Polysaccharides metal complexes

Poly(8-quinolinol) electrode coatings, 19 Polysaccharides metal complexes geochemistry, 868 Polyselenides metal complexes geochemistry, 854 Polytyramines electrode modification, 23 Polyvinylferrocene electrode coatings, 19 attachment, 19 Poly(N-vinylimidazole) metal complexes color photography, 109 Poly(4-vinylpyridine) electrode coatings, 17 redox centres, 17 electrodes, 16 Porins... 

Naturally, very long T,c values are expected for solids as viewed from the expected correlation time at the low temperature side of the T c minimum (0.1-0.2 s) as shown in Figure 1. Indeed, their values turns out to be the order of 10-30 s for carbon sites in the absence of internal fluctuations as in polysaccharides such as (1 — 3)-p-D-glucan and (1 —> 3)-p-D-xylan,46 8 fibrous proteins such as collagen49 and silk fibroin,50 free and metal-complexed ionophores,51 or in some instances up to 1000 s as in crystalline polyethylene.52... 

Asymmetric hydrogenations catalyzed by supported transition metal complexes have included use of both chiral support materials (poly-imines, polysaccharides, and polyalcohols), and bonded chiral phosphines, although there have been only a few reports in this area. 

Many chiral compounds can be used as selectors, for example, chiral metal complexes, native and modified cyclodextrins, crown ethers, macrocyclic antibiotics, noncyclic oligosaccharides, and polysaccharides all have been shown to be useful for efficient separation of different types of compounds. 

Cellulose and complex pectic polysaccharides are the main matrix of the water-insoluble residue after centrifugation of fruit and vegetable homogenates. The use of pectinolytic enzymes is therefore necessary to solubilize the solid sample. Pectinolysis is known to degrade efficiently large pectic polysaccharides, but some of them, for example, rhamnogalacturonan-II, are considered to be resistant to pectinolytic enzymes [45]. A mixture of commercial products Rapi-dase LIQ and Pectinex Ultra-SPL , was reported for the release of metal-complexes from the solid parts of edible plants, fmits, and vegetables [45]. 

Water-soluble polysaccharide species with higher molecular weights can be readily degraded by enzymic hydrolysis with a mixture of pectinase and hemi-cellulase to release the dRG-II complex [45]. The same mixture was found to be efFcient to extract the dRG-II D metal complexes from water-insoluble residues of vegetables, owing to the destruction of the pectic structure [45]. 

Other SO types and selectivity principles used in CE are related to polysaccharides (e.g. heparin, chondroitin sulphate, dextrin, etc.) (reviewed by Nishi 475 ). chiral crown-ethers, e.g. 18-crown-6 tetracarboxylic acid 293,476 and chiral metal complexes (ligand-exchange electrophoresis) 477. ... 

Glycosides are obtained by conversion of the cyclic semiacetal form of aldoses and ketoses to an acetal. We will focus on the metal complexes and esters of the following glycosides alkyl pyranosides, alkyl furanosides, non-reducing disaccharides, polysaccharides, and Anally the nucleosides as a member of the group of iV-glycosides. 

Pb " ", and Mn " " (Banerjee and Muklierjee, 1972 Tan, 1978 Piccolo and Stevenson, 1982). The extent of the OH stretching shift toward lower frequencies depends on the type of metal and follows the order Mn < Co < Cu < Fe (Banerjee and Mukherjee, 1972). Further, modifications of the typical band at 1070 cm" ascribed to polysaccharide components of FAs suggest that OH groups of these structures could also be involved in metal complexation (Prasad and Sinha, 1983). 

The field of application of this method is quite large, especially at the level of all classes of biological macromolecules, e.g., polysaccharides, antibiotics, natural metal complexes, etc. This is shown by the observation of ions with masses of 4000 units produced by peptides composed of 29 amino acid residues [84]. The method seems to be sensitive in the ng and pg range of sample detection. 

X. Preparation and Use of the Tetrazolium and Carbothionic Acid Phenylhydrazide Derivatives of the Oxidized Polysaccharides and the Metal Complexes of Their Formazans... 

From the formazans of oxidized polysaccharides, new nitrogenous polysaccharide derivatives and the metal complexes of their formazans can be prepared. Since the new reactive groups take the place of the formazan functions, their positions in the molecule depend on the method of oxidation by which the formazan groups were formed. 

Like the simple formazans, the formazans of oxidized polysaccharides form complexes with heavy metal salts with ease. On warming the formazans of oxidized cellulose, starch, dextrin, dextran, or inulin with copper, cobalt, nickel, or uranium salt solutions, their characteristically-colored metal complexes are obtained. The presence of carboxyl groups in the polysaccharide formazans frequently facilitates complex formation. ... 

Until the structure of the metal complexes of the polysaccharide formazans is more exactly known, structural formulas are suggested - in... 

Bifunctional catalysts can be obtained which couple the presence of a metal complex immobiUzed on the aerogel with the activity of the intrinsic functions of the polysaccharide. Metallophthalocyanine supported on chitosan is an example. 

Precipitation of Some Polysaccharides as Complexes with Metals ... 

Pirkle or brush type bonded phases Helical chiral polymers (polysaccharides) Cyclodextrins and crown ethers Immobilised enzymes Amino acid metal complexes Three-point interaction Attractive hydrophobic bonding Host guest interaction within chiral cavity Chiral affinity Diastereomeric complexation... 

For the construction of artificial metalloproteins, protein scaffolds should be stable, both over a wide range of pH and organic solvents, and at high temperature. In addition, crystal structures of protein scaffolds are crucial for their rational design. The proteins reported so far for the conjugation of metal complexes are listed in Fig. 1. Lysozyme (Ly) is a small enzyme that catalyzes hydrolysis of polysaccharides and is well known as a protein easily crystallized (Fig. la). Thus, lysozyme has been used as a model protein for studying interactions between metal compounds and proteins [13,14,42,43]. For example, [Ru(p-cymene)] L [Mn(CO)3l, and cisplatin are regiospecificaUy coordinated to the N = atom of His 15 in hen egg white lysozyme [14, 42, 43]. Serum albumin (SA) is one of the most abundant blood proteins, and exhibits an ability to accommodate a variety of hydrophobic compounds such as fatty acids, bilirubin, and hemin (Fig. lb). Thus, SA has been used to bind several metal complexes such as Rh(acac)(CO)2, Fe- and Mn-corroles, and Cu-phthalocyanine and the composites applied to asymmetric catalytic reactions [20, 28-30]. 

Interaction of fluorophores with natural biopolymers such as proteins, polysaccharides, or DNA is also an enantioselective process and can be used to discriminate between two enantiomers of a specific compound. A remarkable example is the differential interaction of A and A isomers of luminescent octahedric metal complexes with DNA (metallointercalators), which generate a fluorescent signal and was shown to be dependent on the DNA heUcity, as was reversed for right-handed B-DNA and left-handed Z-DNA [38], However, in most studies, the main interest has usually been to probe the biopolymer conformation and not to generate an enantioselective fluorescence response of the probe. 

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