- Transglycosylations employing recombinant α- And β-galactosidases and novel donor substrates
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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.
- Schr?der, Sven,Kr?ger, Lars,Mattes, Ralf,Thiem, Joachim
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- Synthesis of raffinose family oligosaccharides by regioselective de-O-benzylation with Co2(CO)8/Et3SiH/CO system
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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.
- Zhao, Yue-Tao,Niu, Shan,Huang, Lu-Bai,Wang, Ji-Ming,Yin, Zhao-Jun,Li, Qing,Li, Zhong-Jun
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p. 5022 - 5028
(2013/06/27)
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- Aspergillus nidulans α-galactosidase of glycoside hydrolase family 36 catalyses the formation of α-galacto-oligosaccharides by transglycosylation
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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.
- Nakai, Hiroyuki,Baumann, Martin J.,Petersen, Bent O.,Westphal, Yvonne,Hachem, Maher Abou,Dilokpimol, Adiphol,Duus, Jens .,Schols, Henk A.,Svensson, Birte
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experimental part
p. 3538 - 3551
(2011/11/05)
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- COMBINED USE OF DIPEPTIDYL PEPTIDASE IV INHIBITOR COMPOUND AND SWEETENER
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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.
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- Identification of oligosaccharides formed during stachyose hydrolysis by pectinex ultra SP-L
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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
- Montilla, Antonia,Corzo, Nieves,Olano, Agustin,Jimen, Maria Luisa
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experimental part
p. 5007 - 5013
(2010/06/14)
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- Method for synthesizing oligosaccharides and glycosylation
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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.
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Page/Page column 7
(2009/04/24)
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- First direct glycosylation of unprotected nonreducing mono- and disaccharides
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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.
- Steinmann, Andreas,Thimm, Julian,Thiem, Joachim
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p. 5506 - 5513
(2008/09/17)
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- Synthesis of sucrose analogues and the mechanism of action of Bacillus subtilis fructosyltransferase (levansucrase)
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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.
- Seibel, Juergen,Moraru, Roxana,Goetze, Sven,Buchholz, Klaus,Na'amnieh, Shukrallah,Pawlowski, Alice,Hecht, Hans-Juergen
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p. 2335 - 2349
(2007/10/03)
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- Thermodynamics of intermolecular interactions between saccharides and 18-crown-6 in water
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The intermolecular complexes of D-galactose, D-maltose, sucrose and raffinose with 18-crown-6 were found to be entropy stabilised.
- Parfenyuk, Elena V.,Davydova, Olga I.,Lebedeva, Nataliya Sh.,Agafonov, Alexander V.
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- Composition and method for stimulating pollen germination
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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.
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- Chrolactomycin compound
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The present invention relates to chrolactomycin compound represented by the following formula (I): STR1 or pharmaceutically acceptable salts thereof having antibacterial and antitumor activities.
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- Fermented milk product
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Lactic acid bacteria of the genus Lactobacillus having the following specific properties: (1) an increased amount of acidity of lactic acid when storing a product cultured by the bacteria at 10° C. for two weeks being 0.5% or less; (2) an activity of cell membrane bound adenosine triphosphatase-being 5 μmol.Pi/min/mg protein or less; and (3) the bacteria having neomycin resistance. Furthermore, a fermented milk product containing the lactic acid bacteria is disclosed.
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- Hexahydronaphthalene ester derivatives, their preparation and their therapeutic uses
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Compounds of formula (I): STR1 [wherein R1 represents a group of formula (II) or (III): STR2 R2 is alkyl, alkenyl or alkynyl; R3 and R4 are each hydrogen, alkyl, alkenyl or alkynyl; R5 is hydrogen or a carboxy-protecting group; Ra is hydrogen or a group of formula and --OR6 ; R6, R6a and R6b are each hydrogen, a hydroxy-protecting group, alkyl, alkanesulfonyl, halogenated alkanesulfonyl or arylsulfonyl] and their salts and esters have the ability to inhibit the synthesis of cholesterol, and can thus be used for the treatment and prophylaxis of hypercholesterolemia and of various cardiac disorders.
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- Pharmaceutical compositions comprising selected lactobacillus strains
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Topical pharmaceutical compositions, suited for the use in gynecology and urology, comprise as active principles selected Lactobacillus strains isolated from vaginal or urologic habitat of asymptomatic patients.
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- Pharmaceutical compositions comprising selected lactobacillus strains
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Topical pharmaceutical compositions, suited for the use in gynecolocy and urology, comprise as active principles selected Lactobacillus strains isolated from vaginal or urologic habitat of asymptomatic patients.
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- REGIOSELECTIVE SYNTHESIS OF TRISACCHARIDES BY USE OF A REVERSED HYDROLYSIS ACTIVITY OF α- AND β-D-GALACTOSIDASE
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Incubation of a solution containing D-galactose and a high concentration of sucrose in the presence of α-D-galactosidase from M. vinacea afforded raffinose and planteose in a ratio of ca. 3:2.On the other hand, circulation of a solution of D-galactose and sucrose through a reaction system consisting of columns, in series, of immobilized α-D-galactosidase and activated carbon gave only raffinose, eluted from the activated carbon column in a 17.6percent yield.Similarly, only isoraffinose was obtained in 10.6percent yield by the continuous method using an immobilized column of β-D-galactosidase from E. coli.
- Ajisaka, Katsumi,Fujimoto, Hiroshi
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p. 139 - 146
(2007/10/02)
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- Cologne consisting of microcapsule suspension
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Described are hydro-alcohol compositions of matter including, but not limited to, colognes, after-shave lotions, after-bath preparations and splash lotions, which yield continuously high fragrance intensity release, evenly and uniformly over an extended period of time and which can be adapted to yield differing aromas from a qualitative and quantitative standpoint in a controllable manner containing a mixture of (i) a non-confined fragrance composition; (ii) one or more fragrance oils which are physically entrapped in one or more types of solid particles and (iii) a suspending agent such as hydroxypropyl cellulose, silica, xanthan gum, ethyl cellulose or combinations of the previously mentioned four substances; the non-confined fragrance substance, the entrapped fragrance oil and the suspension agent being premixed prior to the subsequent creation of the hydro-alcohol compositions of matter.
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- Alpha-galactosidase production
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A process for the production of α-galactosidase by culturing the mold Penicillium duponti in an aqueous medium containing at least one sugar with at least one αD-galactopyranosyl bond and collecting the mycelium thus obtained.
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