- Glycon specificity profiling of α-glucosidases using monodeoxy and mono-O-methyl derivatives of p-nitrophenyl α-D-glucopyranoside
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Hydrolysis of probe substrates, eight possible monodeoxy and mono-O-methyl analogs of p-nitrophenyl α-D-glucopyranoside (pNP α-D-Glc), modified at the C-2, C-3, C-4, and C-6 positions, was studied as part of investigations into the glycon specificities of seven α-glucosidases (EC 3.2.1.20) isolated from Saccharomyces cerevisiae, Bacillus stearothermophilus, honeybee (two enzymes), sugar beet, flint corn, and Aspergillus niger. The glucosidases from sugar beet, flint corn, and A. niger were found to hydrolyze the 2-deoxy analogs with substantially higher activities than against pNP α-D-Glc. Moreover, the flint corn and A. niger enzymes showed hydrolyzing activities, although low, for the 3-deoxy analog. The other four α-glucosidases did not exhibit any activities for either the 2- or the 3-deoxy analogs. None of the seven enzymes exhibited any activities toward the 4-deoxy, 6-deoxy, or any of the methoxy analogs. The hydrolysis results, with the deoxy substrate analogs, demonstrated that α-glucosidases having remarkably different glycon specificities exist in nature. Further insight into the hydrolysis of deoxyglycosides was obtained by determining the kinetic parameters (kcat and Km) for the reactions of sugar beet, flint corn, and A. niger enzymes.
- Nishio, Toshiyuki,Hakamata, Wataru,Kimura, Atsuo,Chiba, Seiya,Takatsuki, Akira,Kawachi, Ryu,Oku, Tadatake
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- 3-deoxy oligosaccharides and pharmaceutical compositions containing them
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The invention relates to 3-deoxy oligosaccharides of formula I: STR1 in which X represents an --OSO3- radical, a radical of formula R--O, a radical of formula: STR2 or a radical of formula: STR3 Y represents a radical of formula: STR4 R represents an alkyl radical, R1, R3, R5, R7, R8, R10, R12 and R13 represent a hydroxyl radical, an alkoxy radical or an --OSO3- radical, R2, R4, R6, R9 and R11 represent a hydrogen atom, a hydroxyl radical, an alkoxy radical or an --OSO3- radical, with the proviso that at least R2 or R4 or R6 or R9 or R11 represents a hydrogen atom, and their pharmaceutically acceptable salts with a base.
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