Reactions of ferrous and ferric ions with hydrogen peroxide. Part II.—The ferric ion reaction

1951 ◽  
Vol 47 (0) ◽  
pp. 591-616 ◽  
Author(s):  
W. G. Barb ◽  
J. H. Baxendale ◽  
P. George ◽  
K. R. Hargrave
Keyword(s):  
Hydrogen Peroxide ◽  
Ferric Ion ◽  
Ferric Ions

scholarly journals Blue flower coloration of Corydalis ambigua requires ferric ion and kaempferol glycoside

2021 ◽  
Vol 85 (1) ◽  
pp. 61-68
Author(s):  
Kumi Yoshida ◽  
Takeya Oniduka ◽  
Kin-ichi Oyama ◽  
Tadao Kondo
Keyword(s):  
Emission Spectroscopy ◽  
Atomic Emission ◽  
Early Spring ◽  
Blue Flower ◽  
Ferric Ion ◽  
Ferric Ions ◽  
Kaempferol Glycoside ◽  
Cotton Effects ◽  
Blue Coloration ◽  
Exciton Type

Abstract Corydalis ambigua (Japanese name, Ezoengosaku) flowers bloom with blue to purplish petals in early spring in Hokkaido prefecture. In this study, a mechanism for blue petal coloration by ferric ions and keampferol glycoside was elucidated. Blue petals and cell sap exhibited similar visible (Vis) spectra, with λmax at approximately 600 nm and circular dichroism (CD) with positive exciton-type Cotton effects in the Vis region. Analysis of the organic components of the petals confirmed cyanidin 3-O-sambubioside and kaempferol 3-O-sambubioside as the major flavonoids. Mg, Al, and Fe were detected in petals using atomic emission spectroscopy. Color, Vis absorption, and CD consistent with those of blue petals were reproduced by mixing cyanidin 3-O-sambubioside, kaempferol 3-O-sambubioside, and Fe3+ in a buffered aqueous solution at pH 6.5. Both Fe3+ and flavonol were essential for blue coloration.

Homogeneous oxidation of phenols in aqueous solution with hydrogen peroxide and ferric ions

1997 ◽  
Vol 36 (2-3) ◽  
pp. 151-154 ◽  
Author(s):  
H. Grigoropoulou ◽  
C. Philippopoulos
Keyword(s):  
Hydrogen Peroxide ◽  
Ferrous Sulphate ◽  
Ph Control ◽  
Chemical Oxidation ◽  
Ferric Ions ◽  
Experimental Conditions ◽  
Oxidation Rates ◽  
Homogeneous Oxidation ◽  
Oxidation Of Phenol ◽  
Ferrous Ammonium

The chemical oxidation of phenol and chlorophenols with hydrogen peroxide in the presence of soluble iron can be economically attractive at low oxidant consumption, leading then to intermediates that are more easily biodegradable. The homogeneous oxidation of phenol and chlorophenols in aqueous solutions with hydrogen peroxide is studied at oxidant : phenol ratio of about 4:1 and 16:1 (mol/mol) at various catalyst concentrations, at ambient temperature without pH control. Ferric chloride, ferric and ferrous sulphate and ferrous ammonium sulphate are used as oxidation catalysts. Ferric salts induce higher oxidation rates than ferrous ones and the nature of the anions present does not affect reaction rate. 4-Chlorophenol is found to be most resistant to oxidation and 2,4,6-Trichlorophenol is not attacked by hydrogen peroxide in the presence of ferric ions at the experimental conditions studied.

scholarly journals Divergent roles for ferric ions in the biological activity of amidated and non-amidated gastrins

2004 ◽  
Vol 181 (2) ◽  
pp. 315-325 ◽  
Author(s):  
J Pannequin ◽  
JP Tantiongco ◽  
S Kovac ◽  
A Shulkes ◽  
GS Baldwin
Keyword(s):  
Biological Activity ◽  
Inositol Phosphate ◽  
Peptide Hormone ◽  
Iron Chelator ◽  
Spectroscopic Studies ◽  
Jurkat Cells ◽  
Ferric Ion ◽  
Ferric Ions ◽  
Inositol Phosphate Production ◽  
Stimulation Of

Amidated forms of the peptide hormone gastrin act via the cholecystokinin-2 receptor to stimulate gastric acid secretion, whereas non-amidated forms stimulate colonic mucosal proliferation via a novel, as yet uncharacterised, receptor. Nuclear magnetic resonance (NMR) and fluorescence spectroscopic studies have revealed that glycine-extended gastrin17 bound two ferric ions, and that ferric ion binding was essential for biological activity. We have therefore investigated the role of ferric ions in the biological activity of amidated gastrin17. As with glycine-extended gastrin17, fluorescence quenching experiments indicated that Glu7 Ala and Glu8,9 Ala mutants of amidated gastrin17 each bound only one ferric ion. The affinity of the mutant peptides for the cholecystokinin-2 receptor on transfected COS-7 cells or on Tlymphoblastoid Jurkat cells, and their potency in stimulation of proliferation in Jurkat cells and inositol phosphate production in transfected COS-7 cells, were similar to the values obtained for amidated gastrin17. In addition, the iron chelator desferrioxamine did not significantly inhibit either binding of amidated gastrin17 to the cholecystokinin-2 receptor, or stimulation of inositol phosphate production by amidated gastrin17 in transfected COS-7 cells. We conclude that, in contrast to glycine-extended gastrin17, binding of ferric ions is not essential for the biological activity of amidated gastrin17. Our results support the concept of distinct modes of action for amidated and non-amidated gastrins, and raise the possibility of developing selective antagonists of the actions of non-amidated and amidated gastrins.

scholarly journals Unusual behavior of natural polyphosphates during IMAC

2013 ◽  
Vol 19 (No. 5) ◽  
pp. 161-165
Author(s):  
M. Kmínková ◽  
A. Prošková ◽  
J. Kučera
Keyword(s):  
Phytic Acid ◽  
Iron Content ◽  
Metal Ion ◽  
Ferric Ion ◽  
Ferric Ions ◽  
Unusual Behavior ◽  
Strong Bond ◽  
Hydrolysis Of ◽  
Chelating Groups ◽  
Metal Ion Affinity Chromatography

The atypical course of IDA-ferric (Imino-Di-Acetyl-agarose saturated with ferric ions) of two polyphosphorylated compounds – phytic acid and Ser(P)-Ser(P)-Ser(P)-Glu-Glu cluster obtained by the way of pancreatic hydrolysis of bovine casein was detected. The spectral data (for phytic acid) and iron content (for polyphosphate cluster) indicate the strong bond of ferric ions to these polyphosphorylated compounds. The data shows these compounds to bind ferric ion stronger even in comparison with IDA (Imino-Di-Acetate) itself. Therefore attention is to be paid to all IMAC (Immobilized-Metal-Ion-Affinity-Chromatography) of natural compounds containing strong chelating groups or several chelating groups in vicinity.

Quantum efficiencies of the photo-Fenton degradation of atrazine in water

2012 ◽  
Vol 66 (10) ◽  
pp. 2209-2216 ◽  
Author(s):  
T. B. Benzaquén ◽  
M. A. Isla ◽  
O. M. Alfano
Keyword(s):  
Hydrogen Peroxide ◽  
Organic Carbon ◽  
Ferric Ion ◽  
Fenton Process ◽  
Triazine Ring ◽  
Experimental Conditions ◽  
Maximum Value ◽  
Absolute Quantum ◽  
Atrazine Degradation ◽  
Recycling Reactor

An experimental work in a well-stirred batch recycling reactor for the photo-Fenton degradation of atrazine in water is presented. A study of the quantum efficiency is performed to assess the effectiveness of the photo-Fenton process on the atrazine degradation and total organic carbon (TOC) mineralization. Apparent and absolute quantum efficiencies of degradation and mineralization of an atrazine-based commercial herbicide are determined under different experimental conditions. Higher apparent efficiencies were found for both atrazine degradation and TOC mineralization when the ferric ion and hydrogen peroxide concentrations are increased. Because of the well known stability of the triazine ring, atrazine was not completely mineralized by the photo-Fenton process. However, a TOC reduction of 40% was achieved, being 62.5% of the maximum value that can be reached.

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