10257-28-0Relevant articles and documents
QUERCETIN 3-O-GALACTOSYL-(1 -> 6)-GLUCOSIDE, A COMPOUND FROM NARROWLEAF WETCH WITH ANTIBACTERIAL ACTIVITY
Waage, Susan K.,Hedin, Paul A.
, p. 243 - 246 (1985)
A new flavonol glycoside, quercetin 3-O-galactosyl-(1 -> 6)-glucoside, has been isolated from above-ground parts of narrowleaf vetch, Vicia angustifolia.Its antibacterial activity against Pseudomonas maltophilia and Enterobacter cloacae is compared with that of several other flavonol glycosides.Key Word Index - Vicia angustifolia; Leguminosae; flavonol glycoside; quercetin; antibacterial.
75. New Triterpenoid N-Acetylglycosides with Molluscicidal Activity from Tetrapleura tetraptera TAUB
Maillard, Marc,Adewunmi, Clement O.,Hostettmann, Kurt
, p. 668 - 674 (1989)
Activity-guided fractionation of the MeOH extract of the fruits of Tetrapleura tetraptera TAUB. (Mimosaceae) afforded 4 saponins 1-4, which exhibited strong molluscicidal properties against the schistosomiasis-transmitting snails Biomphalaria glabrata.Chemical, enzymatic, and spectral methods (DCI-MS, 1H-NMR, 13C-NMR) showed that they were N-acetylglycosides of oleanolic acid and of echinocystic acid.Apart from saponin 1 (aridanin), previously isolated from this plant, glycosides 2-4 are new naturally occuring compounds.
Synthesis of some trifluoromethylated cyclodextrin derivatives and analysis of their properties as artificial glycosidases and oxidases
Bjerre, Jeannette,Fenger, Thomas Hauch,Marinescu, Lavinia G.,Bols, Mikael
, p. 704 - 710 (2007)
Cyclodextrin derivatives containing trifluoromethyl groups at C6 of the A and D rings were synthesized for the purpose of creating artificial enzymes. The compounds were synthesized by perbenzylation of β-cyclodextrin followed by selective A,D-debenzylation according to Sinay. Subsequent oxidation to dialdehyde with Dess-Martin periodinane followed by addition of CF3 by using Arduengo carbene and TMSCF3 led to the C6- bistrifluoromethylated alcohols. These were either deprotected by hydrogenolysis or subjected to another round of oxidation to provide the corresponding ketones that were deprotected. The trifluoromethylated alcohols were found to be weak artificial enzymes catalysing hydrolysis of nitrophenyl glycosides at neutral pH with a kcat/kuncat of up to 56. It is proposed that this catalysis is analogues to the catalysis performed by related cyanohydrins. The trifluoro ketones were likewise weak articial enzymes catalysing oxidation of amines to nitro derivatives or alcohols to ketones with a kcat/k uncat of up to 133. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
CHEMICAL STUDY OF PLANTS OF THE MONGOLIAN FLORA. COUMARINS OF Stellera chamaejasme: THE STRUCTURE OF CHAMAEJASMOSIDE - A NEW BICOUMARIN GLYCOSIDE
Narantuya, S.,Batsuren, D.,Rashkes, Ya. V.,Mil'grom, E. G.
, p. 197 - 199 (1994)
The coumarin composition of the epigeal part of Stellera chamaejasme has been studied.Together with the known coumarins daphnoretin, daphnetin, daphnin, and daphnorin, we have isolated the new bicoumarin glycoside chamaejasmoside and have established its structure by chemical transformations and a study of its spectral properties.Of the know coumarins, this is the first time that daphnorin and daphnin have been isolated from this plant.
Comparative study of new α-galactosidases in transglycosylation reactions
Spangenberg, Petra,Andre, Corinne,Dion, Michel,Rabiller, Claude,Mattes, Ralf
, p. 65 - 73 (2000)
We have studied the potential of several newly cloned α-galactosidases to catalyze the regioselective synthesis of disaccharides using 4-nitrophenylgalactoside as a donor. The kinetics of the reactions were followed by in situ NMR spectroscopy. The following thermophilic enzymes have been tested: Aga A and an isoenzyme Aga B obtained from the strain KVE39 and Aga 285 from the strain IT285 of Bacillus stearothermophilus; Aga T is an α-galactosidase from Thermus brockianus (strain IT360). Two other non-thermophilic α-galactosidases have also been evaluated: Aga 1 (Streptococcus mutans, strain Ingbritt) and Raf A (Escherichia coli, strain D1021). For all of the enzymes studied, high regioselectivity was observed leading to two (1 → 6)-disaccharides: 4-nitrophenyl α-D-galactopyranosyl-(1 → 6)-α-D-galactopyranoside and methyl α-D-galactopyranosyl-(1 → 6)-α-D-galactopyranoside, which were obtained in 54% (Aga B) and 20% (Aga T) yields, respectively. (C) 2000 Elsevier Science Ltd.
Distinct substrate specificities of three glycoside hydrolase family 42 β-galactosidases from Bifidobacterium longum subsp. infantis ATCC 15697
Viborg, Alexander H.,Katayama, Takane,Abou Hachem, Maher,Andersen, Mathias C.F.,Nishimoto, Mamoru,Clausen, Mads H.,Urashima, Tadasu,Svensson, Birte,Kitaoka, Motomitsu
, p. 208 - 216 (2014)
Glycoside hydrolase family 42 (GH42) includes β-galactosidases catalyzing the release of galactose (Gal) from the non-reducing end of different β-d-galactosides. Health-promoting probiotic bifidobacteria, which are important members of the human gastrointestinal tract microbiota, produce GH42 enzymes enabling utilization of β-galactosides exerting prebiotic effects. However, insight into the specificity of individual GH42 enzymes with respect to substrate monosaccharide composition, glycosidic linkage and degree of polymerization is lagging. Kinetic analysis of natural and synthetic substrates resembling various milk and plant galactooligosaccharides distinguishes the three GH42 members, Bga42A, Bga42B and Bga42C, encoded by the probiotic B. longum subsp. infantis ATCC 15697 and revealed the glycosyl residue at subsite +1 and its linkage to the terminal Gal at subsite -1 to be key specificity determinants. Bga42A thus prefers the β1-3-galactosidic linkage from human milk and other β1-3- and β1-6-galactosides with glucose or Gal situated at subsite +1. In contrast, Bga42B very efficiently hydrolyses 4-galactosyllactose (Galβ1-4Galβ1-4Glc) as well as 4-galactobiose (Galβ1-4Gal) and 4-galactotriose (Galβ1-4Galβ1-4Gal). The specificity of Bga42C resembles that of Bga42B, but the activity was one order of magnitude lower. Based on enzyme kinetics, gene organization and phylogenetic analyses, Bga42C is proposed to act in the metabolism of arabinogalactan- derived oligosaccharides. The distinct kinetic signatures of the three GH42 enzymes correlate to unique sequence motifs denoting specific clades in a GH42 phylogenetic tree providing novel insight into GH42 subspecificities. Overall, the data illustrate the metabolic adaptation of bifidobacteria to the β-galactoside-rich gut niche and emphasize the importance and diversity of β-galactoside metabolism in probiotic bifidobacteria. The Author 2013.
Two new triterpene saponins from Acanthophyllum laxiusculum
Pertuit, David,Baghery Lotfabad, Tayebe,Mitaine-Offer, Anne-Claire,Miyamoto, Tomofumi,Tanaka, Chiaki,Lacaille-Dubois, Marie-Aleth
, p. 611 - 617 (2015)
Two new triterpene glycosides, 1 and 2, together with three known ones, were isolated from roots of Acanthophyllum laxiusculum Schiman-Czeika. The structures of the new compounds were established by extensive 1D- and 2D-NMR spectroscopic experiments and MS analyses as 23-O-β-D-galactopyranosylgypsogenic acid 28-O-{β-D-glucopyranosyl-(1→2)-6-O-[4-carboxy-3-hydroxy-3-methyl-1-oxobutyl]-β-D-glucopyranosyl-(1→6)}-[β-D-glucopyranosyl-(1→3)]-β-D-galactopyranosyl ester (1) and gypsogenic acid 28-O-{β-D-glucopyranosyl-(1→2)-6-O-[4-carboxy-3-hydroxy-3-methyl-1-oxobutyl]-β-D-glucopyranosyl-(1→6)}-[β-D-glucopyranosyl-(1→3)]-β-D-galactopyranosyl ester (2).
KINETICS OF OXIDATION OF SOME DISACCHARIDES IN AMMONIACAL MEDIUM
Gupta, K. C.,Sharma, Anita,Misra, V. D.
, p. 2887 - 2893 (1981)
Kinetics of oxidation of lactose, maltose, cellobiose and melibiose has been studied by hexacyanoferrate(III) in the presence of ammonia.A general mechanism involving the formation of intermediate enodiol anion has been suggested.The effects of dielectric constant and salts have been studied in detail.The oxidation products have been characterised by descending paper chromatography.Compensation effects have been observed.
Remarkable supramolecular catalysis of glycoside hydrolysis by a cyclodextrin cyanohydrin
Ortega-Caballero, Fernando,Rousseau, Cyril,Christensen, Brian,Petersen, Torben Ellebaek,Bols, Mikael
, p. 3238 - 3239 (2005)
(6AR,6DR)-6A,6D-di-C-cyano-β-cyclodextrin (3) was synthesized and shown to catalyze hydrolysis of nitrophenyl glycosides with the reaction following Michaelis-Menten kinetics. At pH 7.4 and 25 °C, hydrolysis of 4-nitrophenyl-β-glucopyranoside (2) was catalyzed with KM = 15 mM, kcat = 8.2 × 10-6 s-1, and kcat/kuncat = 1217. Catalysis was observed with concentration of 3 as low as 10 μM. Hydrolysis of the corresponding α-glucoside, α-galactoside, α-mannoside, and 2-nitrophenyl-β-galactoside was also catalyzed by 3, with kcat/kuncat ranging from 283 to 2147. A series of analogues of 3 was prepared and investigated for catalysis of the hydrolysis of 2: (6AR,6DR)-6A,6D-di-C-propyl-β-cyclodextrin (9) was not catalytic, while 6A,6D-di-C-cyano-6A,6D-dideoxy-β-cyclodextrin (12) had a low catalytic activity (kcat/kuncat = 4). A kcatkuncat = 48 was found for 6A,6D-dialdehydo-β-cyclodextrin dihydrate (11). It was proposed that 3 acts by general acid catalysis on the bound substrate. Copyright
Steroidal saponins from the rhizomes of Smilacina henryi
Zhang, Xiao,Su, Yan-Fang,Chen, Lei,Huang, Xiong,Yan, Shi-Lun,Chai, Xin,Gao, Xiu-Mei
, p. 478 - 487 (2013)
Five steroidal saponins, namely henryiosides A-E (1-5), were isolated from the EtOH extract of the rhizomes of Smilacina henryi. Their structures were elucidated by the extensive use of 1D- and 2D-NMR experiments, along with HR-MALDI-MS analysis and the results of acid hydrolysis. The aglycones of henryiosides A-E possess a C(7)=C(8) or C(9)=C(11) bond and were not previously found in saponins. Copyright
