Search results for "amine"
showing 10 items of 7299 documents
New Photosensitive Polymers: Synthesis and Free Radical Polymerization of Oxypyridinium and Oxyisoquinolinium Functionalized Methacrylate and Styren…
2002
Polymerizable hydroxypyridinium and hydroxyisoquinolinium salts 1a−4a, 2d, and 3d have been prepared from vinylbenzyl chloride or glycidyl methacrylate and 3-hydroxypyridine (2), 4- or 5-hydroxyisoquinoline (1, 3), and 8-hydroxyquinoline (4). Radical homo- and copolymerization with styrene or methyl methacrylate of the salts 1a−3a, 2d, and 3d produced (co)polymers 1e, 2e, 2f, 3f, 1g, 2g, 2h, and 3h. The photosensitive dipolar oxypyridinium or oxyisochinolinium betaine structures were generated in solutions with triethylamine from the low molecular weight and polymeric salt precursors. For the model compounds 1b−4b and (co)polymers 1e, 2e, 2f, 3f, 1g, 2g, 2h, and 3h, the degradation of the l…
Glycosylamines of 4,6-O-butylidene-α-d-glucopyranose: synthesis and characterization of glycosylamines, and the crystal structure of 4,6-O-butylidene…
2002
A total of nine glycosylamines of 4,6-O-butylidene-α-D-glucopyranose were synthesized using primary amines having various groups in their ortho- or para-positions. Among these, six are monoglycosylamines, including one primary glycosylamine, and three are bis-glycosylamines. All these compounds were characterized by 1H, 1H–1H COSY, 1H–13C COSY and 13C NMR spectroscopy and FTIR spectra. The FAB mass spectra provided the molecular weights of the products by exhibiting the corresponding molecular ion peaks. The crystal structure of 4,6-O-butylidene-N-(o-chlorophenyl)-β-D-glucopyranosylamine revealed the C-1 glycosylation, the β-anomeric nature, and the 4C1 chair conformation of the saccharide …
Reversal of asymmetric induction in stereoselective strecker synthesis on galactosyl amine as the chiral matrix
1988
Abstract The reversal of the direction of asymmetric induction in Lewis acid catalyzed Strecker synthesis using the 2,3,4,6-tetra-O-pivaloyl-β-D-galactopyranosyl amine 1 is described. In isopropanol or tetrahydrofuran 1 had given ( R )-diastereomers of the corresponding α-amino nitriles preferably. However, in chloroform in the presence of heterogeneous zinc chloride the same auxiliary alternatively leads to an excess of the ( S )-diastereomers.
3.13 Carbohydrate Derived Auxiliaries: Amino Sugar and Glycosylamine Auxiliaries
2012
The stereodifferentiating potential of carbohydrate auxiliaries is illustrated by examples of oxazolidinones derived from amino sugars and aldimines of glycosylamines. Taking advantage of the bicyclic structure of amino sugar-derived oxazolidinones, reactions of their unsaturated or deprotonated N -acyl derivatives show an efficient exo - versus endo -differentiation. High diastereoselectivity is achieved in the syntheses of β -branched or α -substituted carboxylic acid derivatives. Imines of glycosylamines, in particular of 2,3,4,6-tetra- O -pivaloyl- β - d -galactopyranosylamine, are characterized by a conformation stabilized through the exo -anomeric effect and by their ability to coordi…
Interaction of metal ions with N-glycosylamines: isolation and characterization of the products of 4,6-O-benzylidene-N-(o-carboxyphenyl)-β-D-glucopyr…
2001
Metal-ion complexes of Li+, Na+, K+, Mg2+, Ca2+, Ba2+, Pb2+, Cd2+, Hg2+ with 4,6–O–benzylidene–N–(o–carboxyphenyl)–β–D–glucopyranosylamine were synthesized and isolated as solid products and characterized by analytical means as well as by spectral techniques, such as, 1H and 13C NMR, FTIR, absorption, FAB mass spectrometry, optical rotation and CD. While the alkali metal ions formed ML type of complexes, the other metal ions formed ML2 type complexes. Molecular weights of the complexes of Li+, Na+ and K+ were established based on the molecular-ion peaks in the FAB mass spectra. The saccharide portion remians in the β-anomeric form even after the complexation. The spectral data, as well as t…
ChemInform Abstract: Synthetic O-Glycopeptides as Model Substrates for Glycosyltransferases.
2010
Abstract A new approach to O-glycopeptides of the glucosamine type is described. N-Urethane protected, peracetylated glucosamine is converted into its 1-thio (1-bromo) derivative and used for glycosylation of a variety of protected serine or threonine derivatives as acceptors. The urethane group is easily exchanged for the natural N-acetyl moiety and O-deacetylation is achieved with hydrazine/methanol. The resulting O-GlcNAc derivatives are subjected to an enzymatic galactosylation procedure using β-1,4-galactosyltransferase (EC 2.4.1.22) to furnish O-glycopeptides of the neolactosamine type.
Effect of phosphinothricin (glufosinate) on photosynthesis and photorespiration of C3 and C 4 plants.
1990
Phosphinothricin (glufosinate), an irreversible inhibitor of glutamine synthetase, causes an inhibition of photosynthesis in C3 (Sinapis alba) and C4 (Zea mays) plants under atmospheric conditions (400 ppm CO2, 21% O2). This photosynthesis inhibition is proceeding slower in C4 leaves. Under non-photorespiratory conditions (1000 ppm CO2, 2% O2) there is no inhibition of photosynthesis. The inhibition of glutamine synthetase by phosphinothricin results in an accumulation of NH4 (+). The NH4 (+)-accumulation is lower in C4 plants than in C3 plants. The inhibition of glutamine synthetase through phosphinothricin in mustard leaves results in a decrease in glutamine, glutamate, aspartate, asparag…
Sisäinen markkinointi johtamisena : tapaustutkimus konepajateollisuuden projektiorganisaatiosta
2009
The objective of this study was to increase the understanding of the management of internal marketing. The theoretical objective was to specify the mutual relation of the concepts of internal marketing and management. On the basis of an analysis of the two concepts and of research literature, a managerial model of the management of internal marketing was built as a theoretical frame of reference.The empirical part of the study examined how the members of the personnel in the case organization built their perception of internal marketing management in their mutual interaction on the basis of their experiences and their feelings. On the basis of the frame of reference model and the empirical …
Operations & Maintenance Business Model Transformation—Multiple Case Studies
2014
Capital goods companies’ service offering has been mainly to provide spare parts and maintenance work. In search of growth, these companies have expanded to new areas, such as Operations & Maintenance. Instead of operating and maintaining e.g. production processes itself, a customer can outsource a wide variety of managed services based on agreed service levels. There has been a special focus on global information management know-how, governance, process know-how, physical assets, and spare and wear parts. In order to get a good coverage of case studies, we selected five large global suppliers and two customer companies in telecommunication, energy, mining, and pulp and paper business. By i…
Effects of leflunomide on immune responses and models of inflammation.
1993
Leflunomide is an antiphlogistic and immunomodulating agent that has been shown to be effective in preventing and healing autoimmune disorders and reactions leading to organ graft rejection. From our preliminary clinical data [4], we now have hopes that these effects, observed in experimental animals, can truly be transferred to humans. Although we are far from understanding the mode of action of leflunomide, we are slowly gathering some insight. A good many of the immunosuppressive effects of leflunomide can be attributed to the antagonistic effects it has on responses to many cytokines, most likely through receptor expression and signal transduction (tyrosine kinase inhibition). The inhib…