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Volume 49, Issue 4
Displaying 1-10 of 10 articles from this issue
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1991 Volume 49 Issue 4 Pages 278-287
Published: April 01, 1991
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSDownload PDF (1747K) -
Kunio MOCHIDA1991 Volume 49 Issue 4 Pages 288-294
Published: April 01, 1991
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSSyntheses, structures, and some reactions of organometallic compounds having germanium-metal bond have been reviewed forcusing on advances in 1980's.View full abstractDownload PDF (780K) -
Haruo OGURA1991 Volume 49 Issue 4 Pages 295-301
Published: April 01, 1991
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSNeu 5 Ac, the most important sialic acid was obtained from edible bird's nest, KDN was prepared from D-mannose and oxalacetic acid. KDN glycosides were synthesized by the Koenigs-Knorr reaction for cholesterol and Williamson method for phenols.
S, S′-Bis(1-phenyl-1H-tetrazol-5-yl) dithiocarbonate prepared from 5-mercapto-1-phenyl-1H-tetrazole and trichloromethyl chloroformate, was attempted to a novel glycosylation reagent. Sialosyllactose and sialosylcholesterol were synthesized by this method.
GM3 cholesterol analog and mitomycin derivatives were synthesized.View full abstractDownload PDF (626K) -
Yasufumi OHFUNE, Keiko SHIMAMOTO1991 Volume 49 Issue 4 Pages 302-313
Published: April 01, 1991
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSTo elucidate the conformational role of L-glutamic acid in activating its different types of excitatory receptors in the mammalian central nervous systems, we designed eight diastereomers of 2-(carboxycyclopropyl) glycine (L-CCG-IIV and D-CCG-IIV) which are the conformationally constrained analogues of glutamate as either the extended form or the folded form. The syntheses of CCGs were carried out using efficient methods (mainly based on palladium catalyzed inter- or intramolecular cyclopropanation) starting from chiral amino acids. Electrophysiological assay of all distereomers using the new born rat spinal cord demonstrated a large variety of depolarizing activities : D-CCG-II and L-CCG-IV were potent NMDA agonists and L-CCG- III markedly potentiated the response to L-glutamate. Moreover, L-CCG-I activated selectively the metabotropic receptor. The conformation-activity relationship of CCG isomers strongly suggested that NMDA receptor is activated by the folded form of glutamate and that the extended form of glutamate is crucial for the activation of metabotropic glutamate receptor.View full abstractDownload PDF (1657K) -
Structure, Function, and Application to Organic SynthesisYasuhisa ASANO1991 Volume 49 Issue 4 Pages 314-326
Published: April 01, 1991
Released on J-STAGE: January 28, 2010
JOURNAL FREE ACCESSA new enzyme named “D-Aminopeptidase” has been isolated and characterized from a soil bacterium Ochrobactrum anthropi, SCRC Cl-38. It showed strict D-stereospecificity toward substrates including low molecular weight D-amino acid amides, D-alanine N-alkylamides, and peptides with a D-alanine at the N-terminus. The gene for the enzyme was cloned in Escherichia coli and an expression plasmid constructed. The amount of the enzyme in the cell-free extract of an E. coli transformant was elevated up to 288, 000 units/liter culture, which is about 3, 600-fold over that of O. anthropi SCRC Cl-38. The deduced amino acid sequence of the enzyme showed that it is related to the “penicillin-recognizing enzymes”. Mutants of the enzyme were generated by site-specific mutagenesis. We propose that the enzyme is a new member of the “penicillin-recognizing enzymes”. The cells of E. coli transformant were used as a catalyst for the D-stereospecific hydrolysis of several racemic amino acid amides HCl. The concentration of D-alanine reached up to 220 g/liter from racemic alanine amide HCl. D-Amino acid N-alkylamides were stereoselectively synthesized in organic solvents from racemic amino acid esters by the use of the enzyme immobilized by urethane prepolymer PU-6. The enzyme was also active in synthesizing D-alanine oligopeptides in non-aqueous media.View full abstractDownload PDF (1674K) -
Kin-ichi TADANO, Jun ISHIHARA, Seiichiro OGAWA1991 Volume 49 Issue 4 Pages 327-339
Published: April 01, 1991
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSThe [3, 3] sigmatropic rearrangement, represented by Claisen rearrangement, is one of the promising synthetic tools for the carbon framework construction in natural product synthesis. The reliability of the stereochemical issue, especially being realizable in cyclic systems, is well recognized. In this article, we summarize our recent development in the field of the Claisen rearrangements applied to the carbohydrate-derived substrates. The highly stereoselective quaternization of the ring-carbon of the furanose derivatives is also featured in this context. The utility of the rearrangement strategy was substantiated through the first total synthesis of (-) -acetomycin, an antimicrobial and antitumor agent.View full abstractDownload PDF (1419K) -
Tsutomu KATSUKI1991 Volume 49 Issue 4 Pages 340-345
Published: April 01, 1991
Released on J-STAGE: November 16, 2009
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Kaichi TANIDA1991 Volume 49 Issue 4 Pages 346-347
Published: April 01, 1991
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSDownload PDF (181K) -
Kaichi TANIDA1991 Volume 49 Issue 4 Pages 348-349
Published: April 01, 1991
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSDownload PDF (163K) -
[in Japanese], [in Japanese], [in Japanese], [in Japanese]1991 Volume 49 Issue 4 Pages 350
Published: April 01, 1991
Released on J-STAGE: November 16, 2009
JOURNAL FREE ACCESSDownload PDF (164K)
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