- QUERCETIN 3-O-GALACTOSYL-(1 -> 6)-GLUCOSIDE, A COMPOUND FROM NARROWLEAF WETCH WITH ANTIBACTERIAL ACTIVITY
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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.
- Waage, Susan K.,Hedin, Paul A.
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- 75. New Triterpenoid N-Acetylglycosides with Molluscicidal Activity from Tetrapleura tetraptera TAUB
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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.
- Maillard, Marc,Adewunmi, Clement O.,Hostettmann, Kurt
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- Synthesis of some trifluoromethylated cyclodextrin derivatives and analysis of their properties as artificial glycosidases and oxidases
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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.
- Bjerre, Jeannette,Fenger, Thomas Hauch,Marinescu, Lavinia G.,Bols, Mikael
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- CHEMICAL STUDY OF PLANTS OF THE MONGOLIAN FLORA. COUMARINS OF Stellera chamaejasme: THE STRUCTURE OF CHAMAEJASMOSIDE - A NEW BICOUMARIN GLYCOSIDE
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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.
- Narantuya, S.,Batsuren, D.,Rashkes, Ya. V.,Mil'grom, E. G.
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- Comparative study of new α-galactosidases in transglycosylation reactions
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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.
- Spangenberg, Petra,Andre, Corinne,Dion, Michel,Rabiller, Claude,Mattes, Ralf
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- Distinct substrate specificities of three glycoside hydrolase family 42 β-galactosidases from Bifidobacterium longum subsp. infantis ATCC 15697
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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.
- Viborg, Alexander H.,Katayama, Takane,Abou Hachem, Maher,Andersen, Mathias C.F.,Nishimoto, Mamoru,Clausen, Mads H.,Urashima, Tadasu,Svensson, Birte,Kitaoka, Motomitsu
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- Two new triterpene saponins from Acanthophyllum laxiusculum
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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).
- Pertuit, David,Baghery Lotfabad, Tayebe,Mitaine-Offer, Anne-Claire,Miyamoto, Tomofumi,Tanaka, Chiaki,Lacaille-Dubois, Marie-Aleth
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- KINETICS OF OXIDATION OF SOME DISACCHARIDES IN AMMONIACAL MEDIUM
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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.
- Gupta, K. C.,Sharma, Anita,Misra, V. D.
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- Remarkable supramolecular catalysis of glycoside hydrolysis by a cyclodextrin cyanohydrin
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(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
- Ortega-Caballero, Fernando,Rousseau, Cyril,Christensen, Brian,Petersen, Torben Ellebaek,Bols, Mikael
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- Steroidal saponins from the rhizomes of Smilacina henryi
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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
- Zhang, Xiao,Su, Yan-Fang,Chen, Lei,Huang, Xiong,Yan, Shi-Lun,Chai, Xin,Gao, Xiu-Mei
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- Structures of steroidal alkaloid oligoglycosides, robeneosides A and B, and antidiabetogenic constituents from the Brazilian medicinal plant Solarium lycocarpum
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In the course of our studies on antidiabetogenic compounds from natural medicines and medicinal foodstuffs, a methanolic extract of the fruits of Solanum lycocarpum showed an inhibitory effect on the increase of serum glucose levels in oral sucrose-loaded rats. Through bioassay-guided separation, three known steroidal alkaloid oligoglycosides, solamargine (1), solasonine (3), and 12-hydroxysolasonine (5), were isolated from the active fraction together with two new steroidal alkaloid oligoglycosides, robeneosides A (2) and B (4). The major constituents, solamargine (1) and solasonine (3), exhibited an inhibitory effect on the increase of serum glucose levels in oral sucrose-loaded rats. In addition, these compounds suppressed gastric emptying in mice. However, this methanolic extract from S. lycocarpum fruits did not have any effect on intestinal a-glucosidase (sucrase and maltase) in vitro. It was concluded that these steroidal alkaloid oligoglycosides, 1 and 3, inhibited the increase of rat serum glucose levels by suppressing the transfer of sucrose from the stomach to the small intestine.
- Yoshikawa, Masayuki,Nakamura, Seikou,Ozaki, Kenichi,Kumahara, Akira,Morikawa, Toshio,Matsuda, Hisashi
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- PYRUVIC ACID-CONTAINING MONO- AND OLIGO-SACCHARIDES FROM Rhizobium trifolii BART A
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After partial, acid hydrolysis of the extracellular, acid polysaccharide from Rh. trifolii Bart A, the following products were isolated and characterised: 3,4-O-(1-carboxyethylidene)-D-galactose, 4,6-O-(1-carboxyethylidene)-D-galactose, 3-O-D-glucose, 3-O--D-glucose, O--(13)-O-β-D-glucopyranosyl-(14)-D-glucose, and O--(13)-O-β-D-glucopyranosyl-(14)-D-glucose.The presence of pyruvic acid linked either to O-3 and O-4 or to O-4 and O-6 of the D-galactopyranosyl group of these saccharides indicates that both structures may be present in the original polysaccharide.
- Somme, Randi
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- Illuminating the binding interactions of galactonoamidines during the inhibition of β-galactosidase (E. coli)
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Several galactonoamidines were previously identified as very potent competitive inhibitors that exhibit stabilizing hydrophobic interactions of the aglycon in the active site of β-galactosidase (Aspergillus oryzae). To elucidate the contributions of the glycon to the overall inhibition ability of the compounds, three glyconoamidine derivatives with alteration in the glycon at C-2 and C-4 were synthesized and evaluated herein. All amidines are competitive inhibitors of β-galactosidase (Escherichia coli) and show significantly reduced inhibition ability when compared to the parent. The results highlight strong hydrogen-bonding interactions between the hydroxyl group at C-2 of the amidine glycon and the active site of the enzyme. Slightly weaker H-bonds are promoted through the hydroxyl group at C-4. The inhibition constants were determined to be picomolar for the parent galactonoamidine, and nanomolar for the designed derivatives rendering all glyconoamidines very potent inhibitors of glycosidases albeit the derivatized amidines show up to 700-fold lower inhibition activity than the parent.
- Fan, Qiu-Hua,Pickens, Jessica B.,Striegler, Susanne,Gervaise, Cédric D.
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- Immobilization of β-Galactosidase from Aspergillus oryza on Magnetic Poly(GMA-ST) Beads
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In this study, novel magnetic beads were prepared from glycidylmethacrylate (GMA) and styrene (ST) via suspension polymerization with cyclohexanol and lauryl alcohol as porogenic agent. The magnetic poly (GMA-ST) beads were characterized with scanning electron microscope (SEM), magnetic scales and X-ray spectroscopy. The magnetic susceptibility of the porous poly (GMA-ST) beads was 1.25 × 10-4 cm3/g. Under the optimum conditions, β-galactosidase was immobilized on the magnetic poly (GMA-ST) beads described above, the results obtained showed that the activity of the immobilized β-galactosidase reached 412.09 U/g and the activity recovery was 61.32 %. Finally, the basic properties of the immobilized enzyme were determined separately and satisfactory results were obtained in pH stability, thermal stability, operational stability and Michaelis constants Km.
- Sun, Sufang,Zhao, Xiuying,Xu, Xiaobing
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- Oleanane glycosides from the roots of Alhagi maurorum
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Three new oleanane-type triterpene glycosides (1-3), along with four known compounds (4-7) glycosides, were isolated from the roots of Alhagi maurorum. Their structures were elucidated by 1D and 2D-NMR experiments as well as ESI-MS analysis. The antiproliferative activity of the isolated compounds was evaluated against a small panel of cancer cell lines including human breast cancer (MCF-7), human lung adenocarcinoma (A549), human prostate cancer (PC-3) and human leukemia (U937) cell lines. None of the tested compounds, in a range of concentrations between 1 and 50 μM, caused a significant reduction of the cell number.
- Hamed, Arafa,Perrone, Angela,Mahalel, Usama,Oleszek, Wieslaw,Stochmal, Anna,Piacente, Sonia
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- Two new glycosides from Duboscia macrocarpa Bocq.
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Two new compounds namely dubosciasides A (1) and B (2) were isolated from stem bark of Duboscia macrocarpa Bocq. together with three known flavonoids. Their structures were determined by spectroscopic methods including one- and two-dimensional NMR, EIMS and HRESIMS. The new compounds were identified as 6-C-β-d-apiofuranosyl-(1 → 4)-β-d-galactopyranosylnaringetol (1) and 1-O-α-l-rhamnopyranosyl-(1 → 4)-β-d-xylopyranosyl-3,4,5- trimethoxyphenol (2).
- Tchuendem, Marguerite H.K.,Douanla, Pascal D.,Tabopda, Turibio K.,Tchinda, Alembert T.,Tamze, Véronique,Nkengfack, Augustin E.,Abegaz, Berhanu M.,Connolly, Joseph D.
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- Two new acylated flavonol glycosides from the seeds of Lepidium sativum
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Two new acylated flavonol glycosides named kaempferol-3-O-(2-O-sinapoyl)- β-D-galactopyranosyl-(1→2)-β-D-glucopyranoside-7-O-α-L- rhamnopyranoside (1) and quercetin-3-O-(6-O-benzoyl)-β-D-glucopyranosyl- (1→3)-β-D-galactopyranoside-7-O-α-L-rhamnopyranoside
- Fan, Qing-Lu,Zhu, Yin-Di,Huang, Wen-Hua,Qi, Yun,Guo, Bao-Lin
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- High-throughput, quantitative enzyme kinetic analysis in microdroplets using stroboscopic epifluorescence imaging
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Droplet-based microfluidic systems offer a range of advantageous features for the investigation of enzyme kinetics, including high time resolution and the ability to probe extremely large numbers of discrete reactions while consuming low sample volumes. Kinetic measurements within droplet-based microfluidic systems are conventionally performed using single point detection schemes. Unfortunately, such an approach prohibits the measurement of an individual droplet over an extended period of time. Accordingly, we present a novel approach for the extensive characterization of enzyme-inhibitor reaction kinetics within a single experiment by tracking individual and rapidly moving droplets as they pass through an extended microfluidic channel. A series of heterogeneous and pL-volume droplets, containing varying concentrations of the fluorogenic substrate resorufin β-d-galactopyranoside and a constant amount of the enzyme β-galactosidase, is produced at frequencies in excess of 150 Hz. By stroboscopic manipulation of the excitation laser light and adoption of a dual view detection system, "blur-free" images containing up to 150 clearly distinguishable droplets per frame are extracted, which allow extraction of kinetic data from all formed droplets. The efficiency of this approach is demonstrated via a Michaelis-Menten analysis which yields a Michaelis constant, Km, of 353 μM. Additionally, the dissociation constant for the competitive inhibitor isopropyl β-d-1-thiogalactopyranoside is extracted using the same method.
- Hess, David,Rane, Anandkumar,Demello, Andrew J.,Stavrakis, Stavros
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- Flavonol glycosides with α-D-aldohexoses from Rhododendron irroratum
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Two new flavonol glycosides which contain rare α-D-galactose or α-D-glucose were obtained from the flowers of Rhododendron irroratum Franch., namely myricetin 3-O-β-D-galactoside-3′-O -α-D-glucoside (1) and myricetin 3-O-β-D-galactoside-3′-O- α-D-glucosid
- Yang, Ming Hua,Luo, Jian Guang,Huang, Xue Feng,Kong, Ling Yi
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- Antifungal saponins from bulbs of white onion, Allium cepa L.
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Three saponins, named ceposide A, ceposide B, and ceposide C were isolated from the bulbs of white onion, Allium cepa L. Elucidation of their structure was carried out by comprehensive spectroscopic analyses, including 2D NMR spectroscopy and mass spectrometry, and chemical evidences. The structures of the compounds were identified as (25R)-furost-5(6)-en-1β,3β,22α, 26-tetraol 1-O-β-d-xylopyranosyl 26-O-α-d-rhamnoyranosyl-(1 → 2)-O-β-d-galactopyranoside (ceposide A), (25R)-furost-5(6)-en-1β, 3β,22α,26-tetraol 1-O-β-d-xylopyranosyl 26-O-α-d- rhamnoyranosyl-(1 → 2)-O-β-d-glucopyranoside (ceposide B), and (25R)-furost-5(6)-en-1β,3β,22α,26-tetraol 1-O-β-d- galactopyranosyl 26-O-α-d-rhamnoyranosyl-(1 → 2)-O-β-d- galactopyranoside (ceposide C). The isolated compounds, alone and in combinations, were evaluated for their antimicrobial activity on ten fungal species. Antifungal activity of all three saponins increased with their concentration and varied with the following rank: ceposide B > ceposide A-ceposide C. We found a significant synergism in the antifungal activity of the three ceposides against Botrytis cinerea and Trichoderma atroviride, because growth of these fungi was strongly inhibited when the three saponins were applied in combination. In contrast, Fusarium oxysporum f. sp. lycopersici, Sclerotium cepivorum and Rhizoctonia solani were very little affected by saponins.
- Lanzotti, Virginia,Romano, Adriana,Lanzuise, Stefania,Bonanomi, Giuliano,Scala, Felice
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- Karataviosides G-K, five new bisdesmosidic steroidal glycosides from the bulbs of Allium karataviense
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We have analyzed the steroidal glycosides in Allium karataviense bulbs, and isolated five new bisdesmosidic steroidal glycosides: karataviosides G-K (1-5). The structures were elucidated by extensive spectroscopic analysis, including 2D NMR and enzymatic and hydrolytic cleavage. Karatavioside G (1) is an entirely novel furostanol glycoside, which has an O-β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranosyl unit at C-26 of the aglycone. Although a variety of cholestanol glycosides have been isolated, mainly from Liliaceae and Agavaceae, karataviosides J and K (4 and 5) are also notable because they are the most polar cholestanol bisdesmosides discovered, in which a lycotetraose is attached to C-3 of the aglycone, and a glucose or O-glucosyl-(1 → 3)-glucose is attached at C-16. The isolated glycosides were also evaluated for their cytotoxic activities against cultured tumor cell lines.
- Kuroda, Minpei,Ori, Kazutomo,Takayama, Hiroshi,Sakagami, Hiroshi,Mimaki, Yoshihiro
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- STEREOSELECTIVE RATE ENHANCEMENT OF MICELLE-CATALYZED HYDROLYSIS OF o-NITROPHENYL-β-D-GLUCOPYRANOSIDE
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The rate of hydrolysis of o-nitrophenyl-β-D-glucopyranoside was largely enhanced in the presence of cationic micelle and phenylboronic acid under alkaline conditions, while that of o-nitrophenyl-β-D-galactopyranoside was much less enhanced.
- Kodaka, Masato
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- β-GALACTOSIDASE FROM SUGAR CANE
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Key Word Index - Saccharum officinarium; Gramineae; sugar cane; β-galactosidase; cell wall. β-Galactosidase activity occurs in all of the organs of the sugar cane plant, and is also of general occurrence among different cultivars and species.Most of the activity was associated with the cell wall, and only ca 12-16 percent was an intercellular form.Both activities posess similar optimum pH and Km, both are activated by Mn2+ and ethanol, and inhibited by Hg2+, and both attack the same substrates.
- Etcheberrigaray, Juan Lorenzo,Vattuone, Marta Amelia,Sampietro, Antonio Rodolfo
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- Flavonol glycosides acylated with 3-hydroxy-3-methylglutaric acid as systematic characters in Rosa
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LC-UV-MS/MS analysis of leaf extracts from 146 accessions of 71 species of Rosa revealed that some taxa accumulated flavonol O-glycosides acylated with 3-hydroxy-3-methylglutaric acid, which are relatively uncommon in plants. The structures of two previou
- Porter, Elaine A.,Van Den Bos, Alexander A.,Kite, Geoffrey C.,Veitch, Nigel C.,Simmonds, Monique S.J.
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- Structural characterization of a new steroidal saponin from Agave angustifolia var. Marginata and a preliminary investigation of its in vivo antiulcerogenic activity and in vitro membrane permeability property
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A new furostane steroidal saponin was isolated from the leaves of Agave angustifolia var. marginata. On the basis of chemical conversions and spectroscopic analyses, its structure was established as 3-[O-β-D-glucopyranosyl-(1→3)-O-β-D-glucopyranosyl-(1→3)-O]-[O-6-deoxy-α-L-mannopyranosyl-(1→4)-β-D-xylopyranosyl-(1→2)-O-β-D-glucopyranosyl-(1→4)-β-D-galactopyranosyl)oxy]-(3β,5α,22α,25R)-26-(β-D-glucopyranosyloxy)-22-methoxy-furostane (1). Results of preliminary biological investigations indicated that compound 1 showed significant protective effects against induced gastric ulcers using in vivo experimental models and demonstrated negligible toxicity on membrane integrity in the in vitro assays.
- Pereira, Gabriela Moysés,Ribeiro, Marcela Gon?alves,da Silva, Bernadete Pereira,Parente, José Paz
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- Phenolic constituents of the inflorescences of Sorbus torminalis (L.) Crantz
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Torminaloside, a new acylated flavonol glycoside (3,5,7,4′- tetrahydroxy-3′-methoxyflavone-3-O-[6″-O-(3?-hydroxy- 3?-methylglutaroyl)]-β-d-galactopyranoside, 6), together with five further methoxylated flavones 1-5, hyperoside (7), isoquercitrin (8), chlorogenic acid (9) and neochlorogenic acid (10), were isolated for the first time from Sorbus torminalis (L.) Crantz. The structures of the isolates were elucidated by extensive spectroscopic studies, including UV, IR, 1D- and 2D-NMR, LSI-MS and HR-LSI-MS experiments. In addition to torminaloside, three further flavonoids: 5,7,4′-trihydroxy-3′-methoxyflavone-7-O-β-d- glucopyranoside (1), 3,5,7,4′-tetrahydroxy-8,3′-dimethoxyflavone-3- O-β-d-glucopyranoside (2), and 3,5,7,4′-tetrahydroxy-3′- methoxyflavone-3-O-β-d-galactopyranoside (4) were found for the first time in the genus Sorbus.
- Olszewska, Monika A.,Roj, Joanna Marta
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- Isolation, characterization and anti-inflammatory property of Thevetia Peruviana
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Thevetia peruviana seeds contain glucosides of neriifolin, acetylneriifolin and thevetin. Seed oil distillates of Thevetia peruviana have been found to contain anti-bacterial activity. In the persent work, the fresh flowers of Thevetia peruviana was subjected to phytochemical studies. The results of the study showed that the flowers contain quercetin, kaempferol and quercetin-7-o-galactoside. The structure of the isolated compound was characterized by UV, 1H NMR and 13C NMR spectra. The anti-inflammatory character of the isolated compound was tested by in vitro method and the results of the study revealed that the isolated compound showed a biphasic property.
- Thilagavathi,Kavitha, Helen P.,Venkatraman
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- Houttuynoids A-E, anti-herpes simplex virus active flavonoids with novel skeletons from Houttuynia cordata
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Houttuynoids A-E (1-5), a new type of flavonoid with houttuynin tethered to hyperoside, and their presumed biosynthetic precursor hyperoside (6) were isolated from the whole plant of Houttuynia cordata. Their structures were elucidated by analysis of 1D and 2D NMR. A hypothetical biogenetic pathway for houttuynoids A-E was proposed. Compounds 1-5 exhibited potent anti-HSV (herpes simplex viruses) activity.
- Chen, Shao-Dan,Gao, Hao,Zhu, Qin-Chang,Wang, Ya-Qi,Li, Ting,Mu, Zhen-Qiang,Wu, Hong-Ling,Peng, Tao,Yao, Xin-Sheng
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- Effect of magnesium cations on the activity and stability of β-galactosidases
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It was shown that the presence of magnesium cations in the reaction mixture increases, approximately twofold, the activity of bacterial Escherichia coli and yeast Kluyveromyces lactis β-galactosidases but does not affect the activity of bovine liver and f
- Atyaksheva,Pilipenko,Poltorak,Chukhrai
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- Desmettianosides A and B, bisdesmosidic furostanol saponins with molluscicidal activity from Yucca desmettiana
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Bioactivity-guided separation of the aqueous methanolic extract of Yucca desmettiana leaves, which in a preliminary screening exhibited significant molluscicidal activity, led to the isolation and structure elucidation of two new steroidal saponins (1 and 2). The structures of desmettianosides A and B, identified as bisdesmosidic furostanol glycosides with six and five sugar units, respectively, were established by detailed spectroscopic analyses of their NMR and MS data. Compounds 1 and 2 exhibited high molluscicidal activity against Biomphalaria alexandrina snails with LC100 values of 6 and 11 mg/L, respectively.
- Diab, Yasser,Ioannou, Efstathia,Emam, Ahmed,Vagias, Constantinos,Roussis, Vassilios
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- Synthesis and biological evaluation of a novel MUC1 glycopeptide conjugate vaccine candidate comprising a 4'-deoxy-4'-fluoro-Thomsen-Friedenreich epitope
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The development of selective anticancer vaccines that provide enhanced protection against tumor recurrence and metastasis has been the subject of intense research in the scientific community. The tumor-associated glycoprotein MUC1 represents a well-established target for cancer immunotherapy and has been used for the construction of various synthetic vaccine candidates. However, many of these vaccine prototypes suffer from an inherent low immunogenicity and are susceptible to rapid in vivo degradation. To overcome these drawbacks, novel fluorinated MUC1 glycopeptide-BSA/TTox conjugate vaccines have been prepared. Immunization of mice with the 4'F-TF-MUC1-TTox conjugate resulted in strong immune responses overriding the natural tolerance against MUC1 and producing selective IgG antibodies that are cross-reactive with native MUC1 epitopes on MCF-7 human cancer cells.
- Johannes, Manuel,Reindl, Maximilian,Gerlitzki, Bastian,Schmitt, Edgar,Hoffmann-R?der, Anja
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- β-Galactosidase transferase activity in ice and use of vinyl-β-D-galactoside as donor
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The ability of vinyl-β-D-galactoside as a donor in transglycosylation reactions catalysed by the β-glycosidase from Aspergillus oryzae using allylic alcohol and methyl-α-galactoside as acceptors is tested. A kinetic study made in comparison with another donor, the 2-nitrophenyl-β-D-galactoside, shows that the use of the latter leads at room temperature to better yields than those obtained from the former. A reverse situation is observed in ice at -7°C, conditions in which the yield for transglycosylation can be enhanced from 59% to 82% with methyl-α-galactoside as an acceptor.
- Chiffoleau-Giraud,Spangenberg,Rabiller
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- New triterpene saponins from the roots of Acacia macrostachya (Mimosaceae)
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Four new oleanane-type saponins, macrostachyaosides A, B, C, and D (1–4) were isolated from the roots of Acacia macrostachya. Their structures were elucidated on the basis of extensive 1D- and 2D-NMR data and HR-ESI-MS analyses. At concentrations of 100 μM of each compounds, none of the tested compounds caused a significant growth reduction against HL60 cells.
- Tchoukoua, Abdou,Tabopda, Turibio Kuiate,Usukhbayar, Narandulam,Kimura, Ken-ichi,Kwon, Eunsang,Momma, Hiroyuki,Koseki, Takuya,Shiono, Yoshihito,Ngadjui, Bonaventure Tchaleu
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- The phenolic acids from Oplopanax elatus Nakai stems and their potential photo-damage prevention activity
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25 phenolic acids, including four new isolates, eurylophenosides A–D (1–4) and 21 known ones (5–25) were isolated and identified from the stems of Oplopanax elatus Nakai. Among the known compounds 5–9, 11–13, 16, 18–25 were isolated from the genus for the first time; 17 was first obtained from the plant; and the NMR data of 22 was reported here first. Meanwhile, the UVB-induced photodamage model of HaCaT cells was used to study the prevent-photodamage abilities of compounds 1–2, 4–8, 11–13 and 15–25 with a nontoxic concentration at 50?μM. Moreover, a dose-dependent experiment was conducted for active compounds at the concentration of 10, 25, and 50?μM, respectively. Consequently, pretreatment with compounds 1, 16, 17, 19, 20, 22, 24 and 25 could suppress the cell viability decreasing induced by UVB irradiation in a concentration-dependent manner. These results indicated that phenolic acids were one kind of material basis with prevent-photodamage activity of O. elatus. Graphic abstract: [Figure not available: see fulltext.].
- Han, Yu,Cheng, Dongsheng,Hao, Mimi,Yan, Jiejing,Ruan, Jingya,Han, Lifeng,Zhang, Yi,Wang, Tao
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- Kaempferol and its glycosides from Equisetum silvaticum L. from the khanty-mansi autonomous area
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Three flavonoids were isolated from the aerial part of the wood horsetail (Equisetum silvaticum L.); two of them were found for the first time. The compounds were identified as kaempferol, kaempferol 3-O-β-D-galactopyranosyl-7-O-α-L-rhamnopyranoside and kaempferol 3-O-rutinosyl-7-O-L-rhamnopyranoside on the basis of the chemical transformations and IR, UV, 1H-NMR and mass spectra.
- Bonacheva,Botirov, E. Kh.
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- TWO ISOFLAVONE GALACTOSIDES FROM DALBERGIA SPINOSA
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Key Word Index-Dalbergia spinosa; Leguminosae; leaves; prunetin 4'-O-β-D-galactoside; 7-methyltectorigenin 4'-O-β-D-galactoside; stem-bark; known isoflavones.Abstract-The chemical examination of the leaves and steam-bark of Dalbergia spinosa has yielded, in addition to a number of known isoflavones, two new isoflavone galactosides, prunetin 4'-O-β-D-galactoside and 7-methyltectorigenin 4'-O-β-D-galactoside.
- Narayanan, Venkateswaran,Nagarajan, Natesan Shanmugan
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- Antifungal saponins from bulbs of garlic, Allium sativum L. var. Voghiera
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A bioassay-guided phytochemical analysis of the polar extract from the bulbs of garlic, Allium sativum L., var. Voghiera, typical of Voghiera, Ferrara (Italy), allowed the isolation of ten furostanol saponins; voghieroside A1/A2 and voghieroside B1/B2, based on the rare agapanthagenin aglycone; voghieroside C1/C2, based on agigenin aglycone; and voghieroside D1/D2 and E1/E2, based on gitogenin aglycone. In addition, we found two known spirostanol saponins, agigenin 3-O-trisaccharide and gitogenin 3-O-tetrasaccharide. The chemical structures of the isolated compounds were established through a combination of extensive nuclear magnetic resonance, mass spectrometry and chemical analyses. High concentrations of two eugenol diglycosides were also found for the first time in Allium spp. The isolated compounds were evaluated for their antimicrobial activity towards two fungal species, the air-borne pathogen Botrytis cinerea and the antagonistic fungus Trichoderma harzianum.
- Lanzotti, Virginia,Barile, Elisa,Antignani, Vincenzo,Bonanomi, Giuliano,Scala, Felice
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- Bacillus circulans β-galactosidase catalyses the synthesis of N-acetyl-lactosamine in a hydro-organic medium via a steady-state ordered Bi Bi reaction mechanism
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Starting from a galactosyl donor, the β-galactosidase from Bacillus circulans (Lactoles L3; BcβGal) catalyses the transgalactosylation of N-acetyl-d-glucosamine (GlcNAc) in hydro-organic media, leading to the synthesis of N-acetyl-lactosamine (LacNAc). The aim of this study was to determine the kinetic properties of LacNAc synthesis and sought to highlight the effect of the organic solvent on the enzyme kinetic parameters. Analyses of enzyme kinetics were performed in aqueous solutions and water/tert-butanol mixtures. A steady-state ordered Bi Bi mechanism was characterised for the transgalactosylation of GlcNAc catalysed by BcβGal in water/tert-butanol (70:30, v/v) mixtures, starting from o-nitrophenyl-β-d- galactopyranoside (oNPG) as a galactosyl donor. Moreover, tert-butanol was shown to have various effects on the kinetic parameters of the total transformation of oNPG and lactose catalysed by BcβGal, which led us to liken this solvent to a noncompetitive inhibitor towards the former and a competitive inhibitor towards the latter.
- Bridiau, Nicolas,Maugard, Thierry
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- Flavonoid characterization and in vitro antioxidant activity of Aconitum anthora L. (Ranunculaceae)
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In this paper, we report studies on morphological, phytochemical, and biological aspects of a population belonging to Aconitum anthora L. Two compounds, quercetin 3-O-((β-d-glucopyranosyl-(1→3)-(4-O-(E-p-coumaroyl))-α-l -rhamnopyranosyl-(1→6)-β-d-galactopyranoside))-7-O-α-l-r hamnopyranoside (1) and kaempferol 3-O-((β-d-glucopyranosyl-(1→3)-(4-O-(E-p-coumaroyl))-α-l -rhamnopyranosyl-(1→6)-β-d-galactopyranoside))-7-O-α-l-r hamnopyranoside (2), together with two known flavonol glycosides (3-4) were isolated and identified from A. anthora. The antioxidant activity of the four identified flavonoids was screened by three in vitro tests.
- Mariani, Cristina,Braca, Alessandra,Vitalini, Sara,De Tommasi, Nunziatina,Visioli, Francesco,Fico, Gelsomina
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- A new flavonol glycoside from the seeds of Nigella glandulifera
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A new flavonol glycoside, kaempferol 3-O-α-L-rhamnopyranosyl (1→6)-O-[β-D-glucopyranosyl (1→2)-O-β-D-galactopyranosyl (1→2)]-O- β-D-glucopyranoside (1), together with a known compound, kaempferol 3-O-β-D-glucopyranosyl (1→2)-O-β-D-galactopyranosyl (1→2)-O-β-Dglucopyranoside (2) was isolated from the seeds of Nigella glandulifera. Their structures were elucidated on the basis of spectral analysis, including ESI-MS, ESI-MS/MS, HR-ESI-MS, DQF-COSY, TOCSY, HSQC and HMBC techniques.
- Liu, Yu-Ming,Liu, Qing-Hua,Chen, Bao-Quan
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- Structure elucidation of secondary metabolites isolated from the leaves of Ixora undulate and their inhibitory activity toward advanced glycation end-products formation
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Three aromatic glycosides (1-3), two sulfur and nitrogen-containing compound glucosides (4, 5), and one flavonoid glycoside (6) were isolated from the leaves of Ixora undulata. Their structures were established by extensive 1D, 2D NMR, and HRESIMS experim
- Sugimoto, Sachiko,Wanas, Amira Samir,Mizuta, Tsutomu,Matsunami, Katsuyoshi,Kamel, Mohamed Salah,Otsuka, Hideaki
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- New Steroidal Saponins from the Leaves of Yucca elephantipes
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Two new spirostanol saponins, namely elephanosides G and H (1 and 2, resp.) were isolated from the leaves of Yucca elephantipes (Agavaceae), together with the two known furostanol saponins 3 and 4 and the six known flavonoid O- and C-glycosides 5-10. The
- Zhang, Ying,Yang, Chong-Ren,Zhang, Ying-Jun
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- Flavonol glycosides and steroidal saponins from the leaves of Cestrum nocturnum and their cytotoxicity
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Phytochemical analysis of the leaves of Cestrum nocturnum (Solanaceae) resulted in the isolation of two new flavonol glycosides (1, 2) and seven steroidal saponins (3-9), including four new ones (4, 6, 7, and 9). The structures of the new compounds were d
- Mimaki, Yoshihiro,Watanabe, Kazuki,Ando, Yuka,Sakuma, Chiseko,Sashida, Yutaka,Furuya, Shigenori,Sakagami, Hiroshi
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- Two new flavonol glycosides from Polygala sibirica L. Var megalopha Fr.
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Two new flavonol glycosides, named polygalin H (1) and polygalin I (2), as well as the known compound polygalin D (3), were isolated from the whole plant of Polygala sibirica L. var megalopha Fr. Their structures were elucidated on the basis of spectroscopic data analysis. These flavonol glycosides exhibited strong inhibitory activities against xanthine oxidase in vitro. Their half-maximal inhibitory concentrations (IC50) were calculated, which were 9.48, 8.31, 16.00 μM, respectively.
- Huang, Yan-Jie,Zhou, Ling-Yun,Wang, Jun-Min,Li, Qiang,Geng, Yuan-Yuan,Liu, Hai-Yang,Hua, Yan,McPhee, Derek J.
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- Antiproliferative steroidal glycosides from Digitalis ciliata
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Two new compounds, a furostanol glycoside (1) and a pregnane glycoside (4), along with eight known compounds, belonging to the classes of spirostane (2,3), pregnane (5-7) and cardenolide (8-10) glycosides, were isolated from the seeds of Digitalis ciliata. Their structures were elucidated by 1D and 2D-NMR experiments as well as ESI-MS analysis. For the first time pregnane glycosides of the diginigenin series have been isolated from D. ciliata. The cytotoxic effects of compounds 1-10 on cell viability of several cancer cell lines, namely human breast cancer (MCF-7), human glioblastoma (T98G), human lung adenocarcinoma (A549), human colon carcinoma (HT-29), and human prostate cancer (PC-3) cell lines were evaluated. Compounds 1, 4, 7 and 8 showed antiproliferative effects against MCF-7, HT-29 and A549 cancer cells with IC50 values ranging from 8.3 to 20 μM. The effects of compounds 1-10 on cell proliferation were evaluated on these three cancer cell lines by cell cycle analysis of DNA content using flow cytometry. Compounds 7, 8 and 10 induced significant changes in G2/M cell cycle phase of all analyzed cells. The obtained results indicate that compounds 7, 8 and 10 are cytostatic compounds effective in reducing cell proliferation by inducing accumulation of the cells in the G2/M phase of the cell cycle.
- Perrone, Angela,Capasso, Anna,Festa, Michela,Kemertelidze, Ether,Pizza, Cosimo,Skhirtladze, Alexandre,Piacente, Sonia
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- Probing the Neuraminidase Activity of Influenza Virus Using a Cytolysin A Protein Nanopore
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Neuraminidase (NA), one of the major surface glycoproteins of influenza A virus (IAV), is an important diagnostic biomarker and antiviral therapeutic target. Cytolysin A (ClyA) is a nanopore sensor with an internal constriction of 3.3 nm, enabling the detection of protein conformations at the single-molecule level. In this study, a nanopore-based approach is developed for analysis of the enzymatic activity of NA, which facilitates rapid and highly sensitive diagnosis of IAV. Current blockade analysis of the d-glucose/d-galactose-binding protein (GBP) trapped within a type I ClyA-AS (ClyA mutant) nanopore reveals that galactose cleaved from sialyl-galactose by NA of the influenza virus can be detected in real time and at the single-molecule level. Our results show that this nanopore sensor can quantitatively measure the activity of NA with 40-80-fold higher sensitivity than those previously reported. Furthermore, the inhibition of NA is monitored using small-molecule antiviral drugs, such as zanamivir. Taken together, our results reveal that the ClyA protein nanopore can be a valuable platform for the rapid and sensitive point-of-care diagnosis of influenza and for drug screening against the NA target.
- Kwak, Dong-Kyu,Kim, Jin-Sik,Lee, Mi-Kyung,Ryu, Kyoung-Seok,Chi, Seung-Wook
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- Polythosides A and B, two new triterpenoid saponins from the roots of Acacia polyacantha Willd. (Mimosaceae)
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Two new oleanane-type triterpene saponins, named polythosides A and B (1 and 2), together with a known compound, silphioside E (3), were isolated from the roots of Acacia polyacantha. Their structures were elucidated by analysis of 1D and 2D-NMR experiments, and mass spectrometry (HR-ESITOF-MS) as oleanolic acid 3-O-β-D-galactopyranosyl-(1→2)-β-D-xylopyranosyl-(1→6)-[β-D-xylopyranosyl-(1→4)]-[β-D-xylopyranosyl-(1→2)]-β-D-galactopyranoside (1), 3-O-[β-D-galactopyranosyl-(1→2)-β-D-xylopyranosyl-(1→6)-[β-D-xylopyranosyl-(1→4)]-[β-D-xylopyranosyl-(1→2)]-β-D-galactopyranosyl] oleanolic acid-28-O-β-D-glucopyranosyl ester (2) and 3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl] oleanolic acid 28-O-β-D-glucopyranosyl ester (3). The cytotoxic effect of isolated saponins was evaluated on the H4IIE rat hepatoma cell line. The results show that none of the compounds (assayed at 100 μM) showed cytotoxicity against H4IIE cells.
- Tchoukoua, Abdou,Tomfeun Nganou, Sandrine Carole,Dabole, Bernard,Yoshida, Jun,Ito, Yoshiaki,Ngadjui, Bonaventure Tchaleu,Shiono, Yoshihito
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p. 190 - 195
(2021/05/03)
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- Identification of potential anti-inflammatory and melanoma cytotoxic compounds from Aegiceras corniculatum
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Many chemicals found in mangroves reportedly exhibit potent anticancer, antibacterial, anti-inflammatory, antioxidant, and antitumor properties. Several of such compounds include feature unique structures and display interesting pharmacological effects. Few medicinal mangrove plants from Vietnam have been characterized with regard to their chemical constituents. Aegiceras corniculatum (L.) Blanco is a mangrove shrub that exhibits activity against various types of cancer. To identify new secondary metabolites and determine the source(s) of biological activity in Vietnamese medicinal mangrove plants, the chemical constituents of A. corniculatum were isolated, and their structures were appropriately established using common spectroscopic methods (1D and 2D-NMR, IR, HR-ESI-MS), and by producing derivatives by chemical reactions. Complementarily, it is worth noting, that the anti-inflammatory effects of the isolated compounds were investigated by measuring the production of pro-inflammatory cytokines IL-12 p40, IL-6, and TNF-α in lipopolysaccharide-stimulated bone marrow-derived dendritic cells; in this sense, the target compounds 2 and 3 were potent inhibitors of cytokines TNF-α, IL-6, and IL-12 p40, indicating promising anti-inflammatory effects. Furthermore, compounds 1 and 4 strongly promoted apoptosis of B16F10 melanoma cells. It is convenient to highlight, that the obtained results suggest that saponins from A. corniculatum could be potential candidates for treating cancer and inflammatory illnesses.
- Vinh, Le Ba,Phong, Nguyen Viet,Ali, Irshad,Dan, Gao,Koh, Young Sang,Anh, Hoang Le Tuan,Van Anh, Do Thi,Yang, Seo Young,Kim, Young Ho
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p. 2020 - 2027
(2020/09/01)
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- Introducing Oxo-Phenylacetyl (OPAc) as a Protecting Group for Carbohydrates
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A series of oxo-phenylacetyl (OPAc)-protected saccharides, with divergent base sensitivity profiles against benzoyl (Bz) and acetyl (Ac) were synthesized, and KHSO5/AcCl in methanol was identified as an easy, mild, selective, and efficient deprotecting reagent for their removal in the perspective of carbohydrate synthesis. Timely monitoring of AcCl reagent was supportive in both sequential and simultaneous deprotecting of OPAc, Bz, and Ac. The salient feature of our method is the orthogonal stability against different groups, its ease to generate different valuable acceptors using designed monosaccharides, and use of OPAc as a glycosyl donar.
- Kumar, Atul,Gannedi, Veeranjaneyulu,Rather, Suhail A.,Vishwakarma, Ram A.,Ahmed, Qazi Naveed
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p. 4131 - 4138
(2019/04/30)
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- Flavonoid glucosides from the flowers of Trollius chinensis Bunge
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Four new flavonoid glucosides, 2″-O-(6?-O-caffeoyl)-galactopyranosylvitexin (1), 2″-O-(6?-O-veratroyl)-galactopyranosylvitexin (2), 2″-O-(6?-O-feruloyl)-galactopyranosylorientin (3), 2″-O-(2?-O-methylbutyryl)-glucopyranosylisoswertisin (4), along with three known compounds were isolated from the flowers of Trollius chinensis Bunge. Their structures were determined by extensive spectroscopic analyses.
- Yan, Rui,Cui, Yida,Deng, Bowen,Bi, Jiayi,Zhang, Guogang
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p. 297 - 302
(2018/11/27)
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- Cycloartane and oleanane glycosides from the tubers of Eranthis cilicica
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Phytochemical analysis of the tubers of Eranthis cilicica was performed as part of our continuous study on the plants of the family Ranunculaceae, which resulted in the isolation of eleven new cycloartane glycosides (1-11) and one new oleanane glycoside (13), together with one known oleanane glycoside (12). The structures of the new compounds were determined by extensive spectroscopic analysis, including two-dimensional (2D) NMR, and enzymatic hydrolysis followed by either X-ray crystallographic or chromatographic analysis. The aglycone (1a) of 2 and its C-23 epimer (8a), and the oleanane glycosides (12 and 13) showed cytotoxic activity against HL-60 leukemia cells with IC50 values ranging from 10.6 μM to 101.6 μM. HL-60 cells were much more sensitive to 8a (IC50 14.8 μM) than 1a (IC50 101.1 μM), indicating that the C-23 configuration is associated with the cytotoxicity of these cycloartane derivatives. Compound 12 was revealed so as to partially induce apoptotic cell death in HL-60 cells, as was evident from morphology of HL-60 cells treated with 12.
- Watanabe, Kazuki,Mimaki, Yoshihiro,Fukaya, Haruhiko,Matsuo, Yukiko
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- Scrobiculosides A and B from the deep-sea sponge Pachastrella scrobiculosa
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Two new steroidal saponins, scrobiculosides A and B, were isolated from the deep-sea sponge Pachastrella scrobiculosa, collected at a depth of 200?m off Miura Peninsula, Japan. The aglycones of scrobiculosides A and B feature a vinylic cyclopropane and a ?24,25 exomethylene on the side chains, respectively. Both saponins have a common sugar moiety composed of β-d-galactopyranosyl-(1 → 2)-6-acetyl-β-d-glucopyranoside, with the exception of an acetyl group on C6″ in scrobiculoside A. Scrobiculoside A exhibited cytotoxicity against HL-60 and P388 cells, with IC50 values of 52 and 61?μM, respectively.
- Jomori, Takahiro,Shiroyama, Shuji,Ise, Yuji,Kohtsuka, Hisanori,Matsuda, Kenichi,Kuranaga, Takefumi,Wakimoto, Toshiyuki
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p. 814 - 819
(2019/05/15)
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- Synthesis of a 1,2-: Cis -indoxyl galactoside as a chromogenic glycosidase substrate
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A synthetically challenging 1,2-cis-indoxyl galactoside, X-α-galactoside, was first prepared in this study using a cyclic ketone indoxyl acceptor and a glycosyl trichloroacetimidate donor to produce an enol glycoside and a 4,6-O-di-tert-butylsilylene-protected galactosyl donor to complete the synthesis. The target compound shows enzyme activity in the presence of α-galactosidase.
- Nagata, Sakuto,Tomida, Hirotaka,Iwai-Hirose, Haruka,Tanaka, Hide-Nori,Ando, Hiromune,Imamura, Akihiro,Ishida, Hideharu
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p. 28241 - 28247
(2019/09/30)
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- Using the 3-Diethylaminobenzyl Group as a Photocage in Aqueous Solution
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We have demonstrated that the 3-diethylaminobenzyl (DEABn) photolabile protecting group (PPG) is an effective and structurally simple PPG for releasing molecules in aqueous environment. In general, the photoreaction is clean, and the released substrate and the PPG product, i.e., 3-diethylaminobenzyl alcohol, are obtained in high yield. The clean photoreaction can also be achieved under mild ambient conditions with sunlight, while the reactant is stable under indoor lighting. Release of two substrates from one PPG chromophore in aqueous solution has been demonstrated to be feasible. We have also compared the uncaging properties of the DEABn and the widely used o-nitrobenzyl (o-NB) group, given their comparable structural simplicity. With its clean and efficient photochemical reaction, DEABn should find wide applications, including in the basic and applied research areas where o-NB and its various derivatives are widely used.
- Ding, Xiong,Wang, Pengfei
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p. 7459 - 7466
(2018/05/29)
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- Indium- and Zinc-Mediated Acyloxyallylation of Protected and Unprotected Aldotetroses - Revealing a Pronounced Diastereodivergence and a Fundamental Difference in the Performance of the Mediating Metal
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The acyloxyallylation of unprotected aldoses was first demonstrated more than a decade ago as a potentially elegant two-carbon homologation of reducing sugars (upon ozonolysis); however, its application in real case syntheses remained scarce. Following up on such a successful showcase and to answer several pending questions about this attractive transformation, we engaged in an in depth methodological reinvestigation. The epimeric tetroses l-erythrose and d-threose in unprotected and protected form were successfully applied to the indium and also zinc-mediated acyloxyallylation, with the latter being a first for an unprotected sugar. The investigation largely benefited from the choice of these more exotic starting materials as it allowed unambiguous identification/quantification of the hexose-products which are available as authentic reference materials. The observed diastereoselectivities indicate a strong substrate control (stereochemistry at O2), and the influence of the reagent's structure on the selectivity was investigated in great detail. A strong facial diastereodivergence between related protected and unprotected structures was demonstrated and an unexpected, pronounced principle difference in performance between indium and zinc was revealed.
- Draskovits, Markus,Stanetty, Christian,Baxendale, Ian R.,Mihovilovic, Marko D.
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p. 2647 - 2659
(2018/03/09)
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- Steroidal constituents from roots and rhizomes of Smilacina japonica
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Four new steroidal constituents (1–4) along with two known steroidal glycosides (5 and 6) were isolated from the roots and rhizomes of Smilacina japonica. Analysis of their physicochemical properties and spectroscopic profiles identified the compounds as
- Cui, Yuwen,Yang, Xinjie,Zhang, Dongdong,Li, Yuze,Zhang, Li,Song, Bei,Yue, Zhenggang,Song, Xiaomei,Tang, Haifeng
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- RADIOLABELED BETA-GALACTOSIDASE SUBSTRATE FOR PET IMAGING OF SENESCENCE
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The present invention relates to novel compounds useful for visualizing cell sen es c en ce in vitro and in vivo, the preparation of said compounds and their use. In particular, the present invention pertains to novel hexose and particularly galactose derivatives which are useful as senescence tracers in vitro and in vivo. In a particular embodiment, the compounds have the formulas wherein Z is a radioactive detectable label, a radioactive therapeutic residue, a chelator coordinating a radioactive detectable label or a chelator coordinating a radioactive therapeutic residue.
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- Measuring Bacterial Glycosyl Hydrolase Activity with a Soluble Capture Probe by Mass Spectrometry
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A solution-phase enzymatic assay has been developed to track bacterial glycosyl hydrolase activity by surface-assisted MALDI-TOF mass spectrometry. Lactose was equipped with an azide-functionalized linker and was supplemented to bacterial cultures as an artificial substrate for bacterial β-galactosidase enzyme. The azide linked glycoside probe was then covalently captured on an alkyne-functionalized indium tin oxide sample plate via a bio-orthogonal copper-catalyzed azide alkyne cycloaddition (CuAAC). The noncovalent immobilization of the alkyne capture tag via hydrophobic interactions on the ITO-sample plate allowed the analysis of the probe conjugate by surface-based mass spectrometry. The ratio of digested to nondigested lactose probe was then employed as a measure for bacterial hydrolase activity, which correlated well with bacterial growth measured by optical density. In addition, we established in a proof of concept experiment that the setup was well suited to identify antibiotic susceptibility of bacterial strains with a performance comparable to current state-of-the-art methods. While the proof of concept version is limited to the identification of a single enzyme activity, we envisage that the use of multiple substrate probes in a multiplexed version will allow the quantification of various glycosyl hydrolase activities with clinical relevance in a single experiment.
- Serna, Sonia,Ercibengoa, María,Marimón, Jose María,Reichardt, Niels-Christian
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p. 12536 - 12543
(2018/11/23)
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- New triterpenoid saponins from the herb hylomecon japonica
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Background: Hylomecon japonica, a plant of the Papaveraceae family which is well-known for the alkaloids they produce, is a perennial plant widely distributed in the northeast, central and east regions of China. Although a variety of chemical constituents, including alkaloids, flavonoids, and megastigmoids, have been isolated from H. japonica, the investigation of saponins in H. japonica has not been reported until now. Methods: Various separation techniques, including polyporous resin column chromatography, silica gel column chromatography and hemi-preparative HPLC were applied to the isolation of triterpenoid saponins, and chemical methods such as acid hydrolysis and spectroscopic methods including HRESIMS and NMR were applied to their structure elucidation, and the XTT reduction method was used to assay cytotoxicity. Results: Two new triterpenoid saponins, named hylomeconoside A (1) and B (2) which were identified as 3-O-β-D-galactopyranosyl-(1→2)-β-D-glucuronopyranosyl-gypsogenin-28-O-β-D-xylopyranosyl- (1→3)-β-D-xylopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→2)-β-D-quinovopyranoside (1) and 3-O-β-D-galactopyranosyl-(1→2)-β-D-glucuronopyranosyl-gypsogenin-28-O-β-D-xylopyranosyl- (1→3)-β-D-xylopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranoside (2), and two known triterpenoid saponins identified as dubioside C (3) and lucyoside P (4) on the basis of spectroscopic and chemical evidence, were isolated from H. japonica. Compound 1 exhibited moderate cytotoxicity on MGC-803 and HL-60 cells, with IC50 values of 43.8 and 32.4 μg.mL-1, respectively. Conclusions: Compounds 1 and 2 are new saponins, and 1 is considered to be one of the antitumor principles in this plant. This is the first time that triterpenoid saponins have been isolated from plants of the Papaveraceae family.
- Qu, Yan-Fei,Gao, Jing-Yu,Wang, Jing,Geng, Yan-Mei,Zhou, Yu,Sun, Cheng-Xin,Li, Fei,Feng, Lei,Yu, Meng-Juan,Wang, Guang-Shu
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- Steroidal glycosides from Convallaria majalis whole plants and their cytotoxic activity
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Phytochemical examination of Convallaria majalis (Liliaceae) whole plants yielded 15 steroidal glycosides (1-15), including nine new compounds (4-6, 10-15) with a lycotetrose unit. The structures of the new compounds were determined using two-dimensional Nuclear magnetic resonance (NMR) analyses and chemical methods. The isolated compounds were evaluated for cytotoxicity against HL-60 human promyelocytic leukemia cells, A549 human lung adenocarcinoma cells, and HSC-4 and HSC-2 human oral squamous cell carcinoma cell lines. Of these, (25S)-spirost- 5-en-3β-yl O-β-D-glucopyranosyl-(1→2)-O-[β-D-xylopyranosyl-(1→3)]-O-β-D-glucopyranosyl- (1→4)-β-D-galactopyranoside (1) exhibited cytotoxic activity against HL-60, A549, HSC-4, and HSC-2 cells with IC50 values ranging from 0.96 to 3.15 μM. The corresponding furostanol glycoside of 1, (25S)-26-[(β-D-glucopyranosyl)oxy]-22α-hydroxyfurost-5-en-3β-yl O-β-D-glucopyranosyl-(1→2)-O- [β-D-xylopyranosyl-(1→3)]-O-β-D-glucopyranosyl-(1→4)-β-D-galactopyranoside (8), was cytotoxic to the adherent cell lines of A549, HSC-4, and HSC-2 cells with IC50 values of 2.97, 11.04, and 8.25 μM, respectively. The spirostanol lycotetroside (1) caused necrotic cell death in A549 cells in a dosedependent manner. Alternatively, the furostanol lycotetroside (8) induced apoptotic cell death in A549 cells in a time-dependent manner, as was evident by morphological observations and flow cytometry analyses.
- Matsuo, Yukiko,Shinoda, Daisuke,Nakamaru, Aina,Kamohara, Kuni,Sakagami, Hiroshi,Mimaki, Yoshihiro
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- Cytotoxic and hypoglycemic activity of triterpenoid saponins from camellia oleifera abel. Seed pomace
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One new and three known triterpenoid saponins were isolated and identified from Camellia oleifera seeds through IR, NMR, HR-ESI-MS and GC-MS spectroscopic methods, namely oleiferasaponin A3, oleiferasaponin A1, camelliasaponin B
- Di, Tai-Mei,Yang, Shao-Lan,Du, Feng-Yu,Zhao, Lei,Xia, Tao,Zhang, Xin-Fu
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- Efficient and green approach for the complete deprotection of O-acetylated biomolecules
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A simple, efficient and mild strategy for the complete O-deacetylation of different per-acetylated biomolecules in aqueous media has been described. Different lipases were tested but only the commercial Amano lipase A from Aspergillus Niger catalyzed the complete deprotection of peracetylated α-glucose to glucose in excellent yield. The experimental conditions were tested, in particular the pH effect. The reaction was performed at different pHs considering the only enzymatic process was evaluated at pH 5 and the combination of enzymatic and chemical migration process was evaluated at higher pHs. Finally pH 7 and 25 °C were selected as best conditions. Thus this lipase fully hydrolyzed different peracetylated α-glycopyranosides (glucose, mannose, glucal, galactal) with >99% yields, whereas very good deprotecting yields (75-80%) were achieved for different acetylated β-glycopyranosides (galactose, ribofuranose) under these mild conditions. This strategy was successfully extended to the fully O-selective deprotection of acetylated nucleosides where >99% yield was rapidly obtained. No selectivity was observed for the N-deacetylation in amino acids and peptides.
- Dunne, Anthony,Palomo, Jose M.
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p. 88974 - 88978
(2016/10/03)
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- Isolation, structure elucidation and DFT study on two novel oligosaccharides from yak milk
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Two novel oligosaccharides were isolated from yak milk. The milk was processed by the method of Kobata and Ginsberg involving deproteination, centrifugation and lyophilization followed by gel filtrate chromatography acetylation and silica gel column chromatography of derivatized oligosaccharides while their homogeneity was confirmed by HPLC. The structures of these isolated oligosaccharides were elucidated by chemical transformation, chemical degradation, 1H, 13C NMR, 2D NMR (COSY, TOCSY and HSQC) and mass spectrometry. The geometry of compound A (Bosiose) and B (Bovisose) have been optimized at B3LYP method and 6-311 + G(d,p) basis set. The difference between the energies of A and B is 1.269 a.u. or 796.309 kcal/mol.
- Singh, Meenakshi,Kumar, Alok,Srivastava, Gaurav,Deepak, Desh,Singh
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- α -Amylase and α -Glucosidase Inhibitory Saponins from Polyscias fruticosa Leaves
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Three bisdesmosidic saponins 3-O-[β-D-glucopyranosyl-(1 → 4)-β-D-glucuronopyranosyl] oleanolic acid 28-O-β-D-glucopyranosyl ester (1), polyscioside D (2), and 3-O- { β -D-glucopyranosyl-(1 → 2)-[β-D-glucopyranosyl-(1 → 4)]-β-D- g l u c u r o n o p y r a n o s y l } oleanolic acid 28-O-β-D-glucopyranosyl-(1 → 2)-β-D-galactopyranosyl ester (3) were isolated from a methanol extract of Polyscias fruticosa (L.) Harms leaves. Compound 1 was obtained as a main constituent and compound 3 was reported for the first time and named as polyscioside I. Saponin 1 inhibited porcine pancreas α-amylase and yeast α-glucosidase activities while 2 and 3 were inactive. Synergistic inhibitory effect on α-amylase was observed from the combination of low concentrations of 1 and acarbose. The findings suggest the use of P. fruticosa and its major saponin 1 for the prevention and treatment of diabetes and its complications.
- Hanh, Tran Thi Hong,Dang, Nguyen Hai,Dat, Nguyen Tien
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- Enhanced basicity of Ag2O by coordination to soft anions
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In Ag2O-mediated benzylation, the addition of a catalytic amount of KI can greatly improve reactivity. This is usually attributed to the formation of a more reactive iodo-substituted electrophile. However, our studies show this to be due to the enhanced basicity of Ag2O through coordination of soft iodide anions to the silver atom, and show KI to be an initiator. A catalytic amount of Ag2O and NaBr can catalyze transesterification reactions, indicating the enhanced basicity of Ag2O by bromide. We believe that this is a general effect for metal oxides and soft anions, applicable to a wider range of organic reaction systems. All your base belongs to us: In Ag2O-mediated benzylation, the addition of a catalytic amount of KI can greatly improve reactivity. Our studies show this to be attributable to the enhanced basicity of Ag2O through coordination of soft iodide anions to the silver atom, and show KI to be an initiator. Thus, NaBr as an initiator combined with Ag2O has been successfully used to catalyze transesterification reactions.
- Ren, Bo,Wang, Meiyan,Liu, Jingyao,Ge, Jiantao,Dong, Hai
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p. 761 - 765
(2015/03/04)
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- Zemplén transesterification: A name reaction that has misled us for 90 years
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We demonstrated that using NaOH and NaOMe in methanol for deacylation are identical, indicating that the Zemplén condition has been misleading us for almost 90 years. The traditional base-catalyzed mechanism cannot be used to explain our results. We propose that H-bond complexes play key roles in the base-catalyzed process, explaining why deacylation in methanol can be catalyzed by hydroxide.
- Ren, Bo,Wang, Meiyan,Liu, Jingyao,Ge, Jiantao,Zhang, Xiaoling,Dong, Hai
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supporting information
p. 1390 - 1394
(2015/03/18)
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- New triterpenoid glycosides from the roots of camellia oleifera abel
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Five new triterpenoid saponins, oleiferosides I-M (1-5, resp.) were isolated from the roots of Camellia oleifera Abel. Their structures were elucidated by a combination of 1D- and 2D-NMR spectroscopy, mass spectrometry, and chemical methods. All the compounds were identified as oleanane-type saponins with sugar moieties linked to C(3) of the aglycone. In addition, cytotoxic activities of these saponins were evaluated against four human tumor cell lines (A549, B16, BEL-7402, and MCF-7) by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) in vitro assay. All of the compounds showed significant cytotoxic activities against the tested cell lines.
- Li, Xia,Zhao, Jianping,Li, Xiaoran,Liu, Yanli,Xu, Qiongming,Khan, Ikhlas A.,Yang, Shilin
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p. 496 - 508
(2015/04/27)
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- A novel, efficient and sustainable strategy for the synthesis of α-glycoconjugates by combination of a α-galactosynthase and a green solvent
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Glycosynthases are becoming important enzymatic tools for the synthesis of oligosaccharides. Herein, we explore for the first time the synthesis of α-glycoconjugates using a α-glycosynthase in green solvents. Using this biocatalyst, β-Gal-N3 as donor, pNP-Glc and pNP-Man as acceptors, and green co-solvents we obtained high yields and excellent selectivities in the synthesis of α-glycoconjugates. In addition, reaction scale-up is feasible and co-solvent can be recovered and reused, increasing the sustainability of the reaction process. The results demonstrate that the combination of a glycosynthase and a green solvent is a promising alternative for the synthesis of glycoconjugates. The non-hydrolytic capability of this enzyme on the product obtained is a key feature that can be expanded to other glycosynthases.
- Bayón,Moracci,Hernáiz
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p. 55313 - 55320
(2015/07/07)
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- Catalytic isomerization of allyl functionalities in water by hexaaquaruthenium(II) tosylate
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The water-soluble coordination compound hexaaquaruthenium(II) p-toluene sulfonate (1) catalyzes olefin isomerization that makes it a useful catalyst in unmasking allyl ether and ester protecting groups in water. Allyl ethers of alcohols and acetic acid allyl ester are readily converted to the corresponding alcohols and acid in a catalytic fashion with compound 1 in water (50°C). A mechanistic investigation on ethylene glycol monoallyl ether reveals the intermediate vinyl ether resulting from olefn isomerization (ΔH? = 19.0 (±0.4) kcal/mol). This is followed by hydrolysis to the final ethylene glycol that is promoted by 1. This "one-pot" reaction provides a new useful coordination compound as a deprotection reagent in synthetic organic chemistry.
- Kuo, Louis Y.,Delaney, Frances E.
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p. 335 - 339
(2015/08/18)
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- Improving properties of a novel β-galactosidase from Lactobacillus plantarum by covalent immobilization
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A novel β-galactosidase from Lactobacillus plantarum (LPG) was over-expressed in E. coli and purified via a single chromatographic step by using lowly activated IMAC (immobilized metal for affinity chromatography) supports. The pure enzyme exhibited a high hydrolytic activity of 491 IU/mL towards o-nitrophenyl β-D-galactopyranoside. This value was conserved in the presence of different divalent cations and was quite resistant to the inhibition effects of different carbohydrates. The pure multimeric enzyme was stabilized by multipoint and multisubunit covalent attachment on glyoxyl-agarose. The glyoxyl-LPG immobilized preparation was over 20-fold more stable than the soluble enzyme or the one-point CNBr-LPG immobilized preparation at 50°C. This β-galactosidase was successfully used in the hydrolysis of lactose and lactulose and formation of different oligosaccharides was detected. High production of galacto-oligosaccharides (35%) and oligosaccharides derived from lactulose (30%) was found and, for the first time, a new oligosaccharide derived from lactulose, tentatively identified as 3′-galactosyl lactulose, has been described.
- Benavente, Rocio,Pessela, Benevides C.,Curiel, Jose Antonio,De Las Rivas, Blanca,Mu?oz, Rosario,Guisán, Jose Manuel,Manche?o, Jose M.,Cardelle-Cobas, Alejandra,Ruiz-Matute, Ana I.,Corzo, Nieves
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p. 7874 - 7889
(2015/05/20)
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- Characterization and antitumor activities of a water-soluble polysaccharide from Ampelopsis megalophylla
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Abstract A water-soluble polysaccharide named as AMP was isolated and purified from the leaves of Ampelopsis megalophylla by DEAE-52 Cellulose and Sephadex G-100 column chromatography. AMP had an average molecular weight of about 8.4 × 104 Da and was composed of galactose (Gal), mannose (Man), glucose (Glc), arabinose (Ara), and rhamnose (Rha) in a molar ratio of 2.7:1.6:1.1:0.6:0.3. After 10 days of AMP (50, 100, and 200 mg/kg) treatment once daily in tumor-bearing mice, AMP oral administration could inhibit the growth of transplantable Sarcoma 180 (S180) tumor in mice and increase the spleen index and body weight. Furthermore, AMP also promote splenocytes' proliferation induced by concanavalin A (ConA) and lipopolysaccharide (LPS), strengthen peritoneal macrophages to devour neutral red and increase the production of interleukin-2 (IL-2), tumor necrosis factor-alpha (TNF-α), and interferon-gamma (IFN-γ) in serum. These results suggest that AMP had clear antitumor activity, which might be related to its regulation of immune function in mice.
- Xie, Xianfei,Wang, Jianwu,Zhang, Hanping
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- Method for Preparing 3,6-Anhydro-L-Galactose, And Use Thereof
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The present invention relates to a method for preparing 3,6-anhydro-L-galactose, and use thereof. More specifically, 3,6-anhydro-L-galactose, which is a monosaccharide constituting agar, is produced in a high yield through chemical and enzymatic methods, and the physiological activities thereof such as whitening, moisturizing, antioxidant, anti-inflammatory activities and the like are displayed, thereby enabling industrial use thereof.
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Paragraph 0107; 0108
(2015/09/22)
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- Structure and genetics of biosynthesis of the glycosyl phosphate-containing O-polysaccharide of Escherichia coli O160
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On mild acid degradation of the lipopolysaccharide of Escherichia coli O160, the O-polysaccharide was cleaved by acid-labile glycosyl phosphate linkages in the main chain. The resultant oligosaccharide and the alkali-treated lipopolysaccharide were studied by sugar analysis along with 1H and 13C NMR spectroscopies, and the following structure of the branched pentasaccharide repeating unit of the O-polysaccharide was established:β-D-G1cp The O-antigen gene cluster of E.coli O160 was found to be consistent with the O-polysaccharide structure established.
- Perepelov, Andrei V.,Guo, Xi,Senchenkova, Sof'ya N.,Shashkov, Alexander S.,Knirel, Yuriy A.
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- Spider silk capsules as protective reaction containers for enzymes
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Spider silk fibres are well known for their high tensile strength in combination with high elasticity. Based on the possibility of recombinant production of spider silk proteins, technical applications of spider silk materials are nowadays feasible. The engineered recombinant spider silk protein eADF4(C16) is based on the sequence of ADF4 (Araneus diadematus fibroin), one out of at least three proteins of the dragline silk of the European garden spider A. diadematus. The protein eADF4(C16) can be processed into different morphologies. Here, capsules of eADF4(C16) are assembled at an oil/water interface. These microcapsules are mechanically stable and can be used as a transport system for higher molecular weight compounds such as enzymes or chemical catalysts. Further, they can be regarded as a small enclosed reaction chamber with a semi-permeable membrane. Reactions can be initiated by diffusion of the reactants through the silk membrane. The eADF4(C16) capsules protect the enzyme β-galactosidase, used as model, against proteolysis. Functional α-complementation of β-galactosidase visualizes the controllable activation of an enzyme within such spider silk capsule, highlighting the broad applicability thereof as reaction containers, e.g., for enzymes. Capsules made of recombinant spider silk proteins are suitable as reaction containers for various encapsulates including enzymes. Since low molecular weight substances can freely diffuse through the silk membrane while high molecular weight substances are retained, a specific triggering of reactions is possible. The capsules further protect encapsulates from proteolysis.
- Bluem, Claudia,Nichtl, Alfons,Scheibel, Thomas
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p. 763 - 768
(2014/03/21)
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- Two new glycosides from Duboscia macrocarpa Bocq.
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Two new compounds namely dubosciasides A (1) and B (2) were isolated from stem bark of Duboscia macrocarpa Bocq. together with three known flavonoids. Their structures were determined by spectroscopic methods including one- and two-dimensional NMR, EIMS and HRESIMS. The new compounds were identified as 6-C-β-d-apiofuranosyl-(1 → 4)-β-d-galactopyranosylnaringetol (1) and 1-O-α-l-rhamnopyranosyl-(1 → 4)-β-d-xylopyranosyl-3,4,5-trimethoxyphenol (2).
- Tchuendem, Marguerite H.K.,Douanla, Pascal D.,Tabopda, Turibio K.,Tchinda, Alembert T.,Tamze, Véronique,Nkengfack, Augustin E.,Abegaz, Berhanu M.,Connolly, Joseph D.
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- Acidolysis-based component mapping of glycosaminoglycans by reversed-phase high-performance liquid chromatography with off-line electrospray ionization-tandem mass spectrometry: Evidence and tags to distinguish different glycosaminoglycans
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Diverse monosaccharide analysis methods have been established for a long time, but few methods are available for a complete monosaccharide analysis of glycosaminoglycans (GAGs) and certain acidolysis- resistant components derived from GAGs. In this report, a reversed-phase high-performance liquid chromatography (RP-HPLC) method with pre-column 1-phenyl-3-methyl-5-pyrazolone (PMP) derivatization was established for a complete monosaccharide analysis of GAGs. Good separation of glucosamine/ mannosamine (GlcN/ManN) and glucuronic acid/iduronic acid (GlcA/IdoA) was achieved. This method can also be applied to analyze the acidolysis-resistant disaccharides derived from GAGs, and the sequences of these disaccharides were confirmed by electrospray ionization-collision-induced dissociation- tandem mass spectrometry (ESI-CID-MS/MS). These unique disaccharides could be used as markers to distinguish heparin/heparan sulfate (HP/HS), chondroitin sulfate/dermatan sulfate (CS/DS), and hyaluronic acid (HA).
- Zhu, He,Chen, Xuan,Zhang, Xiao,Liu, Lili,Cong, Dapeng,Zhao, Xia,Yu, Guangli
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- Thotneosides A, B and C: Potent antioxidants from nepalese crude drug, leaves of aconogonon molle
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Three new glycosides: thotneoside A (quercetin 3-O-(6δ-O- phenylacetyl)-β-D-galactopyranoside) (1), thotneoside B (quercetin 3-O-(6δ-O-phenylacetyl)-β-D-glucopyranoside) (2) and thotneoside C (3-methyl- 2-butenoic acid 1-O-β-D-glucopyranoside) (3), together with nine known compounds; quercetin (4), quercetin 3-O-β-D-galactopyranoside (5), quercetin 3-O-(6δ-O-galloyl)-β-D-galactopyranoside (6), quercetin 3-O-β-Dgalacturonopyranoside (7), quercetin 3-O-β-D- glucuronopyranoside (8), quercetin 3-O-a-L-rhamnopyranoside (9), rutin (10), quercetin 3-O-a-L-arabinopyranoside (11) and 2,4,6-trihydroxyacetophenone 2-O-β-Dglucopyranoside (12) have been isolated from the shade dried leaves of Aconogonon molle, commonly known as Thotne in Nepal. The structures were elucidated on the basis of chemical and spectroscopic methods. All of these compounds were isolated for the first time from A. molle and their in vitro antioxidant activity was evaluated by 1,1-diphenyl-2-picrylhydrazyl (dPPH) free radical scavenging assay. Quercetin (4) and its glycosides (1-2, 5-11) showed potent free radical scavenging activity.
- Joshi, Khem Raj,Devkota, Hari Prasad,Watanabe, Takashi,Yahara, Shoji
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p. 191 - 195
(2014/03/21)
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- A new flavonol glycoside from the aerial part of Rudbeckia laciniata
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The phytochemical investigation of Rudbeckia laciniata L. obtained a new flavonol glycoside (1), together with four flavonol glycosides (2-5) and eight quinic acid derivatives (6-13). The structure was elucidation by means of spectroscopic methods and chemical evidence. The isolated compounds were tested for cytotoxicity against four human tumor cell lines in vitro using the sulforhodamine B bioassay.
- Lee, Seung Young,Shin, Young June,Choi, Sang Un,Lee, Kang Ro
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p. 834 - 838
(2014/08/05)
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- New mono- and bisdesmosidic triterpene glycosides from Pittosporum angustifolium Lodd.
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Fifteen new mono- and bisdesmosidic triterpene saponins, named pittangretosides J, K, M, Q-Z, A1, and B1, along with three known compounds were isolated from the leaves of Pittosporum angustifolium. By spectroscopic, mass spectrometric and chemical evidence, their structures were established as glycosides of A1- and R1-barrigenol, barringtogenol C and camelliagenin A backbones.
- B?cker, Christian,Jenett-Siems, Kristina,Siems, Karsten,Wurster, Martina,Bodtke, Anja,Niedermeyer, Timo H.J.,Lindequist, Ulrike
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p. 1026 - 1044
(2015/06/16)
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- Bioactive secondary metabolites from tecomella undulata
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Chromatographic purification of the methanolic extract of Tecomella undulata yielded a new flavonoid glycoside; kaempferol-3-O-β-D-[3 ,4di-p-E -coumaroyl-α-L-rhamnosyl(1→6)] galactoside (1 ), two new megastigmanes; (6R 7Z )-9,10-dihydroxy-4,7-megastigmadien-3-one (2) and (6E )-9,10-dihydroxy-4,6-megastigmadien-3-one (3) along with three known compounds; (6R 9S)-9,10-dihydroxy-4-megastigmaen-3-one (4) quercetin-3-galactoside (5) and 3′-dimethoxy-5,6,4′-trihydroxyflavon (6). All the isolates 1-6 were characterized by the combination of 1D (1H, 13C), 2D (COSY, HSQC and HMBC) NMR data and high resolution mass spectrometric analysis. In antibacterial assay, compound 1 showed moderate inhibitory activity against Escherichia coli and Salmonalla typhi.
- Ahmad, Shabir,Musaddiq, Sara,Saleem, Muhammad,Riaz, Naheed,Fatima, Sundas,Yaqoob, Asma,Jabbar, Abdul,Nasim, Faiz-Ul-Hassan
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p. 1122 - 1128
(2015/01/30)
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- Rare syringyl acylated flavonol glycosides from the aerial parts of Leonurus japonicus Houtt.
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Five new syringyl acylated flavonol glycosides, named leonurusoides A (1), B (2), C (3), D (4), and E (5), together with one known one 6 were obtained from the aerial parts of Leonurus japonicus. Their structures were elucidated by chemical and spectroscopic methods (UV, IR, HRESI-TOF-MS, 1D and 2D NMR). Compounds 1-6 showed triglyceride (TG) accumulation inhibitory effects in free fatty acid-induced HepG2 cells.
- Zhang, Yi,Deng, Shen,Qu, Lu,An, Ya-Ting,Wu, Chun-Hua,Han, Li-Feng,Gao, Xiu-Mei,Wang, Tao
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p. 2967 - 2977
(2013/05/22)
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