Search results for "Flor"

Ternary Polymer Solutions with Hydrogen Bonds, 1

2007

The Flory Huggins methodology coupled to AET has been extended to ternary polymer systems, in particular to solvent (A)/polymer 1 (B)/polymer 2 (C) systems, with the two polymers displaying H-bonding interactions. Because the H-bonding can perturb the randomness of polymeric conformations, the change in Gibbs free energy of mixing, AG, should arise from changes in combinatorial entropy as well as in interaction energy. The combinatorial part of AG is evaluated through AET as a function of the association constant η between B and C components, the autoassociation constant a between B components, and the independent number m of interaction sites of acceptor C. The enthalpic contribution is ev…

Correlation between transport and equilibrium properties through the ternary interaction parameter for cosolvent and cononsolvent polymeric systems

1992

A study of the ternary polymer systems dimethyl formamide-ethyl acetate-polystyrene, chloroform-1,4 dioxane-polystyrene and tetrahydrofuran-chloroform-polystyrene was carried out by viscosity and light scattering at 298 K. A good correlation has been found between the excess intrinsic viscosity, unperturbed polymer dimensions, second virial coefficient and the excess Gibbs free energy by using a ternary interaction parameter, dependent on molecular weight. This modification enables the conversion between transport and equilibrium properties.

Phytochemical analysis of two Weigela florida cultivars, “Pink Poppet” and “Jean’s Gold”

2020

Abstract Nine different oleanane-type glycosides were extracted and isolated by various chromatographic methods from two Weigela florida cultivars, “Pink Poppet” and “Jean’s Gold”. From the roots of W. florida “Pink Poppet”, three monodesmosidic oleanolic acid saponins 1, 4, 5 were obtained, together with one hederagenin ester 6 from the leaves, and six bidesmosidic saponins 2, 3, 6-9 were isolated from the leaves of W. florida “Jean’s Gold”. Among compounds 1-9, three were previously undescribed (1-3) and six (4-9) were already published in the literature. Their structures were assigned by spectroscopic analysis mainly 2D NMR and mass spectrometry (ESI-MS). The cytotoxicity of the isolated…

Improved micropropagation in Polygala myrtifolia

2004

Stem segments from apical shoot tips of Polygala myrtifolia were used as primary explants to establish in vitro cultures. Axillary shoots produced on noncontaminated explants were excised and recultured in the same medium to increase the stock of shoot cultures. Equal molar concentrations of five cytokinins 2-isopentenyladenine (2iP), kinetin, zeatin, N6-benzyladenine (BA) and adenine were tested for ability to induce axillary shoot development from double node stem segments. The highest rate of axillary shoot proliferation was induced on Murashige and Skoog agar medium supplemented with 1.8 M BA. Seven indole-3-acetic acid (IAA) concentrations (2.8, 5.7, 8.6, 11.4, 14.3, 17.1 M) were t…

A266 AMYLASE TRYPSIN INHIBITORS FROM WHEAT EXACERBATE GLUTEN-INDUCED PATHOLOGY AND ALTER GUT MICROBIOTA IN MICE

2018

BACKGROUND: Celiac disease (CeD) is an autoimmune enteropathy triggered by gluten in genetically susceptible individuals expressing HLA DQ2 or DQ8. The adaptive immune response is characterized by a gluten-specific T-cells, anti-gluten and anti-tissue transglutaminase-2 antibodies. Proliferation and activation of intraepithelial lymphocytes (IELs) is central to the innate immune response, although the triggers and receptors remain unclear. Amylase trypsin inhibitors (ATIs) are pest-resistant molecules in modern wheat with TLR4-activating capacities in mononuclear phagocytic cells. AIMS: Our aim was to determine whether ATIs act as innate activators, enhancing gluten immunopathology in mice.…

1990

Taking into account the dependency on molar mass of the viscometric interaction parameter B, the modified Stockmayer-Fixman-Burchard equation ([η]/M1/2) = KΘ + C″ · A2 · M1/2 is obtained. It relates the intrinsic viscosity, [η], to the second virial coefficient, A2, and to the unperturbed dimensions parameter, KΘ, with C″ being a constant. Hereupon, KΘ can be determined from [η] and A2 data of any binary (solvent/polymer) and/or ternary (solvent 1/solvent 2/polymer) system, BPS and/or TPS. Because of the scarcity of reliable sets of [η] and A2 values mostly for TPS, the application of the above equation to obtain KΘ coefficients rests limited. This limitation can be surmounted by an A2 eval…

Glycoside derivatives of scopoletin and β-sitosterol from Hymenodictyon floribundum

2003

Fatty acid composition of the seed lipids ofChamaerops humilisL. natural populations and its relation with the environment

2014

Seed lipids composition is a tool to discriminate among plant taxa and is related to phylogeny and biogeographic distribution. Aim of the present study was to evaluate the fatty acid (FA) composition of the seed lipids from nine natural Chamaerops humilis L. population and its relation with the climatic traits of the collection sites. The average seed lipids content was 54.8 g kg21 and the most represented FAs were oleic (478 g kg21 oil) and linoleic (230 g kg21 oil), with significant differences among the accessions. Most of the lipid traits significantly correlated with climatic traits. In particular, oleic acid negatively correlated with year potential evapotranspiration. These relations…

Omega-3 PUFAs and gut microbiota: A preventive approach for colorectal cancer

2021

The influence of diet on the composition of the intestinal microbiota and related pathologies has been known for some time. Some classes of nutrients, such as fatty acids belonging to the omega 3 series, have particular effects on the bacteria that make up the intestinal microbiota. ω-3 PUFAs affect the gut microbiota in three different ways: by modulating the type and abundance of intestinal bacteria, by regulate SCFAs levels, and by alter the levels of proinflammatory mediators. Through these modalities, ω-3 PUFAs could be useful for the prevention of intestinal diseases such as Colorectal Cancer (CRC). The ability of ω-3 PUFAs to modulate the intestinal inflammatory response, to preserve…

1990

Intrinsic viscosities, [η], second virial coefficients, A2, and interaction potentials, g12, for the ternary systems alcohol (1)/3-heptanone (2)/poly(1-vinyl-2-pyrrolidone) (3), with the unbranched alcohols methanol, ethanol and 1-propanol, were determined at 25°C. Taking into account the dependence of the viscometric interaction parameter, B, with the molecular weight of the polymer, the unperturbed dimensions parameter, KΘ, of the polymer was unambiguously obtained. Relationships between ΔKΘ (defined as ΔKΘ = ΔK − KΘ) and excess Gibbs energies, GE, and between excess viscosity, Δ[η], and GE allow to obtain equations relating A2 to ΔKΘ or to Δ[η]. Therefore, A2 can be evaluated from experi…