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Volume 54, Issue 5
Displaying 1-12 of 12 articles from this issue
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Developmentand Characteristics of Chiral Staionary Phases Consist of Polysaccharide Derivatives and Application to Large Scale SeparationAtsushi OHNISHI, Akito ICHIDA, Shigeo MAKINO1996 Volume 54 Issue 5 Pages 344-353
Published: May 01, 1996
Released on J-STAGE: January 28, 2010
JOURNAL FREE ACCESSThe importance of optically active compounds for pharmaceutical usages has increased. High-performance liquid chromatographic (HPLC) resolution on chiral stationary phases (CSPs) is useful for the analysis of the compounds as well the sample preparations to estimate in the developing stages. CSPs consisting of polysaccharide derviatives were developed by adsorbing them on silica gel on the basis of information obtained from cellulose triacetate. The characteristics of cellulosic esters (OA, OB, OJ, OK) and carbamtes (OC, OF, OG, OD), and amylosic carbamtes (AS, AD) in chiral recognition were introduced with many examples. The optimization of sepqrating conditions are discussed in mentioning the differences among the acidic, neutral or basic compounds. Furthermore, we introduced the principle and applications on the Simulated Moving Bed process to produce optically active compounds in the industrial scale as one of the HPLC methods.View full abstractDownload PDF (1223K) -
Jun UZAWA, Hiroyuki KOSHINO1996 Volume 54 Issue 5 Pages 354-366
Published: May 01, 1996
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSIn the 50 years history of the high resolution NMR, FT-NMR, 2D-NMR and Pulsed Field Gradient (PFG) techniques are the most successful in the chemistry and biochemistry. In this review, the topics of the NMR techniques using PFG, including principle of PFG, pulse sequences, selection of coherence-transfer pathway and the application in chemistry with some 2D NMR spectra are presented. Several inverse techniques especially HMBC (Heteronuclear Multiple-Bond Correlation) spectroscopy are drastically improved by PFG. Spectral data of 1H-13C PFG-HMBC, 1H-15N PFG-HMBC, and 1H-29Si PFG-HMBC are shown and merits of those techniques are discussed. New pulse techniques, PFG- INADEQUATE, 1 D and 2D selective experiments such as GOESY and 2D-selective PFG-TOCSY-HMQC-COSY are also introduced. These new PFG NMR techniques to analyze structures or mechanism of reactions may be powerful and useful methods for synthetic organic chemists.View full abstractDownload PDF (1880K) -
Hiromichi KUROSU, Isao ANDO1996 Volume 54 Issue 5 Pages 367-374
Published: May 01, 1996
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSThe application of high-resolution solid-state NMR spectroscopy to structural and dynamical analyses of solid peptides, polypeptides, calixalene, conductive polymers, polyesters and poly (ethylene oxide) in the solid state have been introduced. It has been demonstrated that the high-resolution solid-state NMR spectroscopy is a very powerful means for elucidating the structure and dynamics of molecules in the solid state.View full abstractDownload PDF (911K) -
Tomoya KINUMI, Masayuki KUBOTA, Mamoru OHASHI1996 Volume 54 Issue 5 Pages 375-383
Published: May 01, 1996
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSThis review describes modern mass spectrometric techniques which make it possible to apply to highly polar and large biomolecules. In recent years, the use of mass spectrometry has dramatically expanded in biochemical and medical fields.
Significant developments in these techniques have been established by ESI/MS (electrospray ionization mass spectrometry) and MALDI-TOF/MS (matrix-assisted laser desorption ionization time-of-flight mass spectrometry). ESI can detect weak interactions such as cyclodextrin inclusion complexes, enzyme-substrate complexes, double stranded DNA and its intercalation with a ligand. It is expected to be a powerful tool for study of molecular recognition at the picomolar level. ESI can also be easily interfaced with liquid chromatography (LC/MS). On-line LC/MS is widely applicable for mixture analysis. MALDI-TOF provides extremely high sensitivity such as sub picomolar level analysis. PSD-MS (post source decay-mass spectrometry) gives structural information, which is a technique similar to CID-MS/MS with extremely high sensitivity.View full abstractDownload PDF (1176K) -
Atsushi NAKAGAWA1996 Volume 54 Issue 5 Pages 384-394
Published: May 01, 1996
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSThe synchrotron radiation (SR), which is produced in circular electron/positron accelerator, is high brilliance and pulsed white light with wide wavelength range, from infrared to γ-rays. Synchrotron radiation is the only light source which produce high intensity white light in hard X-ray region. Thus, it is used in various scientific field, such as physics, chemistry, biology, medical application, industrial application and so on. Many experiments, such as X-ray absorption fine structure (XAFS), X-ray fluorescence analysis and small angle X-ray scattering etc., are being worked with synchrotron radiation as light source. Biological macromolecular crystallography is one of the main application of synchrotron radiation. High intensity and high brilliance of synchrotron radiation is indispensable to collect good high resolution diffraction data from small crystals with large unit cell. Wavelength tunability can be applied to determine crystallographic phases using anomalous dispersion effect. White X-ray light opens a new field of crystallography, time-resolved dynamic structure determination using Laue technique. A next generation ultra-light source, SPring -8, is now under construction.View full abstractDownload PDF (2412K) -
Yoshio YAMAUCHI1996 Volume 54 Issue 5 Pages 395-399
Published: May 01, 1996
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSUtilization of supercritical fluids includes two methods;extraction (SFE) and chromatography (SFC). The most populer fluid may be carbon dioxide due to its easiness in control in the supercritical state. As a new concept of SFE using carbon dioxide, the programmed extraction elution method (PEEM) that enhances extraction efficiency and selectivity is presented, demonstrating the micro scale SFE preparation of naphthalene and anthracene.
Recently, SFC has been developed in various fields as HPLC. The author describes various applications;analysis of a surfactant uising negative temperature gradient elution method, chiral prep-separation of t-stilbene oxide, and separation and detection of SFC-MS.View full abstractDownload PDF (690K) -
Yuichi SUGANO1996 Volume 54 Issue 5 Pages 401-409
Published: May 01, 1996
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSTo allow non-invasive radiotracer studies in human, the emitted radiation must be detected outside the body. PET technique employs tracers labeled with short-lived positron emitting radionuclides that produce externally detectable two anti-parallel gamma photons by collision with an electron. By computerized reconstruction, cross section images of the distribution of the radioactivity can be created.
The short half-lives of the radionuclides minimize radiation-exposure and allow tht repetitive PET-investigations within short time intervals. The high specific radioactivity makes it possible to work with small concentration of the tracers.
PET has become increasingly important in biological and medical research. The development of new synthetic methods is eagerly desired to produce new tracers labeled with positron emitting radionuclides.View full abstractDownload PDF (1256K) -
Akihiko OUCHI1996 Volume 54 Issue 5 Pages 410-418
Published: May 01, 1996
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSUtilization of lasers in organic syntheses is reviewed. Firstly, characteristics of laser light are summarized. Secondly, photochemical processes of laser reactions are outlined with some examples of reactions. Thirdly, experimental apparatus and techniques in laser reactions are introduced.View full abstractDownload PDF (1225K) -
Yoshimasa FUKAZAWA, Takeharu HAINO1996 Volume 54 Issue 5 Pages 419-426
Published: May 01, 1996
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSComputer-assisted analysis for stereochemical outcome of organic reactions is now an important area in synthetic organic chemistry. Molecular mechanics method has been extensively utilized for the analysis. Ab initio type MO calculation is also used for the analysis, however, application of this method to large molecule systems is limited. The transition state modeling using a combination of the MM and MO methods is hence the practical choice for the theoretical investigation of organic reactions for large molecules. In this paper we reviewed the recent progress of the transition state modeling for some pericyclic, radical and polar organic reactions, as well as solvation treatment with MD and MC methods.View full abstractDownload PDF (1252K) -
Masaji ISHIGURO, Seiichi IMAJO1996 Volume 54 Issue 5 Pages 427-436
Published: May 01, 1996
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSComplex structures of neocarzinostatin (NCS) and β-lactamase/β-lactam antibiotics were built using NMR and crystallographic data of the proteins. On binding of ligands to proteins, particular amino acid side chains as well as ligands show dynamic character to exhibit specific molecular recognition. NMR studies and conformational analysis of the Phe 78 side chain of NCS revealed that the Phe 78 residue plays a major role on the chromophore binding through conformational change of the side chain aromatic moiety. Crystal structures and computational modeling of the enzyme-ligand complexes indicated that at the active site, the carboxylate of β-lactam antibiotics induces the conformational change of the Lys 73 residue and acts as a trigger of the hydrolytic reaction (acylation). Modeling of the acyl-enzyme structures also suggested the role of a mobile water molecule at the active site for deacylation. Experimental (NMR and X-ray crystallography) and computational results provided a fruitful information about molecular interaction between proteins and ligands.View full abstractDownload PDF (1437K) -
Hiroaki SASAI1996 Volume 54 Issue 5 Pages 437-444
Published: May 01, 1996
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSInternet makes it possible to send and receive data in high speed and in high quality. Now, sounds, graphics, and even movies can send over internet very easily. Herein, I would like to introduce some tips to use internet efficiently. With using internet, leaving scientists free to consider more important issues.View full abstractDownload PDF (2400K) -
[in Japanese], [in Japanese], [in Japanese], [in Japanese]1996 Volume 54 Issue 5 Pages 456
Published: May 01, 1996
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSDownload PDF (179K)
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