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1.
Carbohydr Polym ; 238: 116199, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32299569

RESUMO

Octenyl-succinylated inulins (OSA-inulin) were synthesized in aqueous solutions using inulin with varying degrees of polymerization (DP). They were characterized using 1H NMR and FTIR and their degrees of substitution were determined. All the samples formed micellar aggregates in aqueous solution above a critical aggregation concentration (CAC) and solubilized beta-carotene. The amount of beta carotene solubilized within the micelles ranged from 12 to 25 mg/g of OSA-inulin and depended on the inulin molar mass. Dynamic light scattering showed that the aggregates, with and without dissolved beta-carotene, were ∼10-15 nm in size and this was confirmed by Transmission Electron Microscopy which also indicated that the micelles had a globular shape. OSA-inulin particles containing encapsulated beta-carotene were produced by freeze-drying. The encapsulated beta-carotene was not released from the freeze-dried particles when introduced into simulated gastric fluid at pH 2.5 but was readily released in simulated small intestinal fluid at pH 7. The results demonstrate the potential application of OSA-inulin in the encapsulation, dissolution and targeted delivery of hydrophobic drug molecules for nutraceutical, pharmaceutical and medical applications.


Assuntos
Preparações de Ação Retardada , Portadores de Fármacos , Inulina/química , Amido/análogos & derivados , Preparações de Ação Retardada/síntese química , Preparações de Ação Retardada/química , Portadores de Fármacos/síntese química , Portadores de Fármacos/química , Micelas , Amido/síntese química , Amido/química , beta Caroteno
2.
Data Brief ; 28: 104861, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31872000

RESUMO

The data presented in this manuscript presents the characterisation spectra of three hyperbranched polymers as discussed in the paper "Folic Acid and Rhodamine Labelled pH Responsive Hyperbranched Polymers: synthesis, characterisation and cell uptake studies" [1]. Characterisation of polymers was performed via 1H Nuclear Magnetic Resonance (1H NMR) and Size Exclusion Chromatography (SEC). pH responsive characteristics were observed via Dynamic Light Scattering (DLS). The data for characterisation of folate conjugated hyperbranched polymer is presented as 1H NMR, Ultra Violet Visible (UV-VIS) spectra and DLS measurements. Further data is presented detailing the experiments for the synthesis of monomers 2-propyl acrylic acid (PAA) and disulfide diacrylate (DSDA), with the full synthesis of folic acid-poly (ethylene glycol) (PEG) linker, rhodamine B ethylenediamine linker and bioconjugation reactions also detailed.

3.
Nanomaterials (Basel) ; 8(12)2018 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-30518035

RESUMO

The present study reports a green and sustainable method for the synthesis of titanium dioxide (TiO2) nanoparticles (NPs) from titanium oxysulfate solution using Kondagogu gum (Cochlospermum gossypium), a carbohydrate polymer, as the NPs formation agent. The synthesized TiO2 NPs were categorized by techniques such as X-Ray Diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy analysis, Raman spectroscopy, scanning electron microscope- Energy-dispersive X-ray spectroscopy (SEM-EDX), Transmission electron microscopy (TEM), High-resolution transmission electron microscopy (HR-TEM), UV-visible spectroscopy, Brunauer-Emmett-Teller (BET) surface area and particle size analysis. Additionally, the photocatalytic actions of TiO2 NPs were assessed with regard to their ability to degrade an organic dye (methylene blue) from aqueous solution in the presence of solar light. Various parameters affecting the photocatalytic activity of the TiO2 NPs were examined, including catalyst loading, reaction time, pH value and calcination temperature of the aforementioned particles. This green synthesis method involving TiO2 NPs explores the advantages of inexpensive and non-toxic precursors, the TiO2 NPs themselves exhibiting excellent photocatalytic activity against dye molecules.

4.
Int J Biol Macromol ; 101: 904-909, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28359894

RESUMO

This study reports on the chemical and physicochemical properties of the polysaccharide isolated from Bauhinia monandra seeds. The seeds were found to contain 17.8% polysaccharide which consisted predominantly of galactose and mannose. The Man/Gal ratio was found to be approximately 4:1and the average molar mass was 2.54×105g/mol. The extracted material was also found to contain a small amount of protein (5.35%). The galactomannan produced highly viscous solution; the viscosity-shear rate profile was best described by the Williamson model. The mechanical spectrum of a 0.5wt% solution showed that G″ was greater than G' over the frequency range employed while at higher concentrations G' became greater than G″ above a critical frequency. The solutions obeyed the Cox-Merz rule at low concentrations, but there was some deviation at higher concentrations. Viscosity measurements were undertaken over a range of temperatures and the activation energy of viscous flow was found to be 20.75kJ/mol. The rheological properties of solutions of B. monandra galactomannan indicate that it has comparable characteristics to other commercially important galactomannans such as guar gum and locust bean gum and hence has potential as a thickener in the formulation of food and other related products.


Assuntos
Bauhinia/química , Mananas/química , Sementes/química , Elasticidade , Galactanos/química , Galactose/análogos & derivados , Indústrias , Monossacarídeos/análise , Gomas Vegetais/química , Soluções , Temperatura , Viscosidade
5.
Int J Biol Macromol ; 91: 299-309, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27212218

RESUMO

Nanofibers of natural tree polysaccharides based on three gums namely Arabic (GA), karaya (GK) and kondagogu (KG) have been prepared for the first time using electrospinning. Electrospinning solutions were prepared by mixing gum solutions of GA, GK & KG with eco-friendly polymers such as polyvinyl alcohol (PVA) or polyethylene oxide (PEO). The present study focuses on the effect of electrospinning blended solutions of GA, GK or KG with PVA or PEO, additives which influence system parameters and process parameters. This has important effects on the electrospinning process and the resulting fibers whose morphology and physicochemical properties were evaluated. The mass ratios of 70:30 to 90:10 for PVA: GA, PVA: GK and PVA: KG were observed to establish an optimum blend solution ratio in order to fabricate uniform beadless nanofibers with an average diameter of 240±50, 220±40 and 210±30nm, respectively. Various structural and physicochemical properties of the electrospun fibers were investigated. Furthermore, the comparisons of various functionalities of the untreated and plasma treated electrospun fibers were assessed. The methane plasma treated nanofibers were shown to be of extremely specific surface area, improved water contact angle, high surface porosity and roughness and superior hydrophobic properties compared to untreated fibers.


Assuntos
Goma Arábica/química , Goma de Karaya/química , Nanofibras/química , Nanofibras/ultraestrutura , Gases em Plasma/química
6.
J Agric Food Chem ; 63(14): 3757-65, 2015 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-25797306

RESUMO

Esterifications of the tree-based gum, gum karaya (GK), using dodecenylsuccinic anhydride (DDSA) were carried out in aqueous solutions. GK was deacetylated using alkali treatment to obtain deacetylated gum karaya (DGK). The DGK and its DDSA derivative were characterized using gel permeation chromatography/multiangle laser light scattering (GPC/MALLS), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), proton nuclear magnetic resonance spectroscopy ((1)H NMR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) analysis, and rheological studies. The degree of substitution was found to be 10.25% for DGK using (1)H NMR spectroscopy. The critical aggregation concentration of DDSA-DGK was determined using dye solubilization and surface tension methods. The antibacterial activity of the DDSA-DGK derivative was then investigated against Gram-negative Escherichia coli and Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus. The DDSA-DGK derivative has the potential for use as a stabilizing agent in food and nonfood applications. It can also be developed as an antibacterial agent.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Goma de Karaya/química , Goma de Karaya/farmacologia , Sterculia/química , Antibacterianos/isolamento & purificação , Bactérias/efeitos dos fármacos , Goma de Karaya/isolamento & purificação , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Anidridos Succínicos/química
7.
J Agric Food Chem ; 57(19): 9154-9, 2009 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-19757813

RESUMO

The impact of ultraviolet (UV) irradiation on the physicochemical and functional properties of gum arabic was investigated. Gum arabic samples were exposed to UV irradiation for 30, 60, 90, and 120 min; gum arabic was also treated with formaldehyde for comparison. Molecular weight analysis using gel permeation chromatography indicated that no significant changes occurred on the molecular structure on the samples exposed to UV irradiation. Free amino group analysis indicated that mild UV irradiation (30 min) could induce cross-linking on gum arabic; this result was comparable with that of samples treated with formaldehyde. However, viscosity break down was observed for samples exposed to UV irradiation for longer times (90 and 120 min). All irradiated and formaldehyde-treated samples exhibited better emulsification properties than unirradiated samples. These results indicate that UV-irradiated gum arabic could be a better emulsifier than the native (unmodified) gum arabic and could be exploited commercially.


Assuntos
Goma Arábica/química , Goma Arábica/efeitos da radiação , Raios Ultravioleta , Aminoácidos/análise , Fenômenos Químicos , Reagentes de Ligações Cruzadas , Emulsificantes/química , Formaldeído/farmacologia , Peso Molecular , Reologia , Viscosidade
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