Search results for "conjugate"
showing 10 items of 644 documents
Stabilization of anti-leukemic enzyme l-asparaginase by immobilization on polysaccharide levan
2001
Abstract Biologically active fructose polymer levan from Zymomonas mobilis of different molecular mass (75 and 2000 kDa) was covalently coupled to anti-leukemic enzyme Erwinia carotovora l -asparaginase. The method used for the immobilization of the enzyme involved periodate oxidation of the polysaccharide, followed by reductive alkylation. A gentle periodate oxidation of levan (oxidation degree ≤24%) resulted in the highest residual enzyme activity (≥55%). The K m(app.) of glycoconjugates was higher than the K m of native l -asparaginase. The conjugation of l -asparaginase widened the optimum pH range of the enzyme. The electrophoretic mobility in polyacrylamide gel of glycoconjugates obta…
On-Surface Synthesis of Oligo(indenoindene)
2020
Fully conjugated ladder polymers (CLP) possess unique optical and electronic properties, and are considered promis-ing materials for applications in (opto)electronic devices. Poly(indenoindene) is a CLP consisting of an alternating array of five- and six-membered rings, which has remained elusive so far. Here, we report an on-surface synthesis of oligo(indenoindene) on Au(111). Its structure and a low elec-tronic bandgap have been elucidated by low-temperature scanning tunneling microscopy and spectroscopy and non-contact atomic force microscopy, complemented by density functional theory calculations. Achieving defect-free seg-ments of oligo(indenoindene) offers an exclusive insight into th…
Synthesis and biopharmaceutical characterisation of new poly(hydroxyethylaspartamide) copolymers as drug carriers.
2001
Abstract Four new poly(hydroxyethylaspartamide)-based copolymers bearing (a) poly(ethylene glycol) 2000, (b) poly(ethylene glycol) 5000, (c) poly(ethylene glycol) 2000 and hexadecylalkyl, (d) poly(ethylene glycol) 5000 and hexadecylalkyle, as pendant groups were synthesised. The copolymers were obtained by partial aminolysis of polysuccinimide with poly(ethylene glycol) and hexadecylalkyl amino derivatives followed by reaction with ethanolamine. Naked polyhydroxyaspartamide was obtained by polysuccinimide reaction with ethanolamine. The nuclear magnetic resonance, infrared, light scattering and elemental analysis allowed for the extensive physico-chemical characterisation of the carriers. T…
Carbamate Linker Strategy in Solid-Phase Synthesis of Amino-Functionalized Glycoconjugates for Attachment to Solid Surfaces and Investigation of Prot…
2009
Amino-functionalized serine-based galactose and glucose neoglycolipids were prepared by solid-phase synthesis using a carbamate strategy for anchoring amino functionalities to a (2-fluoro-4-hydroxy ...
Synthesis and Photoluminescent Properties of 1,1‘-Binaphthyl-Based Chiral Phenylenevinylene Dendrimers
2003
New chiral, soluble binaphthyl derivatives that incorporate stilbenoid dendrons at the 6,6â²-positions have been prepared. The synthesis of the new enantiopure dendrimers was performed in a convergent manner by Horner-Wadsworth-Emmons (HWE) reaction of the appropriately functionalized 1,1â²-binaphthyl derivative (R)-1 and the appropriate dendrons (R)2nGn-CHO. Different electroactive units were incorporated in the peripheral positions of the dendrons in order to tune both the optical and electrochemical behavior of these systems. Fluorescence measurements on the chiral dendrimers reveal a strong emission with maxima between 409 and 508 nm depending upon the substitution pattern. Finally, t…
Donor-Acceptor Polythiophene Copolymers with Tunable Acceptor content for Photoelectric Conversion Devices
2004
The synthesis and characterization of a new series of substituted polythiophenes containing an electron acceptor anthraquinone moiety in the side chain are reported. The acceptor molar content was varied by the co-polymerization of both alkylthiophene and thiophene bearing anthraquinone monomers in different ratios. NMR analysis shows a good correlation between the monomer feed composition at the beginning of the polymerization and the actual unit composition of the backbone. The conjugation length and the chemical composition of the copolymers as a function of the molecular weight have been studied by size exclusion chromatography. Small angle X-ray scattering and UV-Vis absorption spectra…
Redox and Photochemistry of Bis(terpyridine)ruthenium(II) Amino Acids and Their Amide Conjugates – from Understanding to Applications
2014
Invited for the cover of this issue is the group of Katja Heinze at the Johannes Gutenberg University of Mainz, Germany. The cover image shows the bis(terpyridine)ruthenium(II) amino acid [Ru(4′-tpy-COOH)(4′-tpy-NH2)]2+ (tpy = 2,2′;6′,2″-terpyridine), illustrating some of its multifaceted optical and redox chemical properties as well as highlighting its potential applications in light-to-energy conversion and energy-to-light conversion schemes.
Intramuscular fatty acid composition of lambs given a tanniniferous diet with or without polyethylene glycol supplementation.
2007
The aim of this trial was to investigate the effects that dietary tannins have on lamb intramuscular fatty acids. Twenty-seven lambs were divided into three homogeneous groups: control group, receiving commercial concentrate based on maize; tannin group, fed a diet based on carob pulp (45% as fed basis); PEG group, receiving the same diet as the latter with addition of 42g/kg of polyethylene glycol (PEG, a binding agent that eliminates the effects of condensed tannins). The duration of the trial was 45 d. Intramuscular fatty acids were measured in the longissimus dorsi muscle. The isomer cis-9 trans-11 of linoleic acid (conjugated linoleic acid or CLA) and linolenic acid were higher in the …
Chemical Strategies for the Synthesis of Protein–Polymer Conjugates
2012
Protein-polymer conjugates have achieved tremendous attention in the last few years. The synergistic combination of properties has led to certain advantages in bio-applications. Over the past few years, numerous chemical strategies have been developed to conjugate different synthetic polymers onto proteins, most of which can be summarized within the scope of click-chemistry. Here we highlight conjugation strategies based on available functional groups present on the synthetic polymer and existing groups of proteins from the natural pool. In particular, the chapter organizes the various possible reactions by classes of functional groups present on protein surfaces, deriving from selected ami…
The effect of 2,2-dicyanovinyl groups as electron acceptors in push–pull substituted oligo(1,4-phenylenevinylene)s
2003
Abstract The newly synthesized oligo(1,4-phenylenevinylene) series 2a–d with bis(2-hexyloctyl)amino groups as electron donors and 2,2-dicyanovinyl groups as electron acceptors represents conjugated oligomers with strong push–pull effects. Due to the decrease of the intramolecular charge transfer with increasing numbers of repeat units (n=1–4), the long-wavelength transition shows a particularly great hypsochromic shift for the extension of the chromophore.