淫羊藿根与叶活性成分的分析和比较

采用细胞膜色谱法（ＣＭＣ）筛选，并结合离体药理实验确定主要活性成分，利用高效液相色谱法分析比较了淫羊藿根与叶中的活性成分及其差异性．色谱条件为Ｋｒｏｍａｓｉｌ ＯＤＳ 柱（１５０ ｍｍ× ４．６ ｍｍ．Ｉ．Ｄ ）流动相甲醇－水（７０：３０，Ｖ：Ｖ）；检测波长２７０ｎｍ。筛选发现淫羊藿根中的两个有效成分ＹＹＨ－２１４和ＹＹＨ－２１６对血管有较强的舒张作用，表明活性成分在ＣＭＣ模型体系中的保留特性与药理作用之间存在良好的相关性。在此色谱条件下淫羊藿叶未检测到这两种活性成分．     

A microtiter plate assay for the detection of inhibitors of the Na +, K + -ATpase

A rapid microtiter plate assay for the detection of inhibitors of the Na⁺, K⁺-ATPase has been developed. The assay is based on the measurement of inorganic phosphate released from the substrate, ATP, and has been designed to be carried out in the individual wells of a microtiter plate. Since the production of inorganic phosphate is determined colorimetrically, multiple samples can be tested simultaneously using a microtiter plate reader. This microtiter plate assay is particularly useful for screening large numbers of samples, such as microbial culture supernatants.     

Spectroscopic and biological studies on newly synthesized nickel(II) complexes of semicarbazones and thiosemicarbazones

Nickel(II) complexes, having the general composition Ni(L)2X2, have been synthesized [where L: isopropyl methyl ketone semicarbazone (LLA), isopropyl methyl ketone thiosemicarbazone (LLB), 4-aminoacetophenone semicarbazone (LLC) and 4-aminoacetophenone thiosemicarbazone (LLD) and X=Cl-, 1/2SO(4)2-]. All the Ni(II) complexes reported here have been characterized by elemental analyses, magnetic moments, IR, electronic and mass spectral studies. All the complexes were found to have magnetic moments corresponding to two unpaired electrons. The possible geometries of the complexes were assigned on the basis of electronic and infrared spectral studies. Newly synthesized ligand and its nickel(II) complexes have been screened against different bacterial and fungal growth.     

Cross-linking chemistry and biology: development of multifunctional photoaffinity probes

An efficient method of photoaffinity labeling has been developed based on rationally designed multifunctional photoprobes. Photoaffinity techniques have been used to elucidate the protein structure at the interface of biomolecules by the photochemical labeling of interacting sites. However, the identification of labeled sites within target proteins is often difficult. Novel biotinyl bioprobes bearing a diazirine photophore have contributed significantly to the rapid elucidation of ligand binding sites within proteins, thereby extending conventional photoaffinity methods. This article discusses the synthesis and applications of various photoprobes bearing a biotin, including strategies using cleavable linkages between photophores. The combination of photoaffinity methods with chip technology is also described as a novel entry to rapid affinity-based screening of inhibitors. This review focuses on a rapid and reliable photoaffinity method utilizing diazirine-based multifunctional photoprobes with numerous potential applications in functional proteomics of biomolecular interactions.     

NMR spectroscopy techniques for screening and identifying ligand binding to protein receptors

Binding events of ligands to receptors are the key for an understanding of biological processes. Gaining insight into protein-protein and protein-ligand interactions in solution has recently become possible on an atomic level by new NMR spectroscopic techniques. These experiments identify binding events either by looking at the resonance signals of the ligand or the protein. Ideally, both techniques together deliver a complete picture of ligand binding to a receptor. The approaches discussed in this review allow screening of compound libraries as well as a detailed identification of the groups involved in the binding events. Also, characterization of the binding strength and kinetics is possible, competitive binding as well as allosteric effects can be identified, and it has even been possible to identify ligand binding to intact viruses and membrane-bound proteins.     

High throughput screening of O-glycosylation conditions

We report a novel methodology for rapid and quantitative screening of O-glycosylation reactions of application to the analysis of parallel reaction systems. Our system exploits perdeuterated benzyl (Bn-d₇) ether, and stereoselectivity and yield are evaluated by ¹H NMR and MALDI-TOF MS, respectively. This paper summarizes over 240 screenings of 1 → 3 linkage formation between glucose residues targeting the α-isomer in high yield.     

Self-avoiding walks on random fractal environments

Self-avoiding random walks (SAWs) are studied on several hierarchical lattices in a randomly disordered environment. An analytical method to determine whether their fractal dimensionD _saw is affected by disorder is introduced. Using this method, it is found that for some lattices,D _saw is unaffected by weak disorder; while for othersD _saw changes even for infinitestimal disorder. A weak disorder exponent is defined and calculated analytically [ measures the dependence of the variance in the partition function (or in the effective fugacity per step)vL on the end-to-end distance of the SAW,L]. For lattices which are stable against weak disorder (<0) a phase transition exists at a critical valuev=v ^* which separates weak- and strong-disorder phases. The geometrical properties which contribute to the value of are discussed.     

Nonuniversality and analytical continuation in moments of directed polymers on hierarchical lattices

We prove the moments of the directed polymer partition function GZ, using an exact position space renormalization group scheme on a hierarchical lattice. After sufficient iteration the characteristic functionf(n)=lnGZⁿ of the probability (Z) converges to a stable limitf ^*(n). For smalln the limiting behavior is independent of the initial distribution, while for largen,f ^*(n) is completely determined by it and is thus nonuniversal. There is a smooth crossover between the two regimes for small effective dimensions, and the nonlinear behavior of the small moments can be used to extract information on the universal scaling properties of the distribution. For large effective dimensions there is a sharp transition between the two regimes, and analytical continuation from integer moments ton0 is not possible. Replica arguments can account for most features of the observed results.     

颜色指示法高通量筛选多相催化材料

介绍一种简单的组合化学技术, 用来筛选或优化多相催化反应中的催化剂. 在酯化反应中, 用甲基橙指示剂指示酯化反应的进程并对沸石的类型, 不同碳链的醇和酸的催化活性进行研究. 在光催化反应中, 选择甲基橙、罗丹明B作为反应物. 通过颜色变化, 对不同方法制备的TiO2进行高通量筛选.