Cyclic voltammetry of water-soluble manganese porphyrins in the presence of cyclodextrins

2005 ◽  
Vol 09 (05) ◽  
pp. 368-376 ◽  
Author(s):  
Oscar Ramirez-Gutierrez ◽  
Josep Claret ◽  
Josep M. Ribo
Keyword(s):  
Cyclic Voltammetry ◽  
Aqueous Solutions ◽  
Inclusion Complexes ◽  
Electrode Surface ◽  
Water Soluble ◽  
Manganese Porphyrins ◽  
Mn Porphyrins

The addition of cyclodextrins (α-CD, β-CD, 2-hydroxopropyl-β-CD and γ-CD) to aqueous solutions of representative cationic ( MnTMPyP ) and anionic ( MnTPPS 4) water-soluble Mn porphyrins only substantially affect the behavior of the Mn (III)/ Mn (II) couple when inclusion complexes (i.e. for MnTPPS 4) are formed. The voltammetric responses were interpreted under the assumption that the inclusion complexes are electroactive, which occurs after their adsorption on the electrode surface. In addition, the results point to a higher affinity of the cyclodextrins for Mn II TPPS 4 than for Mn III TPPS 4.

Oxidation states of manganese porphyrins in water solutions

2005 ◽  
Vol 09 (06) ◽  
pp. 436-443 ◽  
Author(s):  
Oscar Ramirez-Gutierrez ◽  
Josep Claret ◽  
Josep M. Ribo
Keyword(s):  
Oxidation State ◽  
Water Soluble ◽  
Oxidation States ◽  
Vitreous Carbon ◽  
Alkaline Solutions ◽  
Carbon Electrode ◽  
Water Solutions ◽  
Manganese Porphyrins ◽  
Electron Reduction ◽  
Mn Porphyrins

The Mn oxidation state of two water soluble Mn porphyrins, MnTMPyP and MnTPPS 4, was studied as a function of the aqua or hydroxo ligands of the Mn atom. In NaOH solutions, long-lived O = Mn(IV) species were detected in the presence of O 2. Conversely, the dihydroxo Mn(III) porphyrin reduces spontaneously to the Mn(II) species in the absence of O 2. In alkaline solutions, these Mn porphyrins were able to electrocatalyze the 4-electron reduction of O 2 to H 2 O on a vitreous carbon electrode.

THE SOLUBLE PROTEINS OF THE MUSCLE TISSUE OF THE HADDOCK

1931 ◽  
Vol 6 (1) ◽  
pp. 1-11 ◽  
Author(s):  
J. F. LOGAN
Keyword(s):  
Sodium Chloride ◽  
Aqueous Solutions ◽  
Muscle Tissue ◽  
Soluble Protein ◽  
Potassium Phosphate ◽  
Extraction Methods ◽  
Water Soluble ◽  
Tabular Form ◽  
Water Soluble Protein ◽  
Isoelectric Points

As a contribution to the chemistry of muscle tissue, the solubility of the protein of haddock muscle in aqueous solutions of sodium chloride and neutral potassium phosphate, respectively, was determined. The results are expressed in tabular form and graphically in the form of solubility curves. A water-soluble protein and also a salt-soluble protein were isolated from dialyzed haddock muscle by extraction methods. These proteins were obtained in a comparatively pure condition by precipitation from solution in the region of their isoelectric points.

Application of a synthetic water-soluble poly( N -maleyl glycine- co -acrylamide) as polychelatogen for inorganic ions in aqueous solutions

1998 ◽  
Vol 41 (6) ◽  
pp. 687-694 ◽  
Author(s):  
G. del C. Pizarro ◽  
O. G. Marambio ◽  
B. L. Rivas ◽  
K. E. Geckeler
Keyword(s):  
Aqueous Solutions ◽  
Inorganic Ions ◽  
Water Soluble ◽  
Soluble Poly ◽  
Synthetic Water

THE WATER-SOLUBLE POLYSACCHARIDES OF DERMATOPHYTES: IV. GALACTOMANNANS I FROM TRICHOPHYTON GRANULOSUM, TRICHOPHYTON INTERDIGITALE, MICROSPORUM QUINCKEANUM, TRICHOPHYTON RUBRUM, AND TRICHOPHYTON SCHÖNLEINII

1965 ◽  
Vol 43 (1) ◽  
pp. 30-39 ◽  
Author(s):  
C. T. Bishop ◽  
M. B. Perry ◽  
F. Blank ◽  
F. P. Cooper
Keyword(s):  
Aqueous Solutions ◽  
Copper Complexes ◽  
Trichophyton Rubrum ◽  
Periodate Oxidation ◽  
Structural Features ◽  
Water Soluble ◽  
Major Constituent ◽  
Branch Points ◽  
Terminal Units ◽  
Hydrolysis Of

A group of polysaccharides, called galactomannans I, were precipitated as their insoluble copper complexes from aqueous solutions of the crude polysaccharides obtained from each of the organisms designated in the title. The five galactomannans I were homogeneous under conditions of electrophoresis and ultracentrifugation and had high positive specific rotations. The major constituent monosaccharide was D-mannose; amounts of D-galactose ranged from nil for the polysaccharide from T. rubrum to 13% for that from T. schönleinii. Methylation and hydrolysis of the five galactomannans I yielded varying amounts of the following: 2,3,5,6-tetra-O-methyl-D-galactose (not present in the products from T. rubrum), 2,3,4,6-tetra-O-methyl-D-mannose, 2,3,4-tri-O-methyl-D-mannose, 2,4,6-tri-O-methyl-D-mannose, 3,4-di-O-methyl-D-mannose, and 3,5-di-O-methyl-D-mannose. Periodate oxidation results agreed with the methylation studies. The gross structural features of each galactomannan I appear to be the same, namely, a basic chain of 1 → 6 linked α-D-mannopyranose units for approximately every 22 of which there is a 1 → 3 linked α-D-mannopyranose residue. Branch points occur along the 1 → 6 linked chain at the C2 positions of the D-mannopyranose units and once in every 45 units at the C2 position of a 1 → 6 linked D-mannofuranose residue. The D-galactose in the polysaccharides is present exclusively as non-reducing terminal furanose units; non-reducing terminal units of D-mannopyranose are also present. The variations in the identities and relative amounts of the non-reducing terminal units were the only apparent differences in the gross structural features within this group of polysaccharides.

Decoloration of Azo Dyes by Hydrogen Peroxide Catalyzed by Water-Soluble Manganese Porphyrins

1999 ◽  
Vol 69 (12) ◽  
pp. 956-960 ◽  
Author(s):  
J. Tokuda ◽  
R. Ohura ◽  
T. Iwasaki ◽  
Y. Takeuchi ◽  
A. Kashiwada ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Azo Dyes ◽  
Water Soluble ◽  
Manganese Porphyrins

scholarly journals Interactions between 4-thiothymidine and water-soluble cyclodextrins: Evidence for supramolecular structures in aqueous solutions

2016 ◽  
Vol 12 ◽  
pp. 549-563 ◽  
Author(s):  
Vito Rizzi ◽  
Sergio Matera ◽  
Paola Semeraro ◽  
Paola Fini ◽  
Pinalysa Cosma
Keyword(s):  
Inclusion Complexes ◽  
Pyrimidine Ring ◽  
Protective Role ◽  
Supramolecular Structures ◽  
Water Soluble ◽  
Aqueous Environment ◽  
Spectroscopic Techniques ◽  
Guest Molecules ◽  
H Nmr ◽  
Cv Measurements

Since several years the inclusion of organic compounds (guests) within the hydrophobic cavity (host) of cyclodextrins (CDs) has been the subject of many investigations. Interestingly, the formation of inclusion complexes could affect the properties of the guest molecules and, for example, the influence of the delivery system can be a method to improve/change the photochemical behavior of the guest. In particular, very recent studies have shown the protective role of CDs preventing the degradation of the encapsulated guest. Starting from this consideration, in this work, only the structure and complexation mode of the inclusion complexes involving 4-thiothymidine (S4TdR, a known photosensitizer) and five CDs, namely 2-hydroxypropyl-α-cyclodextrin (2-HP-α-CD), 2-hydroxypropyl-β-cyclodextrin (2-HP-β-CD), 2-hydroxypropyl-γ-cyclodextrin (2-HP-γ-CD), heptakis-(2,6-di-O-methyl)-β-cyclodextrin (DIMEB CD) and heptakis-(2,3,6-tri-O-methyl)-β-cyclodextrin (TRIMEB CD) were investigated by different spectroscopic techniques (UV–vis, FTIR–ATR, 1H NMR) and cyclic voltammetry analysis (CV). This work is necessary for a prospective research on the photoreactivity of S4TdR in aqueous environment and in the presence of CDs to prevent its degradation under irradiation. UV–vis, FTIR–ATR and CV measurements suggested the formation of supramolecular structures involving the employed CDs and mainly the pyrimidine ring of S4TdR. 1H NMR analyses confirmed such indication, unveiling the presence of inclusion complexes. The strongest and deepest interactions were suggested when TRIMEB and DIMEB CDs were studied. The S4TdR affinity towards CDs was also evaluated by using the Benesi–Hildebrand (B–H) equation at 25 °C employing CV and 1H NMR methods. The stoichiometry of the interaction was also inferred and it appears to be 1:1 for all examined CDs.

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