Interaction Between Metal Cations and Anionic Polysaccharides

1981 ◽  
pp. 349-365 ◽  
Author(s):  
G. PASS ◽  
P. W. HALES
Keyword(s):  
Metal Cations ◽  
Anionic Polysaccharides

Adsorption of metal cations on wool carbonising waste. Part 1. Adsorption isotherms

1981 ◽  
Vol 31 (1) ◽  
pp. 597-601 ◽  
Author(s):  
Karim Farag ◽  
Francis Perineau ◽  
Antoine Gaset ◽  
Jacques Molinier
Keyword(s):  
Adsorption Isotherms ◽  
Metal Cations

A Contribution to the Structure Characteristics and Phase Composition of Vanadium-Phosphorus Catalysts Prepared from the VOPO4.xH2O.yH3PO4 Precursor

1992 ◽  
Vol 57 (12) ◽  
pp. 2475-2480 ◽  
Author(s):  
Milan Brutovský ◽  
Štefan Gerej ◽  
Ján Novák ◽  
Lucia Ferdinandyová
Keyword(s):  
Heat Treatment ◽  
Phase Composition ◽  
Ir Spectra ◽  
Metal Cations ◽  
Preparation Procedure ◽  
Final Temperature ◽  
Structure Characteristics ◽  
Heat Treatment Regime ◽  
Condensed Phosphates ◽  
Defective Crystals

Catalysts were prepared from VOPO4.xH2O.yH3PO4 (x = 0.3-2, y = 0.2-0.85) by reduction with SO2 up to a final temperature of 750-800 °C, and activated in a reaction mixture of 1.0-1.4% butane in air up to 500 °C. The structure characteristics and phase composition of the catalysts were found to be affected by the preparation procedure and heat treatment regime. Their diffraction lines and IR spectra revealed that the catalysts from larger and less defective crystals than catalysts which were obtained from the VOHPO4.xH2O.yH3PO4 precursor and activated in the reaction mixture at temperatures up to 500 °C. In the catalysts prepared by the above procedure, the tendency to the formation of phases of higher-condensed phosphates, in particular VO(PO3)2 or even V(PO3)3, increases with increasing n(P):n(V) ratio and is then more pronounced than with vanadium-phosphorus catalysts prepared by other procedures. The tendency to the formation of the catalytically less active condensed phosphates is partly suppressed by the embedding of modifying metal cations (Fe or Cu in this case).

Frequent Occurrence of HIV-Inhibitory Sulphated Polysaccharides in Marine Invertebrates

1993 ◽  
Vol 4 (3) ◽  
pp. 167-172 ◽  
Author(s):  
J. A. Beutler ◽  
T. C. McKee ◽  
R. W. Fuller ◽  
M. Tischler ◽  
J. H. Cardellina ◽  
...  
Keyword(s):  
Marine Invertebrates ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Size Exclusion ◽  
Aqueous Extracts ◽  
Sulphated Polysaccharides ◽  
Anionic Polysaccharides ◽  
Gel Permeation ◽  
Anti Hiv ◽  
C Nmr

Aqueous extracts of many marine invertebrates have exhibited some activity in the National Cancer Institute's primary screen for anti-HIV cytopathicity. Using a variety of techniques, including gel permeation, size exclusion and ion exchange chromatography, toluidine blue metachromicity, 13C-NMR spectroscopy and combustion analyses, we have determined that this activity is largely due to sulphated polysaccharides. Because of the wide occurrence of this class of compounds in these organisms we sought a method for the rapid dereplication of sulphated polysaccharides. It was critical that the method selected for dereplication allow differentiation of anionic polysaccharides from other AIDS-antiviral chemotypes. After evaluating a variety of methods, we found that the most efficient strategy appeared to be precipitation of the polysaccharide fraction from aqueous ethanolic solutions of the crude aqueous extracts.

ChemInform Abstract: Siting and Stability of Metal Cations in Zeolites

ChemInform ◽  
2010 ◽  
Vol 32 (28) ◽  
pp. no-no
Author(s):  
Alexis T. Bell
Keyword(s):  
Metal Cations

scholarly journals The phenoxyl group-modulated interplay of cation–π and σ-type interactions in the alkali metal series

2020 ◽  
Vol 22 (46) ◽  
pp. 27105-27120
Author(s):  
Giacomo Prampolini ◽  
Marco d'Ischia ◽  
Alessandro Ferretti
Keyword(s):  
Alkali Metal ◽  
Noncovalent Interactions ◽  
Metal Cations ◽  
Alkali Metal Cations ◽  
Striking Effect

An extensive exploration of the interaction PESs of phenol and catechol complexes with alkali metal cations reveals a striking effect of –OH substitution on the balance between cation-π and σ-type noncovalent interactions.

scholarly journals Rheology and Water Absorption Properties of Alginate–Soy Protein Composites

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1807
Author(s):  
Estefanía Álvarez-Castillo ◽  
José Manuel Aguilar ◽  
Carlos Bengoechea ◽  
María Luisa López-Castejón ◽  
Antonio Guerrero
Keyword(s):  
Soy Protein ◽  
Water Solubility ◽  
Divalent Cations ◽  
Low Cost ◽  
Soy Protein Isolate ◽  
Protein Isolate ◽  
Guluronic Acid ◽  
Wide Range ◽  
Anionic Polysaccharides ◽  
Porous Matrices

Composite materials based on proteins and carbohydrates normally offer improved water solubility, biodegradability, and biocompatibility, which make them attractive for a wide range of applications. Soy protein isolate (SPI) has shown superabsorbent properties that are useful in fields such as agriculture. Alginate salts (ALG) are linear anionic polysaccharides obtained at a low cost from brown algae, displaying a good enough biocompatibility to be considered for medical applications. As alginates are quite hydrophilic, the exchange of ions from guluronic acid present in its molecular structure with divalent cations, particularly Ca2+, may induce its gelation, which would inhibit its solubilization in water. Both biopolymers SPI and ALG were used to produce composites through injection moulding using glycerol (Gly) as a plasticizer. Different biopolymer/plasticizer ratios were employed, and the SPI/ALG ratio within the biopolymer fraction was also varied. Furthermore, composites were immersed in different CaCl2 solutions to inhibit the amount of soluble matter loss and to enhance the mechanical properties of the resulting porous matrices. The main goal of the present work was the development and characterization of green porous matrices with inhibited solubility thanks to the gelation of alginate.

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