1,721,013 research outputs found
Selective modification of thymidine by dansyl group and biological effects of the dansyl derivatives
No full textLinear oligopeptides. XLIII. Study of the relationship between conformation and nature of side chain: Homologous series derived from γ-branched amino acid residues
No full textSynthesis and activity in photodynamic therapy of poly(ethylene glycol) conjugated pheophorbide
No full textPostsynthetic conjugation of biopolymers with high molecular mass poly(ethylene glycol): Optimization of a solution process tested on synthetic oligonucleotides
No full textThe reaction of oligonucleotides with high molecular weight monomethoxy poly(ethylene glycol)s (MPEGs) has been tested to set up a convenient procedure for the postsynthetic conjugation in solution of biopolymers. A first oligonucleotide was previously modified in 5', using a liquid-phase procedure, with a linker carrying a terminal primary amino group to enhance its nucleophilic reactivity. Two procedures commonly utilized for the activation of the terminal OH groups of the MPEG were evaluated, that is, the reaction with pNO(2)-phenyl chloroformate and with N,N-disuccinimidyl carbonate. Both water as well as organic solution conditions were employed and compared. In a second test, a X-amino modified, commercial 20-mer was also conjugated in a microscale condition to verify the effect of size and concentration of MPEG on the postsynthetic conjugation of these biopolymers under troublesome synthetic conditions
Photodynamic activity of pheophorbide from scutellaria barbata as a free molecule and conjugated to polyethylene glycol.
No full textLinear oligopeptides 29. Infrared conformational analysis of homo-oligopeptides in the solid state and in solution
No full textSynthesis of Unsymmetrical Methylene Derivatives of Benzopyran-4-ones from Mannich Bases
No full textLinear oligopeptides 55. Infrared conformational analysis of polyethylene glycol bound alanine and valine homooligopeptides in the solid state and in solution
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MultiPEGs: High Molecular Weight Multifunctional Poly(ethylene glycol)s Assembled by a Dendrimer‐Like Approach
No full textNew multifunctional, soluble and biocompatible polymeric systems exhibiting good physicochemical properties and good binding capacity have been obtained by assembly of smaller PEG components, selectively protected, purified and activated, by use of appropriate polyfunctional linkers. A general process for the synthesis of those derivatives was characterized by: a) selective derivatization of a PEG unit with a defined MW with an appropriate protecting group and activation of residual functional groups, and b) multiple condensation reactions of PEG units and linkers to provide multifunctional polyethylene glycol derivatives (MultiPEGs) of the desired size and complex structure. These complex-structured MultiPEGs have larger numbers of functional groups, and probably better biodegradability, than commercial PEGs of comparable molecular weight. They can be advantageously used as carriers or stabilizers of pharmacologically or biologically active substances, and also as soluble supports for reagents and catalysts in liquid-phase synthesis reactions. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheirn, Germany, 2005
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