2595-98-4Relevant articles and documents
Orthogonal Active-Site Labels for Mixed-Linkage endo-β-Glucanases
Jain, Namrata,Tamura, Kazune,Déjean, Guillaume,Van Petegem, Filip,Brumer, Harry
, p. 1968 - 1984 (2021/05/26)
Small molecule irreversible inhibitors are valuable tools for determining catalytically important active-site residues and revealing key details of the specificity, structure, and function of glycoside hydrolases (GHs). β-glucans that contain backbone β(1,3) linkages are widespread in nature, e.g., mixed-linkage β(1,3)/β(1,4)-glucans in the cell walls of higher plants and β(1,3)glucans in yeasts and algae. Commensurate with this ubiquity, a large diversity of mixed-linkage endoglucanases (MLGases, EC 3.2.1.73) and endo-β(1,3)-glucanases (laminarinases, EC 3.2.1.39 and EC 3.2.1.6) have evolved to specifically hydrolyze these polysaccharides, respectively, in environmental niches including the human gut. To facilitate biochemical and structural analysis of these GHs, with a focus on MLGases, we present here the facile chemo-enzymatic synthesis of a library of active-site-directed enzyme inhibitors based on mixed-linkage oligosaccharide scaffolds and N-bromoacetylglycosylamine or 2-fluoro-2-deoxyglycoside warheads. The effectiveness and irreversibility of these inhibitors were tested with exemplar MLGases and an endo-β(1,3)-glucanase. Notably, determination of inhibitor-bound crystal structures of a human-gut microbial MLGase from Glycoside Hydrolase Family 16 revealed.
Method for preparing lactic acid through catalytically converting carbohydrate
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Paragraph 0029-0040, (2020/11/01)
The invention relates to a method for preparing lactic acid through catalytically converting carbohydrate, and in particular, relates to a process for preparing lactic acid by catalytically convertingcarbohydrate under hydrothermal conditions. The method disclosed by the invention is characterized by specifically comprising the following steps: 1) adding carbohydrate and a catalyst into a closedhigh-pressure reaction kettle, and then adding pure water for mixing; 2) introducing nitrogen into the high-pressure reaction kettle to discharge air, introducing nitrogen of 2 MPa, stirring and heating to 160-300 DEG C, and carrying out reaction for 10-120 minutes; 3) putting the high-pressure reaction kettle in an ice-water bath, and cooling to room temperature; and 4) filtering the solution through a microporous filtering membrane to obtain the target product. The method can realize high conversion rate of carbohydrate and high yield of lactic acid, and has the advantages of less catalyst consumption, good circularity, small corrosion to reaction equipment and the like.
An Effective Heterogeneous Catalyst of [BMIM]3PMo12O40 for Selective Sugar Epimerization
Bayu, Asep,Yoshida, Akihiro,Karnjanakom, Surachai,Zuo, Zhijun,Hao, Xiaogang,Abudula, Abuliti,Guan, Guoqing
, p. 383 - 389 (2018/05/04)
The development of heterogeneous catalysts for the epimerization of sugars has received much less attention than that for the isomerization of sugars. To date, molybdates are the most effective catalysts for the epimerization of sugars, although they lack stability toward hydrolysis of their active sites in water. To solve the issue of the formation of a highly water-soluble heteropolyblue (PMored) for phosphomolybdates (PMos) in aqueous reaction systems, herein, a 1-butyl-3-methylimidazolium phosphomolybdate ([BMIM]3PMo12O40) was synthesized through an ion-exchange method. This catalyst was effective and selective for the C2-epimerization of sugars under mild reaction conditions (red was detected by means of UV/Vis spectroscopy. Moreover, the catalyst can be simply separated by filtration and reused for at least eight cycles without a drop in catalytic activity. XRD, FTIR, and X-ray photoelectron spectroscopy measurements indicate that the catalyst is stable under the reaction conditions. In a comparison of the catalytic activity and surface wettability with those of other PMo salts, that is, 1-ethyl-3-methylimidazolium phosphomolybdate ([EMIM]3PMo12O40), 1-hexyl-3-methylimidazolium ([HexMIM]3PMo12O40), [choline]3PMo12O40, and cetyltrimethylammonium phosphomolybdate ([CTA]3PMo12O40), it is found that [BMIM]3PMo12O40 has more appropriate hydrophobic–hydrophilic balance, which should be responsible for better catalytic activity and stability.
