Search results for "dextrin"
showing 10 items of 297 documents
CCDC 1531987: Experimental Crystal Structure Determination
2017
Related Article: Spyros D. Chatziefthimiou, Mario Inclán, Petros Giastas, Athanasios Papakyriakou, Konstantina Yannakopoulou and Irene M. Mavridis|2017|Beilstein J.Org.Chem.|13|1572|doi:10.3762/bjoc.13.157
Guest-to-host proton transfer in melatonin-beta-cyclodextrin inclusion complex by ionspray, fast atom bombardment and tandem mass spectrometry.
2001
Ionspray (IS) and fast atom bombardment (FAB) positive ionization mass spectrometry (MS) of 1:1 β-cyclodextrin (β-CD)-melatonin (MLT) host-guest complex allowed the detection of gaseous protonated 1:1 β-CD-MLT. Tandem MS collision-induced dissociation (CID) of such protonated 1:1 β-CD-MLT species showed the proton (charge) to be retained to a significant extent by the host and by its cage fragmentation products, in spite of the higher proton affinity of MLT with respect to that of β-CD. This requires an endothermic guest-to-host proton transfer to occur within the gaseous association. Collisional activation could be accounted for by the promotion of such an endothermic process; however…
Host−Guest Interactions between β-Cyclodextrin and the (Z)-Phenylhydrazone of 3-Benzoyl-5-phenyl-1,2,4-oxadiazole: The First Kinetic Study of a Ring…
2002
The effect of beta-cyclodextrin (beta-CD) on the mononuclear heterocyclic rearrangement of the (Z)-phenylhydrazone of 3-benzoyl-5-phenyl-1,2,4-oxadiazole (1) in aqueous borate buffer at pH = 9.6 has been analyzed at temperatures ranging from 293.15 to 313.15 K. The trend of the absorption spectra of 1 as a function of time has been accounted for with the formation of two different 1:1 complexes between beta-CD and 1, the first, "unreactive" complex being formed faster than the "reactive" one. The occurrence of negative activation enthalpy values for the studied interconversion evidences the kinetic relevance of inclusion processes. Computational models elaborated using the MM2 molecular mec…
Polyester vascular prostheses coated with a cyclodextrin polymer and activated with antibiotics: Cytotoxicity and microbiological evaluation
2008
Abstract Polyester (PET) vascular grafts are used to replace or bypass damaged arteries. To minimize the risk of infection during and after surgical interventions, a PET vascular prosthesis (Polythese®) was functionalized with cyclodextrin polymers (PolyCDs) in order to obtain the controlled release of antibiotics (ABs: ciprofloxacin, vancomcyin and rifampicin). An epithelial cell line (L132) was used to determine the viability of the antibiotics, and human pulmonary microvascular endothelial cells (HPMEC) were used for cell proliferation by cell counting and cell vitality with Alamar Blue fluorescent dye. Staphylococcus aureus, Escherichia coli and Enteroccocus sp. were used to determine t…
Molecular recognition of N-acetyltryptophan enantiomers by β-cyclodextrin
2017
The enantioselectivity of β-cyclodextrin (β-CD) towards L- and D-N-acetyltryptophan (NAcTrp) has been studied in aqueous solution and the crystalline state. NMR studies in solution show that β-CD forms complexes of very similar but not identical geometry with both L- and D-NAcTrp and exhibits stronger binding with L-NAcTrp. In the crystalline state, only β-CD–L-NAcTrp crystallizes readily from aqueous solutions as a dimeric complex (two hosts enclosing two guest molecules). In contrast, crystals of the complex β-CD–D-NAcTrp were never obtained, although numerous conditions were tried. In aqueous solution, the orientation of the guest in both complexes is different than in the β-CD–L-NAcTrp …
Utilisation of pectin coating to enhance spray-dry stability of pea protein-stabilised oil-in-water emulsions
2010
International audience; In this study, development of pea (Pisum sativum) protein stabilised dry and reconstituted emulsions is presented. Dry emulsions were prepared by spray-drying liquid emulsions in a laboratory spray-dryer. The effect of drying on the physical stability of oil-in-water emulsions containing pea protein-coated and pea protein/pectin-coated oil droplets has been studied. Oil-in-water emulsions (5 wt.% Miglyol 812 N, 0.25 wt.% pea protein, 11% maltodextrin, pH 2.4) were prepared that contained 0 (primary emulsion) or 0.2 wt.% pectin (secondary emulsion). The emulsions were then subjected to spray-drying and reconstitution (pH 2.4). The stability of the emulsions to dry pro…
Diacylglycerol-containing oleic acid induces increases in [Ca(2+)](i) via TRPC3/6 channels in human T-cells.
2011
Though most of the studies have focused on the effects of free fatty acids on T-cell activation, fatty acids incorporated into plasma membrane phospholipids may also affect cell signaling via diacylglycerol (DAG), generally produced by phospholipid hydrolysis. In the present study, we have synthesized a DAG-containing oleic acid and studied its implication in the modulation of calcium signaling in human Jurkat T-cells. 1-palmitoyl-2-oleoyl-sn-glycerol (POG) induced a dose-dependent increase in [Ca(2+)](i). This effect was due to the presence of oleic acid at the sn-2 position as no differences were observed between POG and 1-stearoly-2-oleoyl-sn-glycerol (SOG). However, the substitution of …
Translational diffusion coefficients of volatile compounds in various aqueous solutions at low and subzero temperatures.
2005
International audience; Translational diffusion coefficients (D(12)) of volatile compounds were measured in model media with the profile concentration method. The influence of sample temperature (from 25 to -10 degrees C) was studied on translational diffusion in sucrose or maltodextrin solutions at various concentrations. Results show that diffusivity of volatile compounds in sucrose solutions is controlled by temperature, molecule size, and the viscosity of the liquid phase as expected with the Stokes-Einstein equation; moreover, physicochemical interactions between volatile compounds and the medium are determinant for diffusion estimation. At negative temperature, the winding path induce…
Hyaluronan alkyl derivatives-based electrospun membranes for potential guided bone regeneration: Fabrication, characterization and in vitro osteoindu…
2020
Item does not contain fulltext The aim of the work was to determine the effects of the chemical functionalization of hyaluronic acid (HA) with pendant aliphatic tails at different lengths and free amino groups in terms of chemical reactivity, degradation rate, drug-eluting features, and surface properties when processed as electrospun membranes (EM) evaluating the osteoinductive potential for a possible application as guided bone regeneration (GBR). To this end, a series of HA derivatives with different aliphatic tails (DD-Cx mol% ≈ 12.0 mol%) and decreasing derivatization of free amino groups (DD(EDA) mol% from 70.0 to 30.0 mol%) were first synthesized, namely Hn. Then dexamethasone-loaded…
Inclusion complexes of cyclomaltooligosaccharides (cyclodextrins) with melatonin in solid phase
2005
Fourier transform infrared spectrometry (FT-IR) and X-Ray diffraction (XRD) investigations were carried out on MLT plus α-, β- and γ-CD physical mixtures and lyophilized or crystalline MLT/α-, β-, γ-CD complexes. Inclusion complexes formation between MLT and cyclodextrins in solid phase has been emphasized by the significant differences between IR and XRD spectra of physical mixtures with respect to those of the complexes. The structure of MLT CDs complexes in the solid state as well as the biochemical and pharmaceutical implications are discussed.