Polymeric carrier resins

Polymeric carrier resins for catalytic or chromatographic applications (e.g. ion exchange resins)... 

Off-resin analysis is analysis of a compound cleaved off a polymeric carrier material, usually in solution. 

Besides classical resin beads, other polymeric carriers were also used for the synthesis ofpeptide libraries in various formats. Poly aery late-grafted polypropylene pins were used for the synthesis of the first combinatorial chemical library [1,2], This type of support continues to be heavily used in multiple peptide [27] and non-peptide [28] library synthesis. Cellulose paper, originally used by Frank et al. as a solid-phase support for oligodeoxy-ribonucleotide synthesis [29], has also been used as the support for multiple SPOT synthesis of peptide libraries [30,31], Polystyrene-grafted polyethylene film (PS-PE) may also be used in combinatorial peptide library synthesis [32], The specific feature of the membrane type of carrier is its dividability. This feature has been used for the synthesis of libraries with a nonstatistical distribution of library members, where no compound is missing and none is represented more than once [33],... 

The use of insoluble polymeric carriers has greatly simplified the synthesis of peptides purification of the growing peptide chain in the repetitive steps is achieved by filtration procedures that simply remove all soluble reagents and byproducts from the reaction medium, whilst the covalently resin-hnked macromolecule is retained on the insoluble polymeric support. In all sohd-phase reactions of this type, the polymeric support represents the medium on or in which the chemical reaction takes place. Correspondingly, this medium is represented by the total amount of insoluble polymer present, which in the case of polymeric beads is divided into small, individual reaction compartments. Resin parameters such as the degree of crosshnking, the polarity of the resin, its sweUing properties, mass-transport, phase transitions, bead size, and the particle size distribution therefore have to be taken into serious consideration. 

Besides the classical polymer introduced by Merrifield (1%-crosslinked chloromethylated polystyrene), a broad variety of polymeric supports is available for SPPS and some of the most popular resins are summarized in Table 1. The chemical structures of some selected resins are presented in Figure 1 and electron micrographs of several examples are displayed in Figure 2. In addition to the solid supports listed in Table 1, there are several other carriers used in peptide synthesis such as the gel-type and macroporous poly(meth-acrylates), coated surfaces like polystyrene films on polyethylene (PEt) sheets, polystyrene-coated polyethylene or polytetrafluoroethylene, and modified glass surfaces. (For recent reviews on polymeric carriers see refs . )... 

A problem which arises after cleavage not only from polystyrene-based polymeric carriers is the presence of impurities derived presumably from linker or resin components [57]. The occurrence of these impurities hampers routine product analysis and may have considerable influence also on the screening assay. In the mass spectrometric analysis, they can compete with poorly ionizable products, thus inhibiting a reliable analysis. At worst, they may even preclude detection of the expected compound, leading to a misinterpretation of the synthesis results. It has been found that the extraneous signals in the mass spectra are primarily dependent upon the type of resin used. Differences between analogous resins from different suppliers, or even different charges are also observed. As yet, it has not been possible to characterize these impurities with the methods of mass spectrometry and NMR. 

Appropriate polymeric carriers can be obtained from polymeric, oligomeric, and monomeric precursors. Due to unwanted chemical Interaction of such chemicals with the cell material larger size of these precursors Is favorable. The Ionotropic gelation, starting from polyelectrolytes and the polycondensation, starting from oligomeric epoxy resins, are typical problem solutions. 

Synonims 1,2-cyclohexanedicarboxylic, acid calcium salt octacosanoic acid, calcium salt (2 1) calcium difluoride propanedioic acid, calcium salt (1 1) 1,5-pentane dicarboxylic acid, calcium salt (lR,2R,3S,4S)-rel-bicyclo[2.2.1]heptane-2,3-dicarboxylic acid, disodium salt mixture of polycarbonic acid salt and inorganic carbonate in a polymeric carrier, sodium 2,2 -methylene-bis-(4,6-di-tert-butylphenyl)phosphate bicyclic (2,2,1) heptane di-carboxylate 1,2-cyclohexanedicarboxylic acid, calcium salt -i- zinc stearate bicyclo[2.2.1]heptane-2,3-dicarbo lic acid, disodium salt, (IR, 2R, 3S, 4S)-rel-and a blend of amorphous silicon dioxide coated wilh 13-docosenamide in a 1 1 ratio proprietary zinc compound octacosanoic acid, calcium salt (2 1) benzoic acid, lithium salt zinc monoglycerolate sodium benzoate encapsulated sodium salts of carbonic and poly-carboxylic acids with styrene and SEES rubber carrier resins zinc,[l,2,3-propanetriolato(2-)-k01,k02]homopolymer, stereoisomer... 

Carbon blacks are incorporated into polymeric media by one of two methods. The proper amount of carbon black may be dispersed directly into the polymer using a suitable mixing device. Far more common, however, is the masterbatch process in which carbon black is first dispersed into a carrier resin in concentrations of 30-50%. This concentrate is then let down (diluted) via the salt and pepper procedure attained by introducing a mixture of concentrate and polymer pellets into the mixing unit. The ratio of compound to pellets is adjusted to provide for the final carbon black loading. 

Bipyridine resembles nicotine in its pharmacological properties but is not as active. The 3,4 -bipyridine derivative 113 known as amrinone and its relatives are of interest as cardiotonic agents. 4,4 -Bipyridine has been tested as an insecticide, but it is not of practical value.It is used in the study of the electrochemistry of cytochrome c and acts as a polymerization catalyst or hardening agent for various resins. l-Hexyl-4,4 -bipyridinium salts are especially effective as electron carriers in photochemical hydrogen producing systems. l,l -Dimethyl-4,4 -bipyridinium (92 R = R = CHj) and l,l -dibenzyl-4,4 -bipyridinium... 

Methyl chloride is used in the production of tetramethyllead antiknock compounds for gasoline and methyl silicone resins and polymers, and as a catalyst carrier in low-temperature polymerization (e g., butyl rubber), a refrigerant, a fluid for thermometric and thermostatic equipment, a methylating agent in organic synthesis, an extractant and low-temperature solvent, a herbicide, a topical antiseptic, and a slowing agent (lARC, 1986 Lewis, 1993). 

Spray methods for obtaining microspheres have a number of disadvantages. High temperatures and bulky and complicated equipment are needed moreover they pose fire and explosion hazards. Low temperature methods, such as using emulsified thermoplast solutions, saturated polyester resins in liquid heat carriers, or suspension polymerization, are preferable1,3S). 

Particulates are commonly classified into micro- and nanoparticles based on the size of the particles. Nanoparticles are colloidal particles ranging from 10 to 1,000 run, in which drag may be entrapped, encapsulated, and/or absorbed. Microparticulates are drag-containing small polymeric particles (erodible, non-erodible or ion-exchange resins) within the size of 1-10 /on, which are suspended in a liquid carrier medium. 

One of the first non-formaldehyde fluorescent dye carrier systems for polyolefins was based on the reaction of polyfunctional amines with polyfunctional carboxylic acids to form relatively short chain polyamides [5].These linear thermoplastic resins showed good solubility and friability making them suitable for the incorporation of dyes, which offered increased protection from thermal and UV degradation. This fluorescent resin showed a dramatic increase in color retention upwards of 288°C, even after a 10 minute hold period at this temperature. Due to its non-ide-alized polymeric nature, the polyamide chemistry suffered from preferential plating out or migration of polar oligomeric species not incorporated into the polymer chains. 

Most of the carriers used in organic synthesis are lightly crosshnked gel-type resins. In contrast to macroreticular (macroporous) resins which are characterized by a permanent porosity, the gelatinous resins have to swell in appropriate solvents in order to build up the polymeric network and to make the reactive sites located on the polymeric strands accessible to the reactants. Good swelling properties are therefore essential for these gel-type resins. The functional groups are introduced either by copolymerization with functionalized monomers or by a posteriori functionalization of the polymeric component. Thus the reactive sites are statistically distributed on the polymer chains and more than 99% are positioned inside the polymeric beads and not on the surface. 

Our studies on solvent-impregnated resins, consisting of soluble compounds of type IB impregnated onto macroporous polymer carriers, have enabled us to conclude that a hydrophilic or amphiphilic component must be present in the polymeric network, in order to allow for fast ion diffusion inside the polymeric matrix. It is imperative that this component possesses none or minimal metal-ligand properties, so that it will not interfere with the ion selectivity of the main chelating group [6,7]. 

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