512-69-6Relevant academic research and scientific papers
Transglycosylations employing recombinant α- And β-galactosidases and novel donor substrates
Schr?der, Sven,Kr?ger, Lars,Mattes, Ralf,Thiem, Joachim
, p. 157 - 166 (2015)
Recombinant α- and β-galactosidases could be prepared in larger amounts for chemoenzymatic syntheses of glycosylated oligosaccharides relevant in nutrition approaches. α-Galactosidase RafA from Escherichia coli, another thermophilic α-galactosidase AgaB from Geobacillus stearothermophilus KVE39, and also a thermophilic β-galactosidase BglT from Thermus thermophilus TH 125 could be employed in α- and in β-glycosylations, respectively. With model structures as well as sucrose, isomaltitol, and isomaltulose the stereo- and regiospecificities were studied. Further, a number of modified donor structures with structural variation and different leaving groups were synthesized, employed, and compared to classical donors for these transglycosylations.
Synthesis of raffinose family oligosaccharides by regioselective de-O-benzylation with Co2(CO)8/Et3SiH/CO system
Zhao, Yue-Tao,Niu, Shan,Huang, Lu-Bai,Wang, Ji-Ming,Yin, Zhao-Jun,Li, Qing,Li, Zhong-Jun
, p. 5022 - 5028 (2013/06/27)
A convenient approach for synthesis of raffinose, stachyose, and verbascose using sucrose as the starting material is presented. The key step is the regioselective de-O-benzylation with Co2(CO)8/Et 3SiH/CO system, followed by a high α-selective glycosylation. The newly developed de-O-benzylation system is efficient in removing the primary benzyl groups of sucrose and raffinose under mild condition and with high selectivity. Using thioglycoside as donor, NIS/AgOTf as promoter and DTBMP as additive, glycosylation of acid labile sucrose substrate is achieved in high yield.
Aspergillus nidulans α-galactosidase of glycoside hydrolase family 36 catalyses the formation of α-galacto-oligosaccharides by transglycosylation
Nakai, Hiroyuki,Baumann, Martin J.,Petersen, Bent O.,Westphal, Yvonne,Hachem, Maher Abou,Dilokpimol, Adiphol,Duus, Jens .,Schols, Henk A.,Svensson, Birte
experimental part, p. 3538 - 3551 (2011/11/05)
The α-galactosidase from Aspergillus nidulans (AglC) belongs to a phylogenetic cluster containing eukaryotic α-galactosidases and -galacto-oligosaccharide synthases of glycoside hydrolase family 36 (GH36). The recombinant AglC, produced in high yield (0.65 g·L-1 culture) as His-tag fusion in Escherichia coli, catalysed efficient transglycosylation with α-(1→6) regioselectivity from 40 mm 4-nitrophenol -d-galactopyranoside, melibiose or raffinose, resulting in a 37-74% yield of 4-nitrophenol α-d-Galp-(1→6) α-d-Galp, α-d-Galp- (1→6) α- d-Galp-(1→6) α-d-Glcp and α-d-Galp- (1→6) α- d-Galp-(1→6) α-d-Glcp-(1→2) α-d-Fruf (stachyose), respectively. Furthermore, among 10 monosaccharide acceptor candidates (400 mm) and the donor 4-nitrophenol -d-galactopyranoside (40 mm), -(1→6) linked galactodisaccharides were also obtained with galactose, glucose and mannose in high yields of 39-58%. AglC did not transglycosylate monosaccharides without the 6-hydroxymethyl group, i.e. xylose, l-arabinose, l-fucose and l-rhamnose, or with axial 3-OH, i.e. gulose, allose, altrose and l-rhamnose. Structural modelling using Thermotoga maritima GH36 -galactosidase as the template and superimposition of melibiose from the complex with human GH27 α-galactosidase supported that recognition at subsite +1 in AglC presumably requires a hydrogen bond between 3-OH and Trp358 and a hydrophobic environment around the C-6 hydroxymethyl group. In addition, successful transglycosylation of eight of 10 disaccharides (400 mm), except xylobiose and arabinobiose, indicated broad specificity for interaction with the +2 subsite. AglC thus transferred -galactosyl to 6-OH of the terminal residue in the -linked melibiose, maltose, trehalose, sucrose and turanose in 6-46% yield and the -linked lactose, lactulose and cellobiose in 28-38% yield. The product structures were identified using NMR and ESI-MS and five of the 13 identified products were novel, i.e. α-d-Galp-(1→6) α-d-Manp; α-d-Galp-(1→6) α- d-Glcp-(1→4) α-d-Glcp; α-d-Galp-(1→6) α- d-Galp-(1→4) α-d-Fruf; α-d-Galp-(1→6) α-d-Glcp-(1→1) α-d-Glcp; and α-d-Galp-(1→6) α- d-Glcp-(1→3) α-d-Fruf.
COMBINED USE OF DIPEPTIDYL PEPTIDASE IV INHIBITOR COMPOUND AND SWEETENER
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, (2010/01/29)
The present invention provides a novel therapeutic or preventive method, a pharmaceutical composition and use thereof, that exhibit superior anti-obesity effects (body weight-reducing (losing) effects and/or body fat mass-reducing effects). Specifically, the present invention provides a pharmaceutical composition comprising the combination of a dipeptidyl peptidase 4 inhibitor and a sweetener having a GLP-1 secretion-stimulating action, as well as use thereof for the manufacture of a medicament. The present invention also provides a method for treating or preventing obesity, comprising administering an effective amount of (a) a dipeptidyl peptidase 4 inhibitor and (b) a sweetener having a GLP-1 secretion-stimulating action to a patient suffering from symptoms of obesity.
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
Method for synthesizing oligosaccharides and glycosylation
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Page/Page column 7, (2009/04/24)
The invention relates to an enzymatic method for synthesizing oligosaccharides, whereby one saccharide group of a sucrose analogue each is transferred onto an acceptor molecule, for example for glycosylating a hydroxyl compound, a saccharide, peptide, or a drug. According to the inventive method, an enzymatic synthesis of β-D-fructofuranosyl-a-D-aldopyranoside is carried out in a first step, and in a second step one of the saccharide groups is enzymatically transferred onto the acceptor molecule.
First direct glycosylation of unprotected nonreducing mono- and disaccharides
Steinmann, Andreas,Thimm, Julian,Thiem, Joachim
, p. 5506 - 5513 (2008/09/17)
The first single-step random-glycosylation methodology for fully unprotected glycosyl acceptors is reported by random glycosylation leading to all possible regioisomers. For such systems conventional glycosylation methods such as Koenigs-Knorr glycosylation, Schmidt's trichloroacetimidate glycosylation and reactions employing glycosyl fluoride donors fail entirely. Starting from unprotected nonreducing saccharides, the glycosylation of β-glucosylated and β-galactosylated monosaccharides (Glc, Gal), symmetric disaccharides (e.g. α,α-trehaloses) as well as unsymmetric disaccharides (e.g. sucrose) were studied. The influence of base type and concentration were examined. Several libraries of di- and trisaccharides were generated. All regioisomers were formed in approximately equal proportions, and their partial separation was achieved by flash column chromatography. Even though it appears that overall yields are lower when comparing to classical protecting-group chemistry, this synthetic effort may be superior especially for access to higher saccharides. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
Synthesis of sucrose analogues and the mechanism of action of Bacillus subtilis fructosyltransferase (levansucrase)
Seibel, Juergen,Moraru, Roxana,Goetze, Sven,Buchholz, Klaus,Na'amnieh, Shukrallah,Pawlowski, Alice,Hecht, Hans-Juergen
, p. 2335 - 2349 (2007/10/03)
In the present study, we have coupled detailed acceptor and donor substrate studies of the fructosyltransferase (FTF, levansucrase) (EC 2.4.1.162) from Bacillus subtilis NCIMB 11871, with a structural model of the substrate enzyme complex in order to investigate in detail the roles of the active site amino acids in the catalytic action of the enzyme and the scope and limitation of substrates. Therefore we have isolated the ftf gene, expressed in Escherichia coli, yielding a levansucrase. Consequently, detailed acceptor property effects in the fructosylation by systematic variation of glycoside acceptors with respect to the positions (2, 3, 4 and 6) of the hydroxyl groups from equatorial to axial have been studied for preparative scale production of new oligosaccharides. Such investigations provided mechanistic insights of the FTF reaction. The configuration and the presence of the C-2 and C-3 hydroxyl groups of the glucopyranoside derivatives either as substrates or acceptors have been identified to be rate limiting for the trans-fructosylation process. The rates are rationalized on the basis of the coordination of d-glycopyranoside residues in 4C1 conformation with a network of amino acids by Arg360, Tyr411, Glu342, Trp85, Asp247 and Arg246 stabilization of both acceptors and substrates. In addition we also describe the first FTF reaction, which catalyzes the β-(1→2)-fructosyl transfer to 2-OH of l-sugars (l-glucose, l-rhamnose, l-galactose, l-fucose, l-xylose) presumably in a 1C4 conformation. In those conformations, the l-glycopyranosides are stabilized by the same hydrogen network. Structures of the acceptor products were determined by NMR and mass spectrometry analysis.
Thermodynamics of intermolecular interactions between saccharides and 18-crown-6 in water
Parfenyuk, Elena V.,Davydova, Olga I.,Lebedeva, Nataliya Sh.,Agafonov, Alexander V.
, p. 80 - 81 (2007/10/03)
The intermolecular complexes of D-galactose, D-maltose, sucrose and raffinose with 18-crown-6 were found to be entropy stabilised.
Composition and method for stimulating pollen germination
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, (2008/06/13)
Composition for application, in particular to leaves, comprising an excipient, the conventional constituents of compositions for application, in particular to leaves, and an active ingredient, characterized by the fact that the active ingredient is constituted by at least one phytosanitary product capable of stimulating the germination of pollen grains, selected from the group comprising: oligosaccharides having a degree of polymerization up to 10 and comprising up to 10, preferably up to 5 and, even more preferably, two glucidic units linked by β1-3, β1-4 et α1-3, particularly those of the group comprising laminaribiose, cellobiose, nigerose, laminaritriose, laminaritetraose and laminaripentaose, derivatives of the above oligosaccharides substituted on the free anomeric carbon atom or on all the carbon atoms having a free hydroxide by a radical selected from the group comprising: C1to C5alkyl radicals, preferably the methyl radical, C1to C5acyl radicals, preferably the acetyl radical, aryl radicals, preferably pyridylamino radicals, cycloalkyl radicals from Cxto Cy, amines, the N-acetyl radical and sulfate and phosphate radicals.
