on it. The PdAu NPs were characterized by various methods and they showed the features of alloys. In 0.2 M H₂SO₄ solution, oxalic acid (OA) exhibited a sensitive anodic peak at the resulting electrode at about 1.1 V (vs. SCE), and the peak current was linear to OA concentration in the range of 5–100 µM with a sensitivity of 45.5 µA/mM. The detection limit was 2.7 µM (S/N=3). The electrode was successfully applied to the determination of OA in real sample.     

具有模拟SOD功能的大分子

生命活动中用于维持生物体内超氧阴离子自由基动态平衡的超氧化物歧化酶(superoxidedismutase,SOD)是一类金属酶,属于典型的生物大分子金属络合物,因其在生命活动中所起的重要作用而备受关注。目前,有关SOD的模拟已从小分子化合物的模拟,走向大分子环境与活性中心相结合的系统模拟。本文从高分子化合物角度对模拟SOD的研究进展作一综述,以期为设计并开发具有生物相容且高活性的新型高分子抗氧化剂提供新思路。天然大分子有蛋白质与多肽、多糖、分子聚集体,目前所采用的蛋白质(多肽)是性能稳定的天然蛋白质或通过基因重组技术生物合成的蛋白质或多肽,所采用的多糖类物质主要有右旋糖酐、羧甲基纤维素、壳聚糖等。小分子活性化合物(如金属卟啉、新型肟类为配体的同核与异核复合物、salen型金属配合物等)通过与这些天然大分子结合,在提高活性的同时也改善了其稳定性。将活性小分子物质与分子聚集体(如胶束、脂质体)结合制得的SOD模拟物可以模拟天然SOD在体内的环境,提高抗氧化活性和体内循环时间。合成高分子模拟SOD的工作主要集中于高分子接枝金属配合物的研究,其中典型的合成高分子有聚乙二醇(polyethylene glycol,PEG)、聚L-赖氨酸、聚(苯乙烯-马来酸酐)、聚(环己烷-1,4-丙酮二亚甲基缩酮)、氯化聚苯乙烯树脂、聚乳酸和一些嵌段共聚物,其抗氧化活性与金属配体有关,是一类潜在的抗癌药物。     

Screening of aromatase inhibitors in traditional Chinese medicines by electrophoretically mediated microanalysis in a partially filled capillary

An electrophoretically mediated microanalysis method with partial filling technique was developed for screening aromatase inhibitors in traditional Chinese medicine. The in‐capillary enzymatic reaction was performed in 20 mM sodium phosphate buffer (pH 7.4), and sodium phosphate buffer (20 mM, pH 8.0) was used as a background electrolyte. A long plug of coenzyme reduced β‐nicotinamide adenine dinucleotide 2′‐phosphate hydrate dissolved in the reaction buffer was hydrodynamically injected into a fused silica capillary followed by the injection of reaction buffer, enzyme, and substrate solution. The reaction was initiated with a voltage of 5 kV applied to the capillary for 40 s. The voltage was turned off for 20 min to increase the product amount and again turned on at a constant voltage of 20 kV to separate all the components. Direct detection was performed at 260 nm. The enzyme activity was directly assayed by measuring the peak area of the produced β‐nicotinamide adenine dinucleotide phosphate and the decreased peak area indicated the aromatase inhibition. Using the Lineweaver–Burk equation, the Michaelis–Menten constant was calculated to be 50 ± 4.5 nM. The method was applied to the screening of aromatase inhibitors from 15 natural products. Seven compounds were found to have potent AR inhibitory activity.