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Polymer Support (polymer + support)
Selected AbstractsChemInform Abstract: A New Homogeneous Polymer Support Based on Syndiotactic Polystyrene and Its Application in Palladium-Catalyzed Suzuki,Miyaura Cross-Coupling Reactions.CHEMINFORM, Issue 9 2010Jihoon Shin Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Synthesis of a library of 1,2,3,7-tetrasubstituted indolizines using poly(ethylene glycol) as soluble supportJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 3 2006Guizhou Yue A library of 1,2,3,7-tetrasubstituted indolizines has been synthesized using poly(ethylene glycol) (PEG) as soluble polymer support. The PEG-bound pyridinium salts reacted with alkenes or alkynes in the presence of Et3N via 1,3-dipolar cycloaddition to give PEG-bound indolizine derivatives, which were cleaved by 1 % KCN/MeOH to afford 1,2,3,7-tetrasubstituted indolizines in good to excellent yields. [source] Poly(styrene- co -glycerol dimethacrylate): Synthesis, characterization, and application as a resin for gel-phase peptide synthesisJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 19 2005Michael Roice Abstract An efficient cross-linked polymer support for solid-phase synthesis was prepared by introducing glycerol dimethacrylate cross-linker to polystyrene network using free radical aqueous suspension polymerization. The support was characterized by various spectroscopic methods. Morphological feature of the resin was analyzed by microscopy. The polymerization reaction was investigated with respect to the effect of amount of cross-linking agent, which in turn vary the swelling, loading, and the mechanical stability of the resin. The solvent uptake of the polymer was studied in relation to cross-linking and compared with Merrifield resin. The stability of the resin was tested in different synthetic conditions used for solid-phase peptide synthesis. Hydroxy group of the support was derivatized to chloro and then amino groups using different reagents and reaction conditions. Efficiency of the support was tested and compared with TentaGelÔ resin by following different steps involved in the synthesis of the 65,74 fragment of acyl carrier protein. The results showed that the poly(styrene- co -glycerol dimethacrylate) (GDMA-PS) is equally efficient as TentaGel resin in peptide synthesis. The purity of the peptides was analyzed by HPLC and identities were determined by mass spectroscopy and amino acid analysis. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4382,4392, 2005 [source] Synthesis, characterization and application of poly[(1-vinyl-2-pyrrolidone)- co -(2-hydroxyethyl methacrylate)] as controlled-release polymeric system for 2,4-dichlorophenoxyacetic chloride using an ultrafiltration techniquePOLYMER INTERNATIONAL, Issue 7 2008Guadalupe del C Pizarro Abstract BACKGROUND: Polymers supporting chemicals used in agriculture have recently been developed to overcome the serious environmental problems of conventional agrochemicals. The success of these formulations is based on a suitable choice of polymer support. Degradable polymeric hydrogels are of particular interest. The gradual release of the bioactive agent can be achieved by hydrolytic or enzymatic cleavage of the linking bond. RESULTS: In this context, poly[(1-vinyl-2-pyrrolidone)- co -(2-hydroxyethyl methacrylate)] [poly(NVP- co -HEMA)] has been used as a bioactive carrier reagent. Herein, we report a controlled-release system with the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) using an ultrafiltration system. Hydrolysis was studied by testing the release at various pH values. A high release with poly(NVP- co -HEMA),2,4-D was observed at pH = 7 and 10 after two days (Z = 2). The release percentage of copolymer,herbicide increased at pH = 10. It showed release values between 79.0 and 94.5%. Poly(NVP- co -HEMA),herbicide can release a bioactive compound in aqueous solution at pH = 3, 7 and 10. CONCLUSION: Based on the results of homogeneous hydrolysis, it is argued that the herbicide release rate depends on the pH of the reaction environment. This functional polymer could be employed as a biodegradable material for applications in agrichemical release. Copyright © 2008 Society of Chemical Industry [source] Bioartificial dextran and poly[ethylene- co -(vinyl alcohol)] hybrid sponges as support for proteinsPOLYMER INTERNATIONAL, Issue 10 2005D Silvestri Abstract A biological,synthetic hybrid material was prepared as a support for proteinic molecules. To control the conformational stability and ,vitality' of the entrapped compound, an enzyme, which catalyses a chemical reaction, was chosen. The physical immobilisation of ,-amylase on a novel biological,synthetic hybrid material was realised using a synthetic (poly[ethylene- co -(vinyl alcohol)]) and a biological (dextran) component. The supports were obtained in the form of porous sponges using the phase inversion process. The kinetic parameters of enzymatic hydrolysis of soluble starch were obtained by determining the maltose (reaction product) concentration in the test solution by a spectrophotometric method. A high amount of enzyme (10 and 15 mg per g of polymer matrix) was successfully entrapped in the polymer support and a rather good enzyme activity of entrapped ,-amylase and a constant activity for repeated use, compared with native ,-amylase, were observed. The results obtained clearly indicated that the bioartificial polymer sponges, showing an immobilisation of ,-amylase with maintenance of the catalytic function of the enzyme, can be used as suitable supports for proteins. Copyright © 2005 Society of Chemical Industry [source] High-performance affinity chromatography with immobilization of protein A and L-histidine on molded monolithBIOTECHNOLOGY & BIOENGINEERING, Issue 5 2002Quanzhou Luo Abstract Reactive monoliths of macroporous poly(glycidyl methacrylate- co -ethylene dimethacrylate) have been prepared by "in-situ" copolymerization of the monomers in the presence of porogenic diluents. Protein A and L-histidine were immobilized on the monoliths directly or through a spacer arm, respectively. The properties of these two kinds of affinity columns were characterized, and the results showed that the columns with coupling of ligands by a spacer arm have some extent of non-specific adsorption for bovine serum albumin. The affinity column based on the monolithic polymer support provided us with good hydrodynamic characteristic, low flow resistance, and easy preparation. These two affinity columns were used for the purification of immunoglobulin G from human serum. The purity of the purified IgG was detected by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The stability of the protein A affinity column was investigated, and its performance remained invariable after half a year. The effects of the nature and the pH of the buffer system on the adsorption capacity of human IgG on histidyl affinity column were also investigated. The protein A affinity column is favorable for rapid analysis of human IgG samples. In contrast, the advantages of mild elution conditions, high stability, as well as low cost provide the histidyl column further potential possibility for fast removal of IgG from human plasma in clinical applications. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 80: 481,489, 2002. [source] Donor-Bound Glycosylation for Various Glycosyl Acceptors: Bidirectional Solid-Phase Semisynthesis of Vancomycin and Its DerivativesCHEMISTRY - AN ASIAN JOURNAL, Issue 1 2007Takayuki Doi Prof. Abstract The glycosidation of a polymer-supported glycosyl donor, N -phenyltrifluoroacetimidate, with various glycosyl acceptors is reported. The application of the polymer-supported N -phenyltrifluoroacetimidate is demonstrated in the synthesis of vancomycin derivatives. 2- O -[2-(azidomethyl)benzoyl]glycosyl imidate was attached to a polymer support at the 6-position by a phenylsulfonate linked with a C13 alkyl spacer. Solid-phase glycosidation with a vancomycin aglycon, selective deprotection of the 2-(azidomethyl)benzoyl group, and glycosylation of the resulting 2-hydroxy group with a vancosamine unit were performed. Nucleophilic cleavage from the polymer support with acetate, chloride, azido, and thioacetate ions provided vancomycin derivatives in pure form after simple purification. The semisynthesis of vancomycin was achieved by deprotection of the acetate derivative. [source] Aryl acrylate based high-internal-phase emulsions as precursors for reactive monolithic polymer supportsJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 2 2005Peter Krajnc Abstract Water-in-oil high-internal-phase emulsions (HIPEs), containing 4-nitrophenyl acrylate and 2,4,6-trichlorophenyl acrylate as reactive monomers, were prepared and polymerized, and highly porous monolithic materials resulted. The novel materials were studied by combustion analysis, Fourier transform infrared spectroscopy scanning electron microscopy, mercury porosimetry, and N2 adsorption/desorption analysis. With both esters, cellular macroporous monolithic polymers were obtained; the use of 4-nitrophenyl acrylate resulted in a cellular material with void diameters between 3 and 7 ,m and approximately 3-,m interconnects, whereas the use of 2,4,6-trichlorophenyl acrylate yielded a foam with void diameters between 2 and 5 ,m, most interconnects being around 1 ,m. The resulting monoliths proved to be very reactive toward nucleophiles, and possibilities of functionalizing the novel polymer supports were demonstrated via reactions with amines bearing additional functional groups and via the synthesis of an acid chloride derivative. Tris(hydroxymethyl)aminomethane and tris(2-aminoethyl)amine derivatives were obtained. The hydrolysis of 4-nitrophenylacrylate removed the nitrophenyl group, yielding a monolithic acrylic acid polymer. Furthermore, functionalization to immobilized acid chloride was performed very efficiently, with more than 95% of the acid groups reacting. The measurement of the nitrogen content in 4-nitrophenyl acrylate poly(HIPE)s after various times of hydrolysis showed the influence of the total pore volume of the monolithic polymers on the velocity of the reaction, which was faster with the more porous polymer. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 296,303, 2005 [source] Using polymers to control substrate, ligand, or catalyst solubilityJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 14 2001David E. Bergbreiter Abstract The attributes and design of soluble polymer supports for catalysis and synthesis are discussed. By manipulating polymer structure, polymer supports can be prepared so that the solubility of an attached reagent, substrate, or ligand is affected by heating, cooling, pH, or solvent identity. Supports with such engineered solubility are useful both in organic synthesis and catalysis. They can be used as purification handles in organic synthesis as a way to recover catalysts, as a way to turn reactions on or off, and more generally, as a handle for separations. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2351,2363, 2001 [source] | |||||||||||||