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CM Silva MF Duarte ML Mira MH Florêncio K Versluis AJ Heck 《Rapid communications in mass spectrometry : RCM》1999,13(12):1098-1103
Fast atom bombardment, combined with high-energy collision-induced tandem mass spectrometry, has been used to investigate gas-phase metal-ion interactions with captopril, enalaprilat and lisinopril, all angiotensin-converting enzyme inhibitors.Suggestions for the location of metal-binding sites are presented. For captopril, metal binding occurs most likely at both the sulphur and the nitrogen atom. For enalaprilat and lisinopril, binding preferably occurs at the amine nitrogen. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
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Langhals H Esterbauer AJ Walter A Riedle E Pugliesi I 《Journal of the American Chemical Society》2010,132(47):16777-16782
We investigate the ultrafast resonant energy transfer of a perylene bisimide dyad by pump-probe spectroscopy, chemical variation, and calculations. This dyad undergoes transfer with near-unit quantum efficiency, although the transition dipole moments of the donor and acceptor are in a perfectly orthogonal arrangement to each other in the equilibrium geometry. According to the point dipole approximation used in Fo?rster theory, no energy transfer should occur. Experimentally we do, however, find an ultrafast transfer time of 9.4 ps. With the transition density cube approach we show that in the orthogonal arrangement the Coulombic interactions do not contribute to the electronic coupling. Through the change of the spacer in both length and chemical character, we can clearly exclude any Dexter-type energy transfer. The temperature effects on the Fo?rster resonant energy transfer rate demonstrate that energy transfer is enabled through low-frequency ground-state vibrations, which break the orthogonal arrangement of the transition dipole moments. The dyads presented here therefore are a first example that shows with extreme clarity the decisive role vibrational motion plays in energy transfer processes. 相似文献
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A. Werner T. Grune W. Siems W. Schneider H. Shimasaki H. Esterbauer G. Gerber 《Chromatographia》1989,28(1-2):65-68
Summary The analysis of two metabolite groups, nucleotides and aldehydes, is necessary for assessment of oxygen radical metabolism during hypoxia and reoxygenation.Nucleotides and their derivatives were determined by HPLC using gradient elution with 10 mM NH4H2PO4 buffer containing 2 mM t-butylammoniumphosphate and acetonitrile.Aldehydes occuring after lipid peroxidation were analyzed by derivatisation to dinitrophenylhydrazones followed by TLC and HPLC separation with methanol/water on an ODS column. 相似文献
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Zusammenfassung Eine einfache Synthese für 4-Hydroxy-2-alkenale wird beschrieben. Gesätt. Aldehyde werden bie tiefer Temp. mit Propargylaldehyd-diäthylacetal-magnesiumbromid zu den entsprechenden 4-Hydroxyalkynal-diäthylacetalen umgesetzt. Die Dreifachbindung wird mit LiAlH4 zurtrans-Doppelbindung hydriert. Die 4-Hydroxy-2-alkenaldiäthylacetale werden mit verd. Citronensäure zu den 4-Hydroxy-2-alkenalen verseift. 相似文献