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191.
Ions binding to solid organic matter was investigated in this study. A simple surface complexation model, the diffuse double-layer model, was used to describe Pb(II), Cd(II), Zn(II), and Ni(II) binding to a lignocellulosic substrate extracted from wheat bran. The lignocellulosic substrate was represented by two acid sites: a low-pH ("carboxylic") site and a high-pH ("phenolic") site, the phenolic-type sites contributing significantly to the binding behavior, even at relatively low pH. By using the previously determined concentrations of sites and acidity constants, the surface complexation model was applied to Pb, Cd, Zn, and Ni binding as a function of pH in a 0.1 M NaNO(3) medium. The model fits were good over a wide range of pH (2相似文献
192.
Banchet-Cadeddu A Hénon E Dauchez M Renault JH Monneaux F Haudrechy A 《Organic & biomolecular chemistry》2011,9(9):3080-3104
Associated with the CD1d protein, KRN 7000, a potent synthetic α-galactosylceramide, is known to activate the invariant NKT immune cells. This stimulation then leads to the production of different cytokines modulating a T(H)1/T(H)2 immune response balance involved in protection against several pathologies such as autoimmune diseases and cancers. Various efforts have been made toward the synthesis of simple and more functionalized analogues in order to selectively induce T(H)1 or T(H)2-type cytokine production. Since the discovery of KRN 7000, structure-activity relationships, crystallographic and modelling studies have pointed to the potential of several GalCer analogues in term of selective bioactivity, and have highlighted interesting elements in order to better understand the recognition and activation mechanisms of immune iNKT cells. By presenting an up-to-date library of analogues, collecting recent breakthroughs done in crystallography and molecular modelling, and relating them to the available biological results, we hope that this review will highlight and help the scientific community in their KRN research. 相似文献
193.
Boyard-Kieken F Dervilly-Pinel G Garcia P Paris AC Popot MA le Bizec B Bonnaire Y 《Journal of separation science》2011,34(24):3493-3501
Growth hormone (GH) is a polypeptide suspected of being used in horse racing to speed up physical performances. Despite scientific advances in the recent years, the control of its administration remains difficult. In order to improve it, a metabolomics study through LC-high resolution mass spectrometry measurements was recently initiated to assess the metabolic perturbations caused by recombinant equine growth hormone administration. Few tens of ions not identified structurally were highlighted as compounds responsible for the modification of metabolic profiling observed in treated animals. This previous work was based on the use of Uptisphere Strategy NEC as the chromatographic column. In parallel, more and more metabolomics studies showed the interest of the use of new chromatographic supports such as hydrophilic interaction chromatography for the analysis of polar compounds. It is in this context that an investigation was conducted on Uptisphere HDO and Luna hydrophilic interaction chromatography stationary phases to generate and process urinary metabolomics fingerprints, which could allow to establish a comparison with Uptisphere Strategy NEC. The chromatographic column the most adapted for the detection of new biomarkers of GH administration has been used to set up a relevant statistical model based on the analysis of more than hundred biological samples. 相似文献
194.
Cherblanc F Lo YP De Gussem E Alcazar-Fuoli L Bignell E He Y Chapman-Rothe N Bultinck P Herrebout WA Brown R Rzepa HS Fuchter MJ 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(42):11868-11875
Isolation and semisynthetic modification of the fungal metabolite chaetocin gave access to a desulfurized analogue of this natural product. Detailed chiroptical studies, comparing experimentally obtained optical rotation values, electronic circular dichroism spectra, and vibrational circular dichroism spectra to computationally simulated ones, reveal the desulfurization of chaetocin to unambiguously proceed with retention of configuration. Consideration of the plausible mechanisms for this process highlighted inconsistencies in the stereochemical assignment of related molecules in the literature. This in turn allowed the stereochemical reassignment of the natural product analogue dethiodehydrogliotoxin. 相似文献
195.