Search results for "Succinic anhydride"
showing 10 items of 14 documents
Succinate-bonded pullulan: An efficient and reusable super-sorbent for cadmium-uptake from spiked high-hardness groundwater.
2015
Abstract Chemically modified pullulan was evaluated for its sorption efficiency and selectivity to remove cadmium (Cd) from spiked high-hardness groundwater (GW). Pullulan esterified with succinic anhydride using dimethylaminopyridine showed a fairly high degree of substitution value as confirmed by 1 H NMR spectroscopy. Pullulan succinate (Pull-Suc) was converted into the sodium salt (Pull-Suc-Na). The effect of contact time (5–200 min) and pH (2–8) on Cd-uptake by the sorbent (Pull-Suc-Na) was investigated. The sorbent showed more than 90% Cd-removal in first 15 min from distilled water (DW) and GW solution, respectively. Comparison of Pull-Suc-Na with other polysaccharidal sorbents sugge…
DIFFERENTIAL SCANNING CALORIMETRY STUDY ON DRUG RELEASE FROM AN INULIN-BASED HYDROGEL AND ITS INTERACTION WITH A BIOMEMBRANE MODEL:pH AND LOADING EFF…
2008
Inulin has been derivatized with methacrylic anhydride (MA) and succinic anhydride (SA) to obtain a methacrylated/succinilated derivative (INU-MA-SA) able to produce a pH sensitive hydrogel after UV irradiation. The hydrogel was characterized and loaded with diflunisal (10.4, 17 and 24%, w/w) chosen as a model drug. The drug release from INU-MA-SA-based hydrogel to a biomembrane model made by unilamellar vesicles of dimyristoylphosphatidyl-choline (DMPC) was investigated at pH 4.0 and 7.4 by differential scanning calorimetry (DSC) that appears to be a suitable technique to follow the transfer kinetics of a drug from a controlled release system to a biomembrane model. The drug release from t…
Inulin-iron complexes: a potential treatment of iron deficiency anaemia.
2007
The aim of this work was that to synthesize macromolecular derivatives based on inulin able to complex iron and useful in the treatment of iron deficiency anaemia. Carboxylated or thiolated/carboxylated inulin derivatives were obtained by single or double step reactions, respectively. The first one was obtained by reaction of inulin (INU) with succinic anhydride (SA) alone obtaining INU-SA derivative; the second one was obtained by the reaction of INU with succinic anhydride and subsequent reaction of INU-SA with cysteine; both derivatives were treated with ferric chloride in order to obtain the INU-SA-Fe(III) and INU-SA-Cys-Fe(III) complexes. Both complexes showed an excellent biodegradabi…
Nanoaggregates Based on New Poly-Hydroxyethyl-Aspartamide Copolymers for Oral Insulin Absorption
2013
The aim of this work was to produce copolymers with an appropriate hydrophilic/hydrophobic balance able to form nanoaggregates with protein molecules and to be used as ideal materials in the field of oral peptide/protein delivery. New anionic polymers obtained by the conjugation of carboxy-bearing ligands, like succinic anhydride and/or cysteine, to hydrophobized α,β-poly(N-2-hydroxyethyl)-dl-aspartamide (PHEA) copolymers have been synthesized and characterized. Starting copolymer was synthesized by the partial derivatization of hydroxyl groups on the PHEA backbone with butylamine (C4) (obtaining the PHEA-C4 copolymer, bearing a butyl moiety). The consecutive reaction of PHEA-C4 with succin…
A new synthesis and crystal structure of n-(2-hydroxyethyl)succinimide
1988
Abstract N-(2-Hydroxyethyl) succinimide was formed with 80 % yield in the reaction of 2-oxazolidinone with succinic anhydride at 210° C instead of polyesteramides obtained from N-substituted 2-oxazolidinones. The identification based on the crystal structure determination.
Synthesis of Polymer Colloids Using Polymerizable Surfactants
2001
A series of new anionic surfactants were prepared by reacting a polymerizable alcohol with either maleic or succinic anhydride, as well as sulfosuccinic anhydride, resulting in either bireactive or monoreactive surfactants, either carboxylated or sulfonated. The synthesis presented and the critical micelle concentration (CMC) determined. These compounds were engaged in the emulsion polymerization of styrene in batch and also in semi-batch seeded copolymerization producing core-shell latexes. The core was a polystyrene seed prepared using sodium dodecyl sulfate (SDS), thoroughly purified through ion exchange resins. The seed was then swollen overnight with a small amount of a 1 : 1 mixture o…
CONTROLLED RELEASE OF IgG BY NOVEL UV INDUCED POLYSACCHARIDE/POLY(AMINO ACID)HYDROGELS
2009
The development of new protein and peptide drugs needs new delivery systems able to entrap such drugs in safe conditions without affecting their structure and biological activity. In this context, the present work reports a new approach to load IgG, used as a model of therapeutic proteins such as anti-TNF-alpha monoclonal antibodies, into a polymeric system able to release the entrapped IgG in a controlled manner. In particular, new polysaccharide/poly(amino acid) UV induced hydrogels are proposed as colon delivery systems for human IgG. The poly(amino acid), alpha,beta-poly[N-(2-hydroxyethyl)-D,L-aspartamide], has been functionalized with methacrylic anhydride, while the polysaccharide, in…
Chain-extending of Hydroxytelechelic Polybutadiene: Synthesis and Characterization
2010
Extension of hydroxytelechelic polybutadiene oligomers ( 3200 g/mol) is performed in mild conditions, in order to avoid backbone modifications, using succinic anhydride or methylenedicyclohexyl diisocyanate. The two routes present significative extension of the initial oligomers. Extension through the anhydride route, in the presence of DCC and DMAP, leads to new hydroxytelechelic oligomers ( 8000 g/mol). Extension through the diisocyanate route, catalyzed by DBTL at 65°C leads to hydroxytelechelic oligomers of higher average molecular weight ( 20000 g/mol). New materials are characterized by FTIR/1H-NMR and changes in their Tg according to , are discussed. The influence of reaction time on…
Hydrogels for potential colon drug release by thiol-ene conjugate addition of a new inulin derivative.
2008
Inulin was chosen as a starting polymer for biocompatible, pH-sensitive and biodegradable hydrogels. Three INUDVSA-TT hydrogels were obtained by crosslinking inulin derivatives with trimethylolpropane tris(3-mercaptopropionate) under varying conditions. The resulting hydrogels were cell compatible, as demonstrated by MTS and trypan blue exclusion assays acting on Caco-2 cells, and were biodegraded by inulinase and esterase, thus suggesting their use as colonic drug delivery systems. 2-Methoxyestradiol, an anti-cancer drug, was soaked in INUDVSA-TT hydrogels and its in vitro release and apoptotic effect on Caco-2 cells were evaluated.
Lineare polyester mit carboxylendgruppen und deren bestimmung
1955
Durch Umsetzung von „alkoholischen” Bernsteinsaure-1,6-Hexandiol-Polyestern mit Bernsteinsaureanhydrid in Benzol werden kettenanaloge Polyester mit endstandigen Carboxylgruppen hergestellt. Die Titration dieser Carboxylgruppen ergibt Molgewichte bis ∼ 7 · 103. Mit Phenylisocyanat in indifferenten Losungsmitteln reagieren Polyesterdicarbonsauren unter Kettenverlangerung und Bildung von kettenstandigen Carbonsaureanhydridgruppen. Die Umsetzung der Polyester-dicarbonsauren in Phenylisocyanat ohne Verdunnungsmittel erfolgt kettenanalog unter Bildung von Carboxanilidendgruppen. Durch photometrische Anilinbestimmung nach der Hydrolyse konnen diese Endgruppen quantitativ bestimmt und Molgewichte b…