The Studies of A New Type of Crystalline Antimonic Acid

A new type of crystalline antimonic acid Sb2O5 ·3H2O was synthesized. The composition, crystal structure, the equilibrium distribution coefficients for sodium and potassium ions and the ion-exchange capacity of this exchanger were determined. With this exchanger, sodium ions were removed from potassium chloride, and the content of sodium chloride was reduced from 3.24 % to 0.02% .Compared with other ion-exchange materials, the crystalline antimonic acid gives an unusual selectivity for potassium and sodium ions . The different compositions and properties of antimonic acid exchangers are obtained through different preparing conditions and its crystalline formula of Sb2O5 ·4H2O[2](C-SbA1) is currently accepted. This paper reports a new type of crystalline antimonic acid-Sb2O65·3H2O(C-SbA2), synthesized by an improved Kuzin's method[3]. Sodium ions are removed from potassium chloride with C-SbA2. The exchange efficiency is better than that of C-SbA1.     

Studies on a New Usage of Hypophosphorous Acid—iodine System in N—C Bond Cleavage

A mixture of hypophosphorous acid(H3PO2)and iodine in acetic acid can cleave the N-alkyl bond in a variety of N-1 substituted pyrimidine derivative in relatively high yields,without any damage to the amido bond in the non-nucleosides pyrimidine base skeleton.     

In-Situ Synthesis of Terbium Complex with Salicylic Acid in Silica Matrix by a Two-Step Sol-Gel Process

Sincesomelanthanideionspossessgoodlundnescentcharacteristicsbasedontheelectronictransitionsbetweenthe4fenergylevels,aseriesofrareearthcompoundshavebeenstudiedforpracticalapplicationsasphosphors.However,sincethef-ftransitionsoftheseionsareparityforbidden,theintensityofabsorptionbandsareusuallyrelativelyweak.Itiswellknownthatorganicligandsusuallyhavehighultravioletmolarabsorptivity.Ifthecomplexesthatcontainthiskindofligandsaresynthesized,theywillgivestrongluminescence.Infact,sofarmanyphotoactive…     

Nonaqueous Emulsions – A Versatile Tool for New Types of Functional Nanoparticles

Summary : The preparation of functional polymer latex particles is usually carried out in aqueous heterogeneous systems, i.e. for example in emulsion or mini-emulsion polymerization. Due to the presence of water, moisture sensitive reactions like step growth polymerizations or metal catalyzed reactions can not be accomplished without side reactions and / or decomposition. In order to avoid these side reactions, different nonaqueous emulsion systems have been developed. According to the desired polymerization procedure, these systems consist of a nonpolar organic phase surrounded by a perfluorinated solvent or of a polar organic phase which is dispersed in a nonpolar organic solvent. Both emulsions are stabilized by amphipolar block copolymers and result in long time stable particle dispersions. The resulting dispersions yield particles with narrow size distributions and – depending on the reaction conditions – diameters down to tens of nanometers. This technique allows the formation of particles consisting of numerous different classes of polymers, e.g. polyurethanes, polyesters, polyolefins etc. and the formation of more complex morphologies such as core shell structures.     

Development of a New Clean-up Method for the Determination of 5-methyl-tetrahydrofolate in Milk Samples Using a Sol-Gel β-Lactoglobulin Column

The specific forms of folic acid, a vitamin of the B-group, are generally determined in foods after sample clean-up using affinity columns containing folate binding protein covalently bound to a solid support material. The new approach described in the present paper is to isolate the target analyte by using the less costly milk protein β-lactoglobulin, entrapped in the pores of a sol-gel glass. Sol-gel β-lactoglobulin columns were included in a clean-up procedure developed to determine 5-methyl-tetrahydrofolate in milk samples. Concentrations of 5-methyl-tetrahydrofolate in milk samples with different fat contents ranged from 31 to 70 ng/ml. Repeated use of the β-lactoglobulin columns for sample preparation resulted in a decrease of analyte recovery. However, due to the high column to column reproducibility good results were obtained when the standard addition method was performed with columns which had already been used for the same number of sample clean-ups.     

A New Hybrid Model of Amino Acid Substitution for Protein Functional Classification

In recent years, methods of protein sequences analysis have been gradually evolved into two directions: One is based on the models of probability and statistics1-4; the other is based on the digital signal processing technologies 5-8. The latter mainly converts the protein character sequences into digital signals and uses some signal processing methods to analyze them, i.e., fast Fourier transform (FFT). However, it is still unsolved how to characterize the protein sequences accurately with …     

A New Tool in Metabolism Research—Combination of OPLC On-Line Radioactivity Detection with HPLC—RD Technique

JPC – Journal of Planar Chromatography – Modern TLC - This paper reports a recently developed technique, coupling of optimum-performance laminar chromatography (OPLC) with online...     

NMR Studies of a New Binding Mode of the Amino Acid Esters by Porphyrinatozinc(Ⅱ)

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A New β-Carboline Alkaloid and a New Derivate of Isoferulic Acid from Anemone altaica

A new β-carboline alkaloid, 4-（9H-β-carbolin-1-yl）-4-oxobutyric acid and a new derivate of isoferulic acid, （E）-3-（3-hydroxy-4-methoxyphenyl）acrylic acid carboxymethyl ester, were isolated from the roots of Anemone altaica. Their structures were determined on the basis of spectral data.     

A New Deoxygenation Method for Taxanes Using Hypophosphorous Acid

An efficient and practical radical chain deoxygenation method by phosphorus centered radicals generated from hypophosphorous acid was developed in the synthesis of analogues of paclitaxel.     

A New Biochemical Way for Conversion of CO2 to Methanol via Dehydrogenases Encapsulated in SiO2 Matrix

CO2 is converted to nethanol through an enzymatic approach using formate dehydrogenase(FateDH),formaldehyde dehydrogenase(FaldDH）and alcohol dehydrogenase(ADH)coencapsulated in silica gel prepared by modified sol-gel process as catalysts,TEOS as precursor,NADH as an electron donor.The highest yield of methanol was up to 92.1% under 37℃,pH7.0 and 0.3Mpa.     

Synthesis of a New Polyoxometalate Loaded Stearic Acid Nanoparticles

The stearic acid nanoparticles loaded polyoxometalate K6[γ-(CpTi)2SiW10O38][(CpTi)2SiW10] have been prepared and structurally characterized by elemental analysis, IR spectra.The particle size was estimated by transition electron microscope and zatesizer instrument. The result showed that the polyoxometalate retained the parent structure after encapsulation by stearic acid nanoparticles.     

A New Synthetic Route for 2,4-Dibromo-5-fluorobenzoic Acid

Fluoroquinolonesareeffectivemedicinesagainstbacteria,evenagainsttumor.Overtenexcellentfluoroquinol0nemedicineshavebeen0nthemarket.Duet0thehigherselectivity,yieldatbrondnationof3-flu0rotoluenethanchlorination,and0theradvantages'-',2,4-dibromo-5-flu0r0benzoicacidhasreplaced2,4-dichloro-5-fluor0-benzoicacidandbecomethekeystartingmaterialofpreparingfluoroquinoIonemedicines'.S0itisofgreatsignificancetofindaneffectivesyntheticpathfor2,4-dibromo-5-fluor0benz0icacid.Therehavebeenproposedtwomethodsf0r…     

StavroX—A Software for Analyzing Crosslinked Products in Protein Interaction Studies

Chemical crosslinking in combination with mass spectrometry has matured into an alternative approach to derive low-resolution structural information of proteins and protein complexes. Yet, one of the major drawbacks of this strategy remains the lack of software that is able to handle the large MS datasets that are created after chemical crosslinking and enzymatic digestion of the crosslinking reaction mixtures. Here, we describe a software, termed StavroX, which has been specifically designed for analyzing highly complex crosslinking datasets. The StavroX software was evaluated for three diverse biological systems: (1) the complex between calmodulin and a peptide derived from Munc13, (2) an N-terminal ß-laminin fragment, and (3) the complex between guanylyl cyclase activating protein-2 and a peptide derived from retinal guanylyl cyclase. We show that the StavroX software is advantageous for analyzing crosslinked products due to its easy-to-use graphical user interface and the highly automated analysis of mass spectrometry (MS) and tandem mass spectrometry (MS/MS) data resulting in short times for analysis. StavroX is expected to give a further push to the chemical crosslinking approach as a routine technique for protein interaction studies.     

In(OTf)3—A New Efficient Lewis Acid Catalyst for Stereoselective C-Glycosylation Reactions of Glycal Derivatives

Abstract

A variety of glycal derivatives reacted smoothly with allyltrimethylsilane and trimethylsilylcyanide in neat condition as well as in dichloromethane in the presence of 2–5 mol% of In(OTf)₃ affording the corresponding 2,3-unsaturated C-glycosides in excellent yields and moderate to excellent α-selectivities.     

A New Diterpene Acid from the Flowers of Heteropappus altaicus

A new compound, named heteraltaic acid was isolated from the flowers of Heteropappus altaicus (willd) Novopokr. The compound was elucidated as (5R, 6S, 8aS) -5-[2-(3-furyl) ethyl-5, 6, 8a-trimethyl-4a, 5, 6, 7, 8, 8a -hexahydro-l-naphthalenecarboxylic acid] by the combination of 1D and 2D NMR techniques (HSQC, HMBC) and X-ray analysis.     

A New Solid Sorbent System for Rapid Monitoring of Dehydrogenated Nicotine by Using Furfural-hydrochloric Acid

Nicotine is one of the highly toxic chemicals, belonging to tobacco alkaloid. Nicotine appears to be a promising tracer for environmental tobacco smoke (ETS) because of its specificity for tobacco and it presents relatively high concentrations in tobacco …     

A New Route for Synthesis of Entecavir

2-Amino-1,9-dihydro-9-[(1S,3R,4S)-4-hydroxy-3-(hydroxymethyl)-2-methylenecyclopen tyl]-6H-purin-6-one (entecavir, Scheme 1) is a novel carbocyclic 2-deoxyguanosine analog drug which has potent and selective anti hepatitis B virus (HBV) activity1-3. Entecavir is also effective against lamivudine-resistant YMDD mutants4. The US Food and Drug Administration (FDA) approved entecavir as a new preferred drug for the treatment of HBV after lamivudine in March, 2005. Scheme 1 The structure o…     

Non-Covalent Postfunctionalization of Dye Layers on TiO2 — A Tool for Enhancing Injection in Dye-Sensitized Solar Cells

We report on newly tailored dye layers, which were employed, on one hand, for covalent deposition and, on the other hand, for non-covalently post-functionalizing TiO₂ nanoparticle films. Our functionalization concept enabled intermixing a stable covalent attachment of a first layer with a highly versatile and reversible hydrogen bonding through the Hamilton receptor–cyanuric acid binding motif as a second layer. Following this concept, we integrated step-by-step a first porphyrin layer and a second porphyrin/BODIPY layer. The individual building blocks and their corresponding combinations were probed with regard to their photophysical properties, and the most promising combinations were implemented in dye-sensitized solar cells (DSSCs). Relative to the first porphyrin layer adding the second porphyrin/BODIPY layers increased the overall DSSC efficiency by up to 43 %.     

A New Hapten for Immunoassay of Aldicarb

Aldicarb, 2-methyl-2-(methylthio)propionaldehyde O-(methylcarbamoyl)oxime, is a systemic N-methylcarbamate insecticide and has been used on a variety of crops. It is moderately water soluble and considered as one of the most acutely toxic pesiticides. Ald…