Asao Murai
Ajinomoto
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Publication
Featured researches published by Asao Murai.
Biochemical and Biophysical Research Communications | 1975
Masatsune Kainosho; Katsumi Ajisaka; Masako Kamisaku; Asao Murai; Yoshimasa Kyogoku
Abstract L-Phenylalanyl-(R)-[2H]glycine, L-valyl-(R)-[2H]glycine, and L-phenylalanyl [15N]glycine were prepared. Assignments for pro-R and pro-S proton NMR signals of the glycine residue were done and coupling constants between proton and 15N were obtained. Based on the data an attempt to explain the origin of the nonequivalence of the glycine methylene protons was made, and a conformational model for L-phenylalanylglycine is proposed.
Carbohydrate Research | 1973
Kazuo Matsuura; Younosuke Araki; Yoshiharu Ishido; Asao Murai; Katsuhiko Kushida
Abstract Irradiation of a solution of 3,4,6-tri- O -acetyl- D -glucal ( 1 ) in various mixtures of acetone ( 2 ) and isopropyl alcohol was investigated to elucidate solvent effects on the photochemical addition of 2 to 1 . At high concentrations of acetone ( 2 ), 5,6,8-tri- O -acetyl-2,4:3,7-dianhydro-1-deoxy-2- C -methyl- D - glycero - D - ido -octitol ( 3 ) was obtained selectively. In mixtures containing less than 50% (v/v) of 2 , irradiation gave mainly 5,6,8-tri- O -acetyl-3,7-anhydro-1,4-dideoxy-2- C -methyl- D - gluco -octitol ( 4 ). The effects of ethanol and other solvents were examined and the mechanism of the reaction is discussed.
Analytical Biochemistry | 1977
Hiroshi Iwase; Asao Murai
The fragmentation of eight volatile derivatives of alanine, valine, leucine, proline, and glutamic acid upon electron impact is studied for the concurrent ultramicrodetermination or the selective identification of amino acids by mass fragmentography. The relationship between the sensitivity of mass fragmentography and Σ10% values (percentage of the total ionization over me) of N-trifluoroacetyl-l-prolyl, N-benzoyl, and N-pentafluorobenzoyl derivatives of alanine, valine, leucine, and proline is also investigated. The results obtained in this study suggest that N-trifluoroacetyl-l-prolyl n-butyl ester, N-benzoyl n-butyl ester, N-pentafluorobenzoyl n-butyl ester, and N-trifluoroacetyl l-menthyl ester derivatives can be used for the concurrent ultramicrodetermination or selective identification of amino acids by mass fragmentography because these four derivatives produce common intense fragment ions at me 166, 105, 195, and 83 or diagnostic ions, respectively. Although N-trifluoroacetyl-l-4-thiazolidinecarbonyl n-butyl ester, N-trifluoroacetyl n-butyl ester, N-trimethylsilyl n-butyl ester, N-trimethylsilyl l-menthyl ester, and trimethylsilylated derivatives do not produce the common intense fragment ions, these derivatives are useful for the selective identification of ultra amounts of amino acids using mass fragmentography monitored the diagnostic ions, respectively. The general common rules between sensitivity and Σ10% values were not adhered among the derivatives studied.
Biochemical and Biophysical Research Communications | 1989
Satoko Akashi; Kazuo Hirayama; Asao Murai; Motoo Arai; Sawao Murao
This study indicates one of the advantages of tandem mass spectrometry; the primary structures of proteins with little structural difference can be determined by using tandem mass spectrometry without prior purification of each component. The primary structure of Paim II, a protein alpha-amylase inhibitor from Streptomyces coruchorushii, was determined by using tandem mass spectrometry. Paim II consists of two component proteins with ragged N-terminus, and was sequenced on the basis of the structure of Paim I, an analogous alpha-amylase inhibitor from the same natural origin.
Agricultural and biological chemistry | 1984
Hiroyuki Sato; Tadatoshi Seino; Takaaki Kobayashi; Asao Murai; Yasumi Yugari
Biochemistry | 1987
Kazuo Hirayama; Rei Takahashi; Satoko Akashi; Ken-ichi Fukuhara; Naoki Oouchi; Asao Murai; Motoo Arai; Sawao Murao; Kazuo Tanaka; Ittetsu Nojima
The Journal of Antibiotics | 1979
Yoko Takeuchi; Asao Murai; Yoshiyuki Takahara; Masatsune Kainosho
Journal of Mass Spectrometry | 1988
Satoko Akashi; Kazuo Hirayama; Tadatoshi Seino; Shinichi Ozawa; Ken-ichi Fukuhara; Naoki Oouchi; Asao Murai; Motoo Arai; Sawao Murao; Kazuo Tanaka; Ittetsu Nojima
Bulletin of the Chemical Society of Japan | 1986
Kazuo Hirayama; Toshihiko Ando; Rei Takahashi; Asao Murai
The Journal of Antibiotics | 1983
Shigeyoshi Miyashiro; Toshihiko Ando; Kazuo Hirayama; Takao Kida; Hiroshiro Shibai; Asao Murai; Tsuyoshi Shiio; Shigezo Udaka