Výsledky vyhledávání - "Yasuji Ihara"

Stereoselective hydrolysis of amino acid esters by modified polyethylenimines: Effects of quaternization of polymer and of added surfactants

Autor: Nobuhiko Kuroki, Mamoru Nango, Irving M. Klotz, Yoshiharu Kimura, Yasuji Ihara

Publikováno v: Journal of Polymer Science: Polymer Symposia. 71:167-182

Quaternized polyethylenimines exhibit viscosity behavior very similar to that of linear flexible polyelectrolytes and thus evidently swell in dilute salt solutions. This swelling is manifested also in the rate constants for the hydrolysis of chiral o

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::d0fcd39f9bbc2f9502a875367179cc6b
https://doi.org/10.1002/polc.5070710116

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Ab initio molecular orbital study on the mechanism of amide hydrolysis dependent on leaving groups

Autor: Kenzi Hori, Yasuji Ihara, Miyuki Mizumura, Akio Kamimura, Kaori Ando

Publikováno v: Tetrahedron. 53:4317-4330

The alkaline hydrolysis of amides, N-methyl acetamide 1, acetanilide 2, and N-acetyl imidazole 3, was investigated by use of ab initio molecular orbital calculations. A detailed analysis was performed for two possible mechanisms, Path 1 and 2. Path 1

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https://doi.org/10.1016/s0040-4020(97)00158-0

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A remarkably enhanced diastereoselectivity for the hydrolysis of dipeptide esters responding to pH and temperature in buffer solutions

Autor: Ryuichi Ueoka, Koichi Goto, Yoko Matsumoto, Akihiro Sakoguchi, Tetsuo Ito, Yoshito Matsumoto, Fumio Hirata, Shigeyuki Mori, Yasuji Ihara

Publikováno v: Tetrahedron Letters. 37:3461-3464

The remarkable high diastereoselectivity for the hydrolysis of Z-D(L)-Phe-L-Phe-PMCP ( DL LL = 40 ) or Z-D(L)-Phe-L-Phe-PNP ( DL LL = 130 ) was attained by regulating pH and temperature in buffer solutions.

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::57f2bdfab102f59e6e7afdf7ca83b77d
https://doi.org/10.1016/0040-4039(96)00590-4

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ChemInform Abstract: Kinetics and Molecular Modelling Studies on the Stereoselective Hydrolysis of Enantiomeric Esters by Dipeptide Catalysts

Autor: Kayo Igata, Satoko Asakawa, Yoko Matsumoto, Ryuichi Ueoka, Yasuji Ihara

Publikováno v: ChemInform. 22

The rate constants of the catalytic hydrolysis of short and long chain N-acylphenylalanine p-nitrophenyl esters by a series of optically active dipeptide catalysts in the presence of surfactant aggregates are presented in order to evaluate their cata

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https://doi.org/10.1002/chin.199128046

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Adsorption of anionic surfactants and related compounds from aqueous solution onto activated carbon and synthetic adsorbent

Autor: Yasuji Ihara

Publikováno v: Journal of Applied Polymer Science. 44:1837-1840

The adsorption isotherms of two anionic surfactants and sodium alkyl sulfonates with various carbon numbers onto activated carbon and synthetic adsorbent were measured in aqueous solutions. The adsorption affinities remarkably increased with an incre

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::2c95b078e8856ccbb28d49a4f531cab4
https://doi.org/10.1002/app.1992.070441017

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Cyclodextrin-Mediated Deacylation of Amino Acid Esters with Marked Stereoselectivity

Autor: Isao Toudo, Koichi Goto, Chikara Imamura, Satoshi Nukushina, Osamu Tanoue, Yasuji Ihara, Kentaro Nakashima, Ryuichi Ueoka, Yoko Matsumoto

Publikováno v: ChemInform. 34

With respect to the hydrolysis (deacylation) of Z-D(L)-amino acid esters (N-(benzyloxycarbonyl)-D(L)-amino acid p-nitrophenyl esters) mediated by alpha-, beta- and gamma-cyclodextrins (CyDs), a remarkably high enantioselectivity (L/D=9.0) was observe

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::2b5064166adbe552ed93ac112751c999
https://doi.org/10.1002/chin.200309181

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Diastereoselective Specificity for the Hydrolysis of Dipeptide Esters in Aqueous Media

Autor: Kouichi Goto, Yukito Murakami, Ryuichi Ueoka, Chikara Imamura, Shinya Yoshimitsu, Yasuji Ihara, Atsushi Miki, Osamu Tanoue

Publikováno v: Chemistry Letters. 28:73-74

The diastereoselectivity for the hydrolysis of p-methoxycarbonylphenyl N-(benzyloxycarbonyl)-D(L)-phenylalanyl-L-leucinate in aqueous solution was inverted by changing concentrations of the substrates or the reaction temperature. The monomer-aggregat

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::8686138a522b73ceea8b7b7c48e37a58
https://doi.org/10.1246/cl.1999.73

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