645-03-4Relevant articles and documents
Production of keto-disaccharides from aldo-disaccharides in subcritical aqueous ethanol
Gao, Da-Ming,Kobayashi, Takashi,Adachi, Shuji
, p. 998 - 1005 (2016/05/09)
Isomerization of disaccharides (maltose, isomaltose, cellobiose, lactose, melibiose, palatinose, sucrose, and trehalose) was investigated in subcritical aqueous ethanol. A marked increase in the isomerization of aldo-disaccharides to keto-disaccharides was noted and their hydrolytic reactions were suppressed with increasing ethanol concentration. Under any study condition, the maximum yield of keto-disaccharides produced from aldo-disaccharides linked by β-glycosidic bond was higher than that produced from aldo-disaccharides linked by α-glycosidic bond. Palatinose, a keto-disaccharide, mainly underwent decomposition rather than isomerization in subcritical water and subcritical aqueous ethanol. No isomerization was noted for the non-reducing disaccharides trehalose and sucrose. The rate constant of maltose to maltulose isomerization almost doubled by changing solvent from sub-critical water to 80 wt% aqueous ethanol at 220°C. Increased maltose monohydrate concentration in feed decreased the conversion of maltose and the maximum yield of maltulose, but increased the productivity of maltulose. The maximum productivity of maltulose was ca. 41 g/(h kg-solution).
Mode of action of a β-(1→6)-glucanase from Penicillium multicolor
Hattori, Takeshi,Kato, Yasuna,Uno, Shuji,Usui, Taichi
, p. 6 - 16 (2013/02/25)
β-(1→6)-Glucanase from the culture filtrate of Penicillium multicolor LAM7153 was purified by ammonium sulfate precipitation, followed by cation-exchange and affinity chromatography using gentiotetraose (Gen 4) as ligand. The hydrolytic mode of action of the purified protein on β-(1→6)-glucan (pustulan) was elucidated in real time during the reaction by HPAEC-PAD analysis. Gentiooligosaccharides (DP 2-9, Gen 2-9), methyl β-gentiooligosides (DP 2-6, Gen2-6 β-OMe), and p-nitrophenyl β-gentiooligosides (DP 2-6, Gen 2-6 β-pNP) were used as substrates to provide analytical insight into how the cleavage of pustulan (DP? 320) is actually achieved by the enzyme. The enzyme was shown to completely hydrolyze pustulan in three steps as follows. In the initial stage, the enzyme quickly cleaved the glucan with a pattern resembling an endo-hydrolase to produce a short-chain glucan (DP? 45) as an intermediate. In the midterm stage, the resulting short-chain glucan was further cleaved into two fractions corresponding to DP 15-7 and DP 2-4 with great regularity. In the final stage, the lower oligomers corresponding to DP 3 and DP 4 were very slowly hydrolyzed into glucose and gentiobiose (Gen 2). As a result, the hydrolytic cooperation of both an endo-type and saccharifying-type reaction by a single enzyme, which plays a bifunctional role, led to complete hydrolysis of the glucan. Thus, β-(1→6)-glucanase varies its mode of action depending on the chain length derived from the glucan.
Production of galacto-oligosaccharides by the β-galactosidase from kluyveromyces lactis: Comparative analysis of permeabilized cells versus soluble enzyme
Rodriguez-Colinas, Barbara,De Abreu, Miguel A.,Fernandez-Arrojo, Lucia,De Beer, Roseri,Poveda, Ana,Jimenez-Barbero, Jesus,Haltrich, Dietmar,Ballesteros Olmo, Antonio O.,Fernandez-Lobato, Maria,Plou, Francisco J.
experimental part, p. 10477 - 10484 (2012/07/17)
The transgalactosylation activity of Kluyveromyces lactis cells was studied in detail. Cells were permeabilized with ethanol and further lyophilized to facilitate the transit of substrates and products. The resulting biocatalyst was assayed for the synthesis of galacto-oligosaccharides (GOS) and compared with two soluble β-galactosidases from K. lactis (Lactozym 3000 L HP G and Maxilact LGX 5000). Using 400 g/L lactose, the maximum GOS yield, measured by HPAEC-PAD analysis, was 177 g/L (44% w/w of total carbohydrates). The major products synthesized were the disaccharides 6-galactobiose [Gal-β(1?6)-Gal] and allolactose [Gal-β(1?6)-Glc], as well as the trisaccharide 6-galactosyl-lactose [Gal-β(1?6)-Gal-β(1?4)-Glc], which was characterized by MS and 2D NMR. Structural characterization of another synthesized disaccharide, Gal-β(1?3)-Glc, was carried out. GOS yield obtained with soluble β-galactosidases was slightly lower (160 g/L for Lactozym 3000 L HP G and 154 g/L for Maxilact LGX 5000); however, the typical profile ith a maximum GOS concentration followed by partial hydrolysis of the newly formed oligosaccharides was not observed with the soluble enzymes. Results were correlated with the higher stability of β-galactosidase when permeabilized whole cells were used.
Identification of oligosaccharides formed during stachyose hydrolysis by pectinex ultra SP-L
Montilla, Antonia,Corzo, Nieves,Olano, Agustin,Jimen, Maria Luisa
experimental part, p. 5007 - 5013 (2010/06/14)
The commercial enzyme preparation Pectinex Ultra SP-L containing fructosyltransferase activity was used to hydrolyze stachyose. During this reaction, besides the formation of mono-, di-, and trisaccharides (DP 3), the presence of one pentasacch
Engineering of glucoside acceptors for the regioselective synthesis of β-(1→3)-disaccharides with glycosynthases
Marton, Zsuzanna,Tran, Vinh,Tellier, Charles,Dion, Michel,Drone, Jullien,Rabiller, Claude
experimental part, p. 2939 - 2946 (2009/04/06)
Glycosynthase mutants obtained from Thermotoga maritima were able to catalyze the regioselective synthesis of aryl β-d-Galp-(1→3)-β-d-Glcp and aryl β-d-Glcp-(1→3)-β-d-Glcp in high yields (up to 90 %) using aryl β-d-glucosides as acceptors. The need for an aglyconic aryl group was rationalized by molecular modeling calculations, which have emphasized a high stabilizing interaction of this group by stacking with W312 of the enzyme. Unfortunately, the deprotection of the aromatic group of the disaccharides was not possible without partial hydrolysis of the glycosidic bond. The replacement of aryl groups by benzyl ones could offer the opportunity to deprotect the anomeric position under very mild conditions. Assuming that benzyl acceptors could preserve the stabilizing stacking, benzyl β-d-glucoside firstly assayed as acceptor resulted in both poor yields and poor regioselectivity. Thus, we decided to undertake molecular modeling calculations in order to design which suitable substituted benzyl acceptors could be used. This study resulted in the choice of 2-biphenylmethyl β-d-glucopyranoside. This choice was validated experimentally, since the corresponding β-(1→3) disaccharide was obtained in good yields and with a high regioselectivity. At the same time, we have shown that phenyl 1-thio-β-d-glucopyranoside was also an excellent substrate leading to similar results as those obtained with the O-phenyl analogue. The NBS deprotection of the S-phenyl group afforded the corresponding disaccharide quantitatively.
Isolation and characterization of a β-primeverosidase-like enzyme from Penicillium multicolor
Tsuruhami, Kazutaka,Mori, Shigeharu,Amarume, Satoshi,Saruwatari, Shigetaka,Murata, Takeomi,Hirakake, Jun,Sakata, Kanzo,Usui, Taichi
, p. 691 - 698 (2008/02/08)
p-Nitrophenyl and eugenyl β-primeveroside (6-O-β-D-xylopyranosyl- β-D-glucopyranoside) hydrolytic activity was found in culture filtrate from Penicillium multicolor IAM7153, and the enzyme was isolated. The enzyme was purified as a β-primeverosidase-like enzyme by precipitation with ammonium sulfate followed by successive chromatographies on Phenyl Sepharose, Mono Q, and β-galactosylamidine affinity columns. The molecular mass was estimated to be 50 kDa by SDS-PAGE and gel filtration. The purified enzyme was highly specific toward the substrate p-nitrophenyl β-primeveroside, which was cleaved in an endo-manner into primeverose and p-nitrophenol, but a series of β-primeveroside as aroma precursors were hydrolyzed only slightly as substrates for the enzyme. In analyses of its hydrolytic action and kinetics, the enzyme showed narrow substrate specificity with respect to the aglycon and glycon moieties of the diglycoside. We conclude that the present enzyme is a kind of β-diglycosidase rather than β-primeverosidase.
Enzymatic syntheses and selective hydrolysis of O-β-d- galactopyranosides using a marine mollusc β-galactosidase
Giordano, Assunta,Tramice, Annabella,Andreotti, Giuseppina,Mollo, Ernesto,Trincone, Antonio
, p. 139 - 143 (2007/10/03)
The use of crude extract of the hepatopancreas of Aplysia fasciata, a large mollusc belonging to the order Anaspidea containing a β-galactosidase activity, was reported for the synthesis of different galactosides. Good yields with polar acceptors and the
A SINAPIC ACID ESTER FROM BOREAVA ORIENTALIS
Sakushima, Akiyo,Coskun, Maksut,Tanker, Mekin,Tanker, Nevin
, p. 1481 - 1484 (2007/10/02)
A new sinapic acid ester, 6-O-β-D-(2'-O-sinapoyl)glucopyranosyl β-D-(1,2-di-O-disinapoyl)glucopyranose, was identified from fruits of Boreava orientalis.Structural elucidation was carried out on the basis of UV, mass, 1H and 13C NMR spectral data, including 2D shift correlation and selective INEPT experiments.
Structure of the Klebsiella type 10 capsular polysaccharide.
Sarkar,Roy
, p. 205 - 215 (2007/10/02)
The capsular polysaccharide from Klebsiella Type 10 was found to contain D-galactose, D-glucose, D-mannose, and D-glucuronic acid in the ratios 3:1:1:1. Acid hydrolysis of the polysaccharide gave one aldobiouronic acid, one aldotriouronic acid, one aldotetraouronic acid, and two neutral disaccharides the structures of which were established. The native and carboxyl-reduced polysaccharide have been subjected as appropriate to methylation analysis and Smith degradation. Degradation of the methylated polysaccharide with base established the identity of the sugar unit preceding the glucosyluronic acid residue. The anomeric configurations of the sugar residues were determined by oxidation of the acetylated native and carboxyl-reduced polysaccharides with chromium trioxide. Based on these studies, the hexasaccharide structure 1 has been assigned to the repeating unit of the K-10 polysaccharide.
