Binding

maather's picture

Determination of Adsorption and Speciation of Chromium Species by Saltbush (Atriplex ‎Canescens) Biomass using a Combination of Xas and Icp–Oes

Journal Title, Volume, Page: 
Microchemical Journal Volume 81, Issue 1, Pages 122–132
Year of Publication: 
2005
Authors: 
Maather F. Sawalha
Environmental Science and Engineering PhD Program, The University of Texas at El Paso, 500 West University Avenue, El Paso, TX 79968-0513, USA
Current Affiliation: 
Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine
J.L. Gardea-Torresdey
Environmental Science and Engineering PhD Program, The University of Texas at El Paso, 500 West University Avenue, El Paso, TX 79968-0513, USA
J.G. Parsons
Department of Chemistry, The University of Texas at El Paso, 500 West University Avenue, El Paso, TX 79968-0513, USA
Geoffrey Saupe
Department of Chemistry, The University of Texas at El Paso, 500 West University Avenue, El Paso, TX 79968-0513, USA
J.R. Peralta-Videa
Department of Chemistry, The University of Texas at El Paso, 500 West University Avenue, El Paso, TX 79968-0513, USA
Preferred Abstract (Original): 

Studies were performed to determine the effect of pH on chromium (Cr) binding by native, esterified, and hydrolyzed saltbush (Atriplex canescens) biomass. In addition, X-ray absorption spectroscopy studies were performed to determine the oxidation state of Cr atoms bound to the biomass. The amounts of Cr adsorbed by saltbush biomass were determined by inductively coupled plasma–optical emission spectroscopy (ICP–OES). For Cr(III), the results showed that the percentages bound by native stems, leaves, and flowers at pH 4.0 were 98%, 97%, and 91%, respectively. On the other hand, the Cr(VI) binding by the three tissues of the native and hydrolyzed saltbush biomass decreased as pH increased. At pH 2.0 the stems, leaves, and flowers of native biomass bound 31%, 49%, and 46%, of Cr(VI), respectively. The results of the XAS experiments showed that Cr(VI) was reduced in some extend to Cr(III) by saltbush biomass at both pH 2.0 and pH 5.0. The XANES analysis of the Cr(III) reaction with the saltbush biomass parts showed an octahedral arrangement of oxygen atoms around the central Cr(III) atom. The EXAFS studies of saltbush plant samples confirmed these results.

2384's picture

‎1,3-Dipropyl-8-(1-phenylacetamide-1H-pyrazol-3-yl)-xanthine ‎Derivatives as Highly Potent and Selective Human A(2B) ‎Adenosine Receptor Antagonists

Journal Title, Volume, Page: 
Bioorg Med Chem.;16(5):2419-30. Epub 2007 Nov 28.
Year of Publication: 
2008
Authors: 
Abdel Naser Zaid
College of Pharmacy, An-Najah National University, Nablus, Palestine
Current Affiliation: 
Department of Pharmacy, Faculty of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine
Mojgan Aghazadeh Tabrizi
Dipartimento di Scienze Farmaceutiche, Università di Ferrara, Via Fossato di Mortara 17-19, 44100 Ferrara, Italy
Pier Giovanni Baraldi
Dipartimento di Scienze Farmaceutiche, Università di Ferrara, Via Fossato di Mortara 17-19, 44100 Ferrara, Italy
Delia Preti
Dipartimento di Scienze Farmaceutiche, Università di Ferrara, Via Fossato di Mortara 17-19, 44100 Ferrara, Italy
Romeo Romagnoli
Dipartimento di Scienze Farmaceutiche, Università di Ferrara, Via Fossato di Mortara 17-19, 44100 Ferrara, Italy
Giulia Saponaro
Dipartimento di Scienze Farmaceutiche, Università di Ferrara, Via Fossato di Mortara 17-19, 44100 Ferrara, Italy
Stefania Baraldi
Dipartimento di Scienze Farmaceutiche, Università di Ferrara, Via Fossato di Mortara 17-19, 44100 Ferrara, Italy
Allan R. Moorman
King Pharmaceuticals, Inc., Research and Development, 4000 CentreGreen Way, Suite 300, Cary, North Carolina 27513, Italy
Katia Varani
Dipartimento di Medicina Clinica e Sperimentale-Sezione di Farmacologia, Università di Ferrara, 44100 Ferrara, Italy
Pier Andrea Borea
Dipartimento di Medicina Clinica e Sperimentale-Sezione di Farmacologia, Università di Ferrara, 44100 Ferrara, Italy
Preferred Abstract (Original): 

A new series of 1,3-dipropyl-8-(1-phenylacetamide-1H-pyrazol-3-yl)-xanthine derivatives has been identified as potent A(2B) adenosine receptor antagonists. The products have been evaluated for their binding affinities for the human A(2B), A(1), A(2A), and A(3) adenosine receptors. N-(4-chloro-phenyl)-2-[3-(2,6-dioxo-1,3-dipropyl-2,3,6,7-tetrahydro-1H-purin-8-yl)-5-methyl-pyrazol-1-yl] (11c) showed a high affinity for the human A(2B) adenosine receptor K(i)=7nM and good selectivity (A(1), A(2A), A(3)/A(2B)>140). Synthesis and SAR of this novel class of compounds is presented herein.

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