ISSN:0570-0833    

DOI:10.1002/anie.199512611

出版商:Hüthig&Wepf Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractSupercritical fluids are beginning to be used widely in chemistry. Applications range from extraction and chromatography in analytical chemistry to solvents for reaction chemistry and preparation of new materials. Spectroscopic monitoring is important in much of supercritical chemistry, and vibrational spectroscopy is particularly useful in this context because the vibrational spectrum of a given molecule is usually quite sensitive to the environment of that molecule. Thus, vibrational spectra are excellent probes of conditions within the fluid. In this review, we describe a variety of techniques and cells for IR and Raman spectroscopy in supercritical fluids and illustrate the breadth of applications in supercritical fluids. The examples include: the use of supercritical Xe as a spectroscopically transparent solvent for chemistry and for supercritical fluid chromatography with FTIR detection of analytes; Raman spectroscopy as a monitor for gases dissolved in supercritical CO2; the effect of solvent density on hydrogen bonding in supercritical fluids and the formation of reverse micelles; IR as a monitor for the supercritical impregnation/extraction of polymers and the reactions of organometallic compounds impreganated into polymers; reactions of organometallic compounds in supercritical fluids; and finally, the use of miniature flow reactors for laboratory‐scale preparative chemistry. Overall, our aim is to provide a starting point from which individual readers can judge whether such measurements might usefully be applied to their own particular problem

ISSN:0570-0833    

DOI:10.1002/anie.199512751

出版商:Hüthig&Wepf Verlag    

年代:1995

数据来源: WILEY

摘要:

AbstractInvestigation of receptor—ligand interactions remains an inexhaustible challenge for chemists and biologists. Structural exploration of biological receptors is the starting point for a better understanding of how they function. Photoaffinity labeling is a biochemical approach to identify and characterize receptors targeting further structural investigations. The primary structure of a receptor protein was typically obtained by reverse genetics after exhaustive purification and sequencing of the N‐terminal peptide, which allowed the design of the corresponding oligonucleotide probes. Synthesis of these oligonucleotide probes then led to identification of cDNA clones by hybridization. Following this strategy, several membrane neurotransmitter receptors and constituent polypeptides, present in very small quantities in the central nervous system, were identified and their sequence deduced from the cDNA sequence. Since photoaffinity labeling implies the formation of a covalent bond between a radiolabeled ligand analogue and a receptor binding site, it becomes theoretically possible to isolate and sequence radiolabeled peptides and then synthesize the corresponding oligonucleotide probes. Photoaffinity labeling might avoid the critical solubilization and purification steps of the classical approach. To our knowledge, no such example of primary structure determination based on photoaffinity labeling experiments has been reported. However, the extraordinary developments in gene cloning technologies, in particular homology cloning and expression cloning, have made this approach obsolete and raised the question of new perspectives for photoaffinity labeling technology. In this article we present an update on selected original developments, as well as new challenges for this method. Photoaffinity labeling not only gives access to structural elements but is also a potential tool for the investigation of functional aspects of biological receptors, for example their role in signal transduction mechani

ISSN:0570-0833    

DOI:10.1002/anie.199512961

出版商:Hüthig&Wepf Verlag    

年代:1995

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.199513131

出版商:Hüthig&Wepf Verlag    

年代:1995

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.199513161

出版商:Hüthig&Wepf Verlag    

年代:1995

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.199513191

出版商:Hüthig&Wepf Verlag    

年代:1995

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.199513211

出版商:Hüthig&Wepf Verlag    

年代:1995

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.199513231

出版商:Hüthig&Wepf Verlag    

年代:1995

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.199513251

出版商:Hüthig&Wepf Verlag    

年代:1995

数据来源: WILEY

ISSN:0570-0833    

DOI:10.1002/anie.199513281

出版商:Hüthig&Wepf Verlag    

年代:1995

数据来源: WILEY