- Synthesis and biological evaluation of 3β-O-neoglycosides of caudatin and its analogues as potential anticancer agents
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In order to study the structure–activity relationship (SAR) of C21-steroidal glycosides toward human cancer cell lines and explore more potential anticancer agents, a series of 3β-O-neoglycosides of caudatin and its analogues were synthesized. The results revealed that most of peracetylated 3β-O-monoglycosides demonstrated moderate to significant antiproliferative activities against four human cancer cell lines (MCF-7, HCT-116, HeLa, and HepG2). Among them, 3β-O-(2,3,4-tri-O-acetyl-β-L-glucopyranosyl)-caudatin (2k) exhibited the highest antiproliferative activity aganist HepG2 cells with an IC50 value of 3.11 μM. Mechanical studies showed that compound 2k induced both apoptosis and cell cycle arrest at S phase in a dose dependent manner. Overall, these present findings suggested that glycosylation is a promising scaffold to improve anticancer activity for naturally occurring C21-steroidal aglycones, and compound 2k represents a potential anticancer agent deserved further investigation.
- Li, Xiao-San,Chen, Tang-Ji,Xu, Zhi-Peng,Long, Juan,He, Miao-Ying,Zhan, He-Hui,Zhuang, Hai-Cai,Wang, Qi-Lin,Liu, Li,Yang, Xue-Mei,Tang, Jin-Shan
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- Synthesis and antimicrobial studies of novel n-glycosyl hydrazino carbothioamide
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In view of applications of N-glycosylated compounds in medicinal chemistry and in many other ways, herein the synthesis of novel N-glycosyl hydrazino carbothioamides is reported. New N-glycosyl hydrazino carbothioamides were synthesized by the condensation of per-O-acetyl glycosyl isothiocyanate with different aromatic hydrazides. The newly synthesized compounds were characterized by using the IR, 1H NMR and mass spectral studies. Antimicrobial evaluation of the synthesized N-glycosyl hydrazino carbothioamide was also examined. Antimicrobial activities of the synthesized compound were evaluated against bacteria E. coli, P. aeruginosa, S. aureus, S. pyogenus and fungi C. albicans, A. niger and A. clavatus. All the N-glycosyl hydrazino carbothioamides exhibit promising antimicrobial activity.
- Nayak, Riddhi A.,Mangte, Anvita D.
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p. 127 - 131
(2021/01/06)
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- Halogenation and anomerization of glycopyranoside by TESH/bromine and BHQ/bromine
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Treatment of peracetylated glycosides and β-isopropyl glycosides with halogen in the presence of TESH and BHQ has been found to result in the halogenation and the anomerization, respectively. Peracetylatedglycosides treaded with I2/TESH or Br2/TESH leading tothe formation of corresponding glycosyl halides, and b-isopropyl glycosidesreacted with Br2/BHQ resulting in the formation of a-glycosides. The anomerizationof glycosidic bond was considered to be catalyzed by in situ formation of hydrogenbromide from the mixing of Br2/BHQ.
- Xu, Lai,Luo, Chin-Hung,Chen, Chien-Sheng
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p. 315 - 321
(2020/07/13)
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- Chemical synthesis of 5’-β-glycoconjugates of vitamin B6
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Various 5’-β-saccharides of pyridoxine, namely the mannoside, galactoside, arabinoside, maltoside, cellobioside and glucuronide, were synthesized chemically according to KOENIGS-KNORR conditions using α4,3-O-isopropylidene pyridoxine and the respective acetobromo glycosyl donors with AgOTf (3.0 eq.) and NIS (3.0 eq.) as promoters at 0 °C. Furthermore, 5’-β-[13C6]-labeled pyridoxine glucoside (PNG) was prepared starting from [13C6]-glucose and pyridoxine. Additionally, two strategies were examined for the synthesis of 5’-β-pyridoxal glucoside (PLG).
- Bachmann, Thomas,Schnurr, Christian,Zainer, Laura,Rychlik, Michael
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supporting information
(2020/02/15)
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- Controlling the Kinetics of Self-Reproducing Micelles by Catalyst Compartmentalization in a Biphasic System
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Compartmentalization of reactions is ubiquitous in biochemistry. Self-reproducing lipids are widely studied as chemical models of compartmentalized biological systems. Here, we explore the effect of catalyst location on copper-catalyzed azide-alkyne cycloadditions which drive the self-reproduction of micelles from phase-separated components. Tuning the hydrophilicity of the copper-ligand complex, so that hydro-phobic or -philic catalysts are used in combination with hydro-philic and -phobic coupling partners, provides a wide range of reactivity patterns. Analysis of the kinetic data shows that reactions with a hydrophobic catalyst are faster than with a hydrophilic catalyst. Diffusion-ordered spectroscopy experiments suggest compartmentalization of the hydrophobic catalyst inside micelles while the hydrophilic catalyst remains in the bulk aqueous phase. The autocatalytic effects observed can be tuned by varying reactant structure and coupling a hydrophilic alkyne and hydrophobic azide results in a more pronounced autocatalytic effect. We propose and test a model that rationalizes the observations in terms of the phase behavior of the reaction components and catalysts.
- Post, Elias A. J.,Fletcher, Stephen P.
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p. 2741 - 2755
(2019/02/26)
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- Design, synthesis of oleanolic acid-saccharide conjugates using click chemistry methodology and study of their anti-influenza activity
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The development of entry inhibitors is an emerging approach to the inhibition of influenza virus. In our previous research, oleanolic acid (OA) was discovered as a mild influenza hemagglutinin (HA) inhibitor. Herein, as a further study, we report the preparation of a series of OA-saccharide conjugates via the CuAAC reaction, and the anti-influenza activity of these compounds was evaluated in vitro. Among them, compound 11b, an OA-glucose conjugate, showed a significantly increased anti-influenza activity with an IC50 of 5.47 μM, and no obvious cytotoxic effect on MDCK cells was observed at 100 μM. Hemagglutination inhibition assay and docking experiment indicated that 11b might interfere with influenza virus infection by acting on HA protein. Broad-spectrum anti-influenza experiments showed 11b to be robustly potent against 5 different strains, including influenza A and B viruses, with IC50 values at the low-micromole level. Overall, this finding further extends the utility of OA-saccharide conjugates in anti-influenza virus drug design.
- Su, Yangqing,Meng, Lingkuan,Sun, Jiaqi,Li, Weijia,Shao, Liang,Chen, Kexuan,Zhou, Demin,Yang, Fan,Yu, Fei
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- New water soluble glycosides of 11-keto-β-boswellic acid: A paradigm
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Though several glycosides of various triterpenes are known, but surprisingly no boswellic acid glycosides are reported so far. With a view to make water soluble boswellic acids, prepared glycosides of 11-keto boswellic acid for the first time. Naturally occurring boswellic acids which are anti-inflammatory agents are lipophylic in nature and thus, become a limiting factor in terms of their bioavailability. Among boswellic acids, 11-keto-β-boswellic acid is found to exhibit superior biological activity and hence successfully prepared its glucosyl and maltosyl derivatives viz., 11-keto-β-boswellic acid-24-O-β-D-glucopyranoside (9) and 11-keto-β-boswellic acid-24-O-α-D-glucopyranosyl-(1?→?4)-β-D-glucopyranoside (15) which are water soluble. Both these compounds are soluble in water to the extent of 10% (w/w) which is very significant.
- Manjunath,Shenvi, Suvarna,Raja,Reddy, G. Chandrasekara
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p. 154 - 161
(2017/10/05)
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- Self-reproducing micelles coupled to a secondary catalyst
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We report a physical autocatalytic system where micelles self-reproduce via a copper-catalyzed azide-alkyne cycloaddition in a biphasic reaction mixture. The coupling of a secondary catalyst to an autocatalytic cycle opens up new opportunities to control and probe autocatalytic processes.
- Post, Elias A. J.,Bissette, Andrew J.,Fletcher, Stephen P.
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supporting information
p. 8777 - 8780
(2018/08/07)
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- Preparation and functional analysis of gossypols having two carbohydrate appendages with enaminooxy linkages
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We developed new gossypol (Gos)-based glycoconjugates through dehydration condensation of native Gos and chemically modified glycosides having aminooxy groups. The resultant glycoconjugates (glycoGos) were resistant to hydrolysis, although they were light-sensitive and slowly decomposed even under indoor lighting. The glycoGos also exhibited improved water solubility compared with native Gos, but their saturated concentrations in water were still low (6.4–17 μM), due to their hydrophobic naphthyl rings. We also carried out WST-8 assays to assess the anticancer activity of the glycoGos on DLD-1 and HepG2 cells and found that the glycoGos having β-lactosides and having β-galactosides (specific ligands for asialoglycoprotein receptors) showed enhanced anticancer activity on HepG2 cells.
- Amano, Yoshitsugu,Nakamura, Masaki,Shiraishi, Shinya,Chigira, Naoto,Shiozawa, Nobuya,Hagio, Masahito,Yano, Tomohiro,Hasegawa, Teruaki
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- Evaluation of anti α-d-Glc: P -(1→4)-α-d-Glc p (GAGA4) IgM antibodies as a biomarker for multiple sclerosis
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The correct diagnosis of multiple sclerosis (MS) remains challenging due to the complex pathophysiological and clinical characteristics of the disease. Consequently, there has been immense interest in finding a non-invasive diagnostic test for MS. Recent studies found that serum anti-α-d-Glcp-(1→4)-α-d-Glcp (GAGA4) IgM antibodies were upregulated in MS patients, and this finding led to the development of a commercial diagnostic test (gMS Dx test), although the test has poor selectivity and has not been independently validated. Herein, we developed an enzyme-linked immunosorbent assay (ELISA) to evaluate the use and reliability of several anti-glucose IgM antibodies, including those against GAGA4, as diagnostic biomarkers for MS. In contrast to previous studies, our results show that serum anti-GAGA4 IgM antibody levels are not significantly higher in MS patients, which could potentially explain the poor selectivity of the commercial test.
- Braganza, Chriselle D.,Santoso, Kristiana T.,Dangerfield, Emma M.,La Flamme, Anne C.,Timmer, Mattie S. M.,Stocker, Bridget L.
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p. 28086 - 28093
(2018/08/16)
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- From 1,4-Disaccharide to 1,3-Glycosyl Carbasugar: Synthesis of a Bespoke Inhibitor of Family GH99 Endo-α-mannosidase
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Understanding the enzyme reaction mechanism can lead to the design of enzyme inhibitors. A Claisen rearrangement was used to allow conversion of an α-1,4-disaccharide into an α-1,3-linked glycosyl carbasugar to target the endo-α-mannosidase from the GH99 glycosidase family, which, unusually, is believed to act through a 1,2-anhydrosugar "epoxide" intermediate. Using NMR and X-ray crystallography, it is shown that glucosyl carbasugar α-aziridines can act as reasonably potent endo-α-mannosidase inhibitors, likely by virtue of their shape mimicry and the interactions of the aziridine nitrogen with the conserved catalytic acid/base of the enzyme active site.
- Lu, Dan,Zhu, Sha,Sobala, Lukasz F.,Bernardo-Seisdedos, Ganeko,Millet, Oscar,Zhang, Yongmin,Jiménez-Barbero, Jesus,Davies, Gideon J.,Sollogoub, Matthieu
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supporting information
p. 7488 - 7492
(2019/01/03)
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- Synthesis of 2-deoxy-2,2-difluoro-α-maltosyl fluoride and its X-ray structure in complex with Streptomyces coelicolor GlgEI-V279S
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Streptomyces coelicolor (Sco) GlgEI is a glycoside hydrolase involved in α-glucan biosynthesis and can be used as a model enzyme for structure-based inhibitor design targeting Mycobacterium tuberculosis (Mtb) GlgE. The latter is a genetically validated drug target for the development of anti-Tuberculosis (TB) treatments. Inhibition of Mtb GlgE results in a lethal buildup of the GlgE substrate maltose-1-phosphate (M1P). However, Mtb GlgE is difficult to crystallize and affords lower resolution X-ray structures. Sco GlgEI-V279S on the other hand crystallizes readily, produces high resolution X-ray data, and has active site topology identical to Mtb GlgE. We report the X-ray structure of Sco GlgEI-V279S in complex with 2-deoxy-2,2-difluoro-α-maltosyl fluoride (α-MTF, 5) at 2.3 ? resolution. α-MTF was designed as a non-hydrolysable mimic of M1P to probe the active site of GlgE1 prior to covalent bond formation without disruption of catalytic residues. The α-MTF complex revealed hydrogen bonding between Glu423 and the C1F which provides evidence that Glu423 functions as proton donor during catalysis. Further, hydrogen bonding between Arg392 and the axial C2 difluoromethylene moiety of α-MTF was observed suggesting that the C2 position tolerates substitution with hydrogen bond acceptors. The key step in the synthesis of α-MDF was transformation of peracetylated 2-fluoro-maltal 1 into peracetylated 2,2-difluoro-α-maltosyl fluoride 2 in a single step via the use of Selectfluor.
- Thanna, Sandeep,Lindenberger, Jared J.,Gaitonde, Vishwanath V.,Ronning, Donald R.,Sucheck, Steven J.
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supporting information
p. 7542 - 7550
(2015/07/15)
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- Synthesis of 2-deoxy-2,2-difluoro-α-maltosyl fluoride and its X-ray structure in complex with Streptomyces coelicolor GlgEI-V279S
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Streptomyces coelicolor (Sco) GlgEI is a glycoside hydrolase involved in α-glucan biosynthesis and can be used as a model enzyme for structure-based inhibitor design targeting Mycobacterium tuberculosis (Mtb) GlgE. The latter is a genetically validated drug target for the development of anti-Tuberculosis (TB) treatments. Inhibition of Mtb GlgE results in a lethal buildup of the GlgE substrate maltose-1-phosphate (M1P). However, Mtb GlgE is difficult to crystallize and affords lower resolution X-ray structures. Sco GlgEI-V279S on the other hand crystallizes readily, produces high resolution X-ray data, and has active site topology identical to Mtb GlgE. We report the X-ray structure of Sco GlgEI-V279S in complex with 2-deoxy-2,2-difluoro-α-maltosyl fluoride (α-MTF, 5) at 2.3 ? resolution. α-MTF was designed as a non-hydrolysable mimic of M1P to probe the active site of GlgE1 prior to covalent bond formation without disruption of catalytic residues. The α-MTF complex revealed hydrogen bonding between Glu423 and the C1F which provides evidence that Glu423 functions as proton donor during catalysis. Further, hydrogen bonding between Arg392 and the axial C2 difluoromethylene moiety of α-MTF was observed suggesting that the C2 position tolerates substitution with hydrogen bond acceptors. The key step in the synthesis of α-MDF was transformation of peracetylated 2-fluoro-maltal 1 into peracetylated 2,2-difluoro-α-maltosyl fluoride 2 in a single step via the use of Selectfluor.
- Thanna, Sandeep,Lindenberger, Jared J.,Gaitonde, Vishwanath V.,Ronning, Donald R.,Sucheck, Steven J.
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supporting information
p. 7542 - 7550
(2015/11/27)
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- Photocatalytic synthesis of glycosyl bromides
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Sugar hemiacetals were smoothly transformed into the corresponding glycosyl bromides by treatment with carbon tetrabromide in N,N-dimethylformamide with tris(2,2′-bipyridyl)ruthenium(II) chloride as a catalyst under visible-light irradiation. Protecting groups commonly used in carbohydrate derivatives are unaffected by the mild conditions for bromination. Georg Thieme Verlag KG Stuttgart · New York.
- Yuan, Xiaolong,Cheng, Sen,Shi, Yanbin,Xue, Weihua
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p. 331 - 335
(2014/02/14)
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- Synthesis of uniformly deuterated n-dodecyl-β -d-maltoside (d39 -DDM) for solubilization of membrane proteins in TROSY NMR experiments
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This work reports the first synthesis of uniformly deuterated n-dodecyl-β -D-maltoside (d39-DDM). DDM is a mild non-ionic detergent often used in the extraction and purification of membrane proteins and for solubilizing them in experimental studies of their structure, dynamics and binding of ligands. We required d39-DDM for solubilizing large α-helical membrane proteins in samples for [15N-1H]TROSY (transverse relaxation-optimized spectroscopy) NMR experiments to achieve the highest sensitivity and best resolved spectra possible. Our synthesis of d39-DDM used d7-D-glucose and d25-n-dodecanol to introduce deuterium labelling into both the maltoside and dodecyl moieties, respectively. Two glucose molecules, one converted to a glycosyl acceptor with a free C4 hydroxyl group and one converted to a glycosyl donor substituted at C1 with a bromine in the α-configuration, were coupled together with an α(1 → 4) glycosidic bond to give maltose, which was then coupled with n-dodecanol by its substitution of a C1 bromine in the α-configuration to give DDM. 1H NMR spectra were used to confirm a high level of deuteration in the synthesized d39-DDM and to demonstrate its use in eliminating interfering signals from TROSY NMR spectra of a 52-kDa sugar transport protein solubilized in DDM.
- Hiruma-Shimizu, Kazumi,Kalverda, Arnout P.,Henderson, Peter J. F.,Homans, Steve W.,Patching, Simon G.
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p. 737 - 743
(2015/02/19)
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- Synthesis of quercetin glycosides and their melanogenesis stimulatory activity in B16 melanoma cells
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4′-O-β-d-Glucopyranosyl-quercetin-3-O-β-d-glucopyranosyl- (1→4)-β-d-glucopyra-noside (3) was isolated from Helminthostachys zeylanica root extract as a melanogenesis acceleration compound and was synthesized using rutin as the starting material Related compounds were also synthesized to understand the structure-activity relationships in melanin biosynthesis Melanogenesis activities of the glycosides were determined by measuring intracellular melanin content in B16 melanoma cells Among the synthesized quercetin glycosides, quercetin-3-O-β-d-glucopyranoside (1), quercetin-3-O-β-d-glucopyranosyl-(1→4)-β-d-glucopyranoside (2), and 3 showed more potent intracellular melanogenesis acceleration activities than theophyline used as positive control in a dose-dependent manner with no cytotoxic effect
- Yamauchi, Kosei,Mitsunaga, Tohru,Batubara, Irmanida
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p. 937 - 944
(2014/02/14)
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- Appel-reagent-mediated transformation of glycosyl hemiacetal derivatives into thioglycosides and glycosyl thiols
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A series of glycosyl hemiacetal derivatives have been transformed into thioglycosides and glycosyl thiols in a one-pot two-step reaction sequence mediated by Appel reagent (carbon tetrabromide and triphenylphosphine). 1,2-trans-Thioglycosides and β-glycosyl thiol derivatives were stereoselectively formed by the reaction of the in situ generated glycosyl bromides with thiols and sodium carbonotrithioate. The reaction conditions are reasonably simple and yields were very good.
- Ghosh, Tamashree,Santra, Abhishek,Misra, Anup Kumar
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p. 974 - 982
(2013/07/19)
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- Synthesis of fluorinated maltose derivatives for monitoring protein interaction by 19F NMR
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A novel reporter system, which is applicable to the 19F NMR investigation of protein interactions, is presented. This approach uses 2-F-labeled maltose as a spy ligand to indirectly probe protein-ligand or protein-protein interactions of proteins fused or tagged to the maltose-binding protein (MBP). The key feature is the simultaneous NMR observation of both 19F NMR signals of gluco/ manno-type-2-F-maltose-isomers; one isomer (α-gluco-type) binds to MBP and senses the protein interaction, and the nonbinding isomers (β-gluco- and/or α/β-manno-type) are utilized as internal references. Moreover, this reporter system was used for relative affinity studies of fluorinated and nonfluorinated carbohydrates to the maltose-binding protein, which were found to be in perfect agreement with published X-ray data. The results of the NMR competition experiments together with the established correlation between 19F chemical shift data and molecular interaction patterns, suggest valuable applications for studies of protein-ligand interaction interfaces.
- Braitsch, Michaela,Kaehlig, Hanspeter,Kontaxis, Georg,Fischer, Michael,Kawada, Toshinari,Konrat, Robert,Schmid, Walther
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supporting information; experimental part
p. 448 - 455
(2012/06/30)
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- Synthetic studies of bi-fluorescence-labeled maltooligosaccharides as substrates for α-amylase on the basis of fluorescence resonance energy transfer (FRET)
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A series of bi-fluorescence-labeled maltooligosaccharides that lead to fluorescence resonance energy transfer (FRET) was systematically synthesized. Effective FRETs were observed with all of the synthesized probes. Digestion of probes having tetra-, quintet-, hexa- or hepta-saccharidic chain lengths with human saliva α-amylase resulted in disappearance of FRET when an excitation wavelength of at 290 nm was used followed by detection at ca. 520 nm due to emission from the dansyl moiety. However, continuous FRET was observed when probes having di- or trisaccharidic chain lengths were used as substrates. In addition to the substrate characteristics based on saccharidic chain length, the reaction rates of digestion for the substrates by amylase were different and also depended on their saccharidic chain length.
- Oka, Hiroyuki,Koyama, Tetsuo,Hatano, Ken,Matsuoka, Koji
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experimental part
p. 435 - 445
(2012/03/10)
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- Sweet chiral porphyrins as singlet oxygen sensitizers for asymmetric Type II photooxygenation
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Carbohydrate-decorated meso-tetraarylporphyrins P-G and P-C were synthesized via Lewis-acid catalyzed condensation of acetylated carbohydrate-substituted benzaldehydes and pyrrole. Their efficiency of singlet oxygen production was compared with the corresponding non-substituted porphyrin. The oxidation of the spin trap molecule TEMP (2,2,6,6-tetramethyl-4-piperidone) by singlet oxygen to TEMPO was measured by ESR spectroscopy, showing higher reaction rates for the sugar porphyrins. These results were corroborate by laser flash photolysis measurements that resulted in higher triplet lifetimes of glucosyl- and cellobiosyl porphyrins in comparison with tetrakis(4- hydroxyphenyl)porphyrin. Low ee was detected in the photooxygenation of ethyl tiglate. The Royal Society of Chemistry and Owner Societies.
- Griesbeck, Axel G.,Miranda, Miguel A.,Uhlig, Johannes
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scheme or table
p. 1431 - 1435
(2012/06/30)
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- Comparative study of microwave induced and conventional synthesis of acetylated sugar isothiocyanates and related thiocarbamides
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The synthesis of several acetylated sugar isothiocyanates have been carried out under microwave irradiation in excellent yields of products by using related bromides and lead thiocyanate in sodium dried xylene. Several acetylated sugar thiocarbamides have been synthesized by the interaction of respective acetylated sugar isothiocyanates with appropriate aryl amines under microwave irradiation. Copyright E-Journal of Chemistry 2004-2011.
- Yadgire, Atul V.,Korpe, Gajanan V.,Deshmukh, Shirish P.
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p. 1614 - 1619
(2012/05/05)
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- Dynamic glycovesicle systems for amplified QCM detection of carbohydrate-lectin multivalent biorecognition
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We describe multivalent biorecognition of adsorbed lectin layers by biomimetic sensing nanoplatforms based on dynamic glycovesicles in a continuous flow QCM setup. The Royal Society of Chemistry.
- Mahon, Eugene,Aastrup, Teodor,Barboiu, Mihail
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supporting information; experimental part
p. 2441 - 2443
(2010/08/05)
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- Preparation of aminoethyl glycosides for glycoconjugation
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The synthesis of a number of aminoethyl glycosides of cell-surface carbohydrates, which are important intermediates for glycoarray synthesis, is described. A set of protocols was developed which provide these intermediates, in a short number of steps, from commercially available starting materials.
- Sardzik, Robert,Noble, Gavin T.,Weissenborn, Martin J.,Martin, Andrew,Webb, Simon J.,Flitsch, Sabine L.
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supporting information; experimental part
p. 699 - 703
(2011/01/03)
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- NOVEL SULFATED OLIGOSACCHARIDE DERIVATIVES
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The invention relates to novel compounds that have utility as inhibitors of heparan sulfate-binding proteins; compositions comprising the compounds, and use of the compounds and compositions thereof for the antiangiogenic, antimetastatic, anti-inflammatory, antimicrobial, anticoagulant and/or antithrombotic treatment of a mammalian subject.
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Page/Page column 56
(2009/05/28)
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- Probing the lactose·GM3 carbohydrate - Carbohydrate interaction with glycodendrimers
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(Figure Presented) Multivalent glycoconjugates were prepared using generation-4 PAMAM dendrimers, and their interaction with Langmuir monolayers containing GM3 was investigated. Excessive carbohydrate valency adversely affects the carbohydrate-carbohydrate interaction. The GM3 monolayer selectively interacts with lactose-functionalized dendrimers in the presence of calcium ions.
- Seah, Nicole,Santacroce, Paul V.,Basu, Amit
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supporting information; experimental part
p. 559 - 562
(2009/07/30)
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- Synthesis of urea tethered glycosylated amino acids and glycopeptides mediated by DPPA employing Nα-Fmoc-Asp/Glu-5-oxazolidinones
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The utility of diphenyl phosphoryi azide (DPPA) as azido transfer reagent for the insertion of urea moiety between β/γ carboxyl group of N a-Fmoc-Asp/Glu-5-oxazolidinones and glycosyl amine has been demonstrated. Utility of this protocol for the synthesis of urea-linked neoglycopeptides has also been explored. The compounds are characterised by '1H NMR, l3C NMR and mass spectroscopy.
- Nagendra,Hemantha,Sureshbabu, Vommina V.
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scheme or table
p. 397 - 407
(2009/12/26)
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- Facile synthesis of 2-0-lodoacetyl protected glycosyl iodides: Useful precursors of 1→2-linked 1,2-trans-glycosides
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(Chemical Equation Presented) The preparation and utilization of novel iodide glycosyl donors, 2-0-iodoacetyl-glycopyranosyl iodides, is described. The mechanism for the reaction of iodine with carbohydrate cyclic ketene acetal was investigated through lo
- Ko, Yoon-Joo,Shim, Seung-Bo,Shin, Jung-Hyu
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body text
p. 609 - 612
(2009/07/25)
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- Large-scale synthesis of per-O-acetylated saccharides and their sequential transformation to glycosyl bromides and thioglycosides
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This work describes a large-scale synthesis of per- O -acetylated mono- and disaccharides using a stoichiometric amount of acetic anhydride in the presence of LiClO 4 under solvent-free conditions. The peracetylated saccharides underwent subsequent anomeric bromination and thioglycosidation in one-pot to yield synthetically valuable building blocks. Copyright Taylor & Francis Group, LLC.
- Lin, Chan-Ching,Huang, Li-Cheng,Liang, Pi-Hui,Liu, Ching-Yang,Lin, Chun-Cheng
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p. 303 - 313
(2007/10/03)
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- Mild one-pot preparation of glycosyl bromides
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Mild one-pot protocols for the preparation of glycosyl bromides and alkyl bromides via in situ generation of HBr is reported here.
- Hunsen, Mo,Long, David A.,D'Ardenne, Christopher R.,Smith, Amanda L.
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p. 2670 - 2674
(2007/10/03)
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- Synthetic long-chain alkyl maltosides and alkyl sucrose esters as enhancers of nasal insulin absorption
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A series of new glycosides with extended alkyl side-chains (C13-16) linked to maltose or sucrose were synthesized and tested for their efficacy in enhancing nasal insulin absorption in anesthetized rats. The new reagents were compared to previously tested alkylglycosides with shorter alkyl side chains (C8-12). Dose-response studies revealed that within the family of alkylmaltoside derivatives, (C8-16), maximal increases in insulin absorption took place when tetradecylmaltoside (C14) was added to the formulation. Pentadecylmaltoside (C15) and hexadecylmaltoside (C16) were less potent at increasing insulin absorption, although both reagents achieved maximal effects when used at higher concentrations. Within the family of alkanoylsucrose derivatives, tride-canoylsucrose (C13) and tetradecanoylsucrose (C14) were most potent at increasing insulin absorption. Cross-comparisons between alkylmaltoses and alkanoylsucroses showed that the alkyl chain length had a greater impact than the glycoside moiety in determining the potency of a potential insulin-absorption enhancing agent. When tetradecylmaltoside was applied to the nasal mucosa 15 min before insulin was applied, the enhanced insulin absorption was still observed.
- Pillion, Dennis J.,Ahsan, Fakhrul,Arnold, John J.,Balusubramanian, Balu M.,Piraner, Olga,Meezan, Elias
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p. 1456 - 1462
(2007/10/03)
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- Mild synthesis of disaccharidic 2,3-enopyranosyl cyanides and 2-C-2-deoxy pyranosyl cyanides with Hg(CN)2/HgBr2/TMSCN
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Lewis acid-catalyzed dimerization of mono- and disaccharidic per-O-acetylated glycals gave di- and tetrasaccharidic O-acetylated C-glycosides, respectively. 2,3-Enopyranosyl cyanides were obtained from per-O-acetylated glycals by a new, mild anomeric SN′-acetoxy displacement with Hg(CN)2/HgBr2/TMSCN. Per-O-acetylated 2-C-2-deoxy-pyranoses were converted into pyranosyl cyanides by the same reagent. An unprecedented acetic acid elimination from dimers with D-galacto- and L-fuco-configurations accompanied the SN-displacement under those conditions. A new set of 1H NMR coupling constants for 2,3-enopyranosyl systems was used for configurational assignment of complicated tetrasaccharide mimics.
- Franz, Andreas H.,Wei, YiQiu,Samoshin, Vyacheslav V.,Gross, Paul H.
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p. 7662 - 7669
(2007/10/03)
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- Carbohydrate-carbohydrate interactions in water with glycophanes as model systems
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The synthesis and conformational properties of glycophanes 2 and 3 (cyclodextrin-cyclophane hybrid receptors containing two maltose units linked by (4-hydroxymethyl) benzoic acid spacer) are described. The binding properties in water of these receptors with a series of 4-nitrophenyl glycosides with α- and β-configurations at the anomeric center have been studied using 1H NMR spectroscopy and molecular mechanics calculations. A comparison of these properties with those of glycophane 1 (an α,α-trehalose containing glycophane) and α-cyclodextrin (αCD) using the same glycosides shows the existence of a stabilizing contribution to the free energy of binding in the case of of glycophanes but not in the case of the αCD system. This contribution is due to carbohydrate-carbohydrate interactions between both host and guest lipophilic sugar surfaces. Glycophanes 1, 2, and 3 show similar α/β selectivity on binding the ligands, despite the great flexibility of 3 related to 1 and 2. Parallels are drawn between the thermodynamic behavior of these model systems and that proposed for sugar- protein interactions.
- Morales, Juan Carlos,Zurita, Dacil,Penades, Soledad
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p. 9212 - 9222
(2007/10/03)
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- A convenient synthesis of peracetylated glycosyl halides using bismuth(III) halides as catalysts
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A new halogenation procedure for peracetylated glycopyranosides is reported, using bismuth(III) halides and halogenosilanes under very mild conditions.
- Montero, Jean-Louis,Winum, Jean-Yves,Leydet, Alain,Kamal, Mehrnaz,Pavia, Andre A.,Roque, Jean-Pierre
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p. 175 - 180
(2007/10/03)
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- Two interconverting glycophanes from maltose
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Two new glycophanes, 1 and 3, that interconvert through transesterification in water at room temperature are presented. The synthesis, properties of interconvertion and preliminary binding and conformational studies of these macrocycles are also described.
- Morales, Juan Carlos,Penades, Soledad
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p. 5011 - 5014
(2007/10/03)
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- A convenient, highly efficient one-pot preparation of peracetylated glycals from reducing sugars
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A convenient, highly efficient, one-pot, three-step procedure has been developed for the synthesis of peracetylated glycal derivatives from various reducing sugars including D-glucose, D-galactose, L-rhamnose, L-arabinose, D-maltose, D-lactose, and maltotriose. This procedure involves peracetylation of the reducing sugars with acetic anhydride and HBr/acetic acid followed by the transformation of the anomeric acetates to the corresponding bromides with additional HBr/acetic acid and finally reductive elimination of the 1-bromo and 2-acetoxy groups with Zn/CuSC4·5H2O in acetic acid/water containing sodium acetate. The overall yields of purified peracetylated glycals from the corresponding sugars range from 50 - 98%.
- Shull, Brian K.,Wu, Zhijun,Koreeda, Masato
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p. 955 - 964
(2007/10/03)
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- Inclusion and solubilization properties of 6-S-glycosyl-6-thio derivatives of β-cyclodextrin
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The synthesis and physico-chemical properties of branched β-cyclodextrins substituted by one or seven thioglycoside units at the primary hydroxy side are described.The solubilities in water of these compounds are strongly increased compared with the paren
- Laine, Valerie,Coste-Sarguet, Annie,Gadelle, Andree,Defaye, Jacques,Perly, Bruno,Djedaini-Pilard, Florence
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p. 1479 - 1488
(2007/10/02)
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- Glycoconjugated Porphyrins. 2. Synthesis of Sterically Constrained Polyglycosylated Compounds Derived from Tetraphenylporphyrins
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A variety of glycoconjugated porphyrins has been synthesized by Lindsey's method from pyrrole and o-acetylglycosylated benzaldehyde precursors.Deprotection of glucose and maltose moieties allows the production of derivatives which had a good solubillity i
- Maillard, Philippe,Guerquin-Kern, Jean-Luc,Huel, Christiane,Momenteau, Michel
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p. 2774 - 2780
(2007/10/02)
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- Thermal Rearrangement of Alkyl O-Vinylcarbohydroximates to 2-Alkyloxazoles
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Alkyl O-vinylcarbohydroximates, lactoxime O-vinyl ethers, and sugar lactoxime O-vinyl ethers undergo a novel thermal rearrangement to afford the corresponding 2-alkyloxazoles, 2-(ω-hydroxyalkyl)oxazoles, and oxazoles bearing a sugar moiety, respectively.This rearrangement can also occur under photochemical conditions.
- Yokoyama, Masataka,Irie, Masakazu,Sujino, Keiko,Kagemoto, Tsukusi,Togo, Hideo,Funabashi, Masuo
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p. 2127 - 2134
(2007/10/02)
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- Convenient preparation of glycosyl bromides
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Glycosyl bromides were prepared in very good yields by bromination of the corresponding anomeric hydroxyl group using a l:l mixture of triphenyl phosphite and bromine as reagent.
- Mani,Kanakamma
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p. 2175 - 2182
(2007/10/02)
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- Stereoselective Synthesis of Long-chain 1-O-(β-D-Maltosyl)-3-O-alkyl-sn-glycerols (Alkyl Glyceryl Ether Lysoglycolipids)
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The synthesis of long-chain 2-O-benzyl-3-O-alkyl-sn-glycerols 5 was improved, making these compounds easily accessible for glycosylation experiments.Glycosylation with α-acetobromomaltose following a modified Koenings-Knorr procedure after removal of the protective groups yielded the title compound 9 in good yields.These compounds represent examples of alkyl glyceryl ether lysoglycolipids.Some properties of these amphiphilic compounds with a nonionic carbohydrate head-group differ not much (critical micell concentration, hemolytic activity), other properties differ very much (antitumor efficiency) from the properties of the analogous compounds with a zwitterionic phosphorylcholine head-group.
- Prinz, Harald,Six, Lambert,Ruess, Klaus-Peter,Lieflaender, Manfred
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p. 217 - 225
(2007/10/02)
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- STEREOSELECTIVITY IN THE DEHYDRATIVE GLYCOSYLATION WITH HEPTA-O-BENZYL-GLUCOBIOSES
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Dehydrative glycosylation of benzyl 2,3,4-tri-O-benzyl α-D-glucopyranoside with hepta-O-benzyl-kojibiose, -sophorose, -nigerose, -laminaribiose, -maltose, -cellobiose, -isomaltose, and -gentiobiose gave 16 linear trisaccharide derivatives.The reaction of α(1->2)-, β(1->3)-, α(1->4)-, and β(1->6)-linked biose derivatives shows the α-selectivity, while the reaction of the others does the β-selectivity.
- Morishima, Naohiko,Koto, Shinkiti,Irisawa, Terumi,Hashimoto, Yosuke,Yamazaki, Masayo,et al.
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p. 1383 - 1384
(2007/10/02)
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- Synthesis of alpha- and beta-glycosides containing spin labels, as probes for studies of carbohydrate-protein interaction.
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Nitroxide spin-labeled alpha-D-glycopyranosides were synthesized in good yield and in a highly stereoselective manner by reaction of per-O-benzyl-alpha-D-glycopyranosyl bromides with 2,2,6,6-tetramethyl-4-piperidinol under the bromide ion-catalyzed conditions devised by Lemieux et al. After hydrogenolysis, the deblocked intermediates were oxidized to give the desired, spin-labeled alpha-D-glycopyranosides. Nitroxide spin-labeled beta-D-glycopyranosides, as well as a beta-maltoside, were synthesized by standard methods. The synthesis is also described of 2-amino-2-deoxy-D-glucose and -D-galactose derivatives having a spin label at C-2, and of the spin-labeled compound 1-[4-(beta-D-galactopyranosyloxy)phenyl]-3-(2,2,6,6-tetramethylpiperidin-1-oxyl -4-yl)-2-thiourea.
- Plessas,Goldstein
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p. 211 - 220
(2007/10/02)
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