- Glycosylation in room temperature ionic liquid using unprotected and unactivated donors
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Glycosylation in room temperature ionic liquid is demonstrated using unprotected and unactivated donors. Modest yields of simple benzyl glycosides and disaccharides of glucose, mannose and N-acetylgalactosamine were obtained in 1-ethyl-3-methylimidazolium benzoate with Amberlite IR-120 (H+) resin or p-toluenesulfonic acid as promoters.
- Park, Tae-Joon,Weiwer, Michel,Yuan, Xuejun,Baytas, Sultan N.,Munoz, Eva M.,Murugesan, Saravanababu,Linhardt, Robert J.
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Read Online
- Anomeric alkylations and acylations of unprotected mono- and disaccharides mediated by pyridoneimine in aqueous solutions
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A site-specific deprotonation followed by alkylations and acylations of sugar hemiacetals to the corresponding alkyl glycosides and acylated sugars in aqueous solutions is disclosed herein. Pyridoneimine as a new base is developed to mediate the deprotonation of readily available sugar hemiacetals and further reactions with alkylation and acylation agents.
- Dey, Kalyan,Jayaraman, Narayanaswamy
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supporting information
p. 2224 - 2227
(2022/02/17)
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- Rhamnogalacturonan II: Chemical Synthesis of a Substructure Including α-2,3-Linked Kdo**
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The synthesis of a fully deprotected Kdo-containing rhamnogalacturonan II pentasaccharide is described. The strategy relies on the preparation of a suitably protected homogalacturonan tetrasaccharide backbone, through a post-glycosylation oxidation approach, and its stereoselective glycosylation with a Kdo fluoride donor.
- Mancuso, Enzo,Romanò, Cecilia,Trattnig, Nino,Gritsch, Philipp,Kosma, Paul,Clausen, Mads H.
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p. 7099 - 7102
(2021/04/19)
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- Multi-gram scale synthesis of a bleomycin (BLM) carbohydrate moiety: exploring the antitumor beneficial effect of BLM disaccharide attached to 10-hydroxycamptothecine (10-HCPT)
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The “tumor-seeking” role of bleomycin (BLM) disaccharide has been demonstrated to serve as a promising tool for cancer diagnosis and a potential ligand for targeted therapy. However, these practical applications are often hampered by the lack of BLM disaccharide. Herein, an efficient multi-gram synthesis of peracetylated BLM disaccharide 20 is achieved by a TMSOTF-mediated glycosidation coupling manner in 43.6% overall yield in terms of benzyl galactoside. The critical innovation of the synthetic strategy is that inexpensive benzyl galactoside was first adopted to prepare an l-gulose subunit 3 as a glycosyl acceptor, with a much shorter route in 73.0% yield, and a 3-O-carbamoyl-mannose donor 4 was achieved in 47.2% yield by lowering the amount of dibutyltin oxide, and merging aminolysis and selective deacetylation into a one-pot reaction. Next, the incorporation of BLM disaccharide into 10-hydroxycamptothecin (10-HCPT), a non-specific model compound, to form conjugate 1 could significantly improve the antitumor activity and display obvious selectivity toward cancerous and normal cells in comparison with 10-HCPT. Moreover, BLM disaccharide itself was non-cytotoxic, clearly indicating the importance and potential of BLM disaccharide in solving the targeted antitumor therapy of cytotoxic drugs.
- Li, MaoLin,Huang, Weiping,Jiang, Zhilin,Shi, Yonghui,Yuan, Sisi,Fu, Kaishuo,Chen, YongJun,Zhou, Li,Zhou, Wen
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p. 6010 - 6020
(2019/04/17)
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- INHIBITORS OF HEXOKINASE AND METHODS OF USE THEREOF
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Provided herein are substituted substituted heterocycles useful as inhibitors of the HKII enzyme. The invention further provides pharmaceutical compositions of the compounds of the invention. The invention further provides medical uses of substituted heterocycles, for example, as antitumor agents.
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Page/Page column 77; 78
(2018/09/25)
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- Preparation methods of 2-hydroxygulose receptor derivative, bleomycin disaccharide and precursor of bleomycin disaccharide
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The invention discloses a preparation method of a 2-hydroxygulose receptor derivative. The method comprises the following steps: carrying out a series of reactions of ylidene protection on benzyl-beta-galactoside, 3-position configuration inversion, deacetylation, and selective acetylation. Meanwhile, the invention also discloses a method for preparing bleomycin disaccharide and a precursor of bleomycin disaccharide by using the 2-hydroxygulose receptor derivative prepared by the method as a receptor. According to the invention, through the adoption of the preparation method of the 2-hydroxygulose receptor derivative, the problems that sources of natural L-gulose are rare, cost is too high, and industrialization is not facilitated and the like are solved; meanwhile, the problems that the bleomycin disaccharide and the precursor of the bleomycin disaccharide are low in yield, reaction operability and repeatability are poor, industrialization is not facilitated and the like are solved. The preparation methods have the advantages that raw materials are cheap and easily available, the yield is high, the operability is high, conditions can be easily controlled, industrial amplificationcan be realized, efficiency is high, cost is low, and the like.
- -
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Paragraph 0050-0057; 0076-0080; 0090-0094
(2019/01/08)
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- Glycosylated Platinum(IV) Complexes as Substrates for Glucose Transporters (GLUTs) and Organic Cation Transporters (OCTs) Exhibited Cancer Targeting and Human Serum Albumin Binding Properties for Drug Delivery
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Glycosylated platinum(IV) complexes were synthesized as substrates for GLUTs and OCTs for the first time, and the cytotoxicity and detailed mechanism were determined in vitro and in vivo. Galactoside Pt(IV), glucoside Pt(IV), and mannoside Pt(IV) were highly cytotoxic and showed specific cancer-targeting properties in vitro and in vivo. Glycosylated platinum(IV) complexes 5, 6, 7, and 8 (IC50 0.24-3.97 μM) had better antitumor activity of nearly 166-fold higher than the positive controls cisplatin (1a), oxaliplatin (3a), and satraplatin (5a). The presence of a hexadecanoic chain allowed binding with human serum albumin (HSA) for drug delivery, which not only enhanced the stability of the inert platinum(IV) prodrugs but also decreased their reduction by reductants present in human whole blood. Their preferential accumulation in cancer cells compared to noncancerous cells (293T and 3T3 cells) suggested that they were potentially safe for clinical therapeutic use.
- Ma, Jing,Wang, Qingpeng,Huang, Zhonglv,Yang, Xiande,Nie, Quandeng,Hao, Wenpei,Wang, Peng George,Wang, Xin
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supporting information
p. 5736 - 5748
(2017/07/22)
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- Direct glycosylation of bioactive small molecules with glycosyl iodide and strained olefin as acid scavenger
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A new strategy for diversity-oriented direct glycosylation of bioactive small molecules was developed. This reaction features (-)-β-pinene as acid scavenger and work with glycosyl iodides under mild conditions. With the aid of RP-HPLC and chiral SFC separation techniques, the new direct glycosylation proved effective at gram scale on bioactive small molecules including AZD6244, podophyllotoxin, paclitaxel, and docetaxel. Interesting glycoside derivatives were efficiently created with good yields and 1,2-cis selectivity.
- Gu, Xiangying,Chen, Lin,Wang, Xin,Liu, Xiao,You, Qidong,Xi, Wenwei,Gao, Li,Chen, Guohua,Chen, Yue-Lei,Xiong, Bing,Shen, Jingkang
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p. 1100 - 1110
(2014/03/21)
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- Chemoenzymatic synthesis of ADP-d-glycero-β-d-manno-heptose and study of the substrate specificity of HldE
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An efficient one-pot three enzymes strategy for chemoenzymatic synthesis of ADP-d-glycero-β-d-manno-heptose (ADP-d, d-heptose) was reported using chemically synthesized d, d-heptose-7-phosphate and the ADP-d, d-heptose biosynthetic enzymes HldE and GmhB M
- Li, Tiehai,Wen, Liuqing,Williams, Adriel,Wu, Baolin,Li, Lei,Qu, Jingyao,Meisner, Jeffrey,Xiao, Zhongying,Fang, Junqiang,Wang, Peng George
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p. 1139 - 1147
(2014/02/14)
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- 1,2-cis Alkyl glycosides: Straightforward glycosylation from unprotected 1-thioglycosyl donors
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A 1,2-cis-alkyl glycosidation protocol that makes use of unprotected phenyl 1-thioglycosyl donors is reported. Glycosylation of various functionalized alcohols was accomplished in moderate to high yield and selectivity to give the 1,2-cis-glycosides. In order to quickly develop optimum glycosylation conditions, an FIA (flow injection analysis)-ESI-TOF-MS method was developed that enabled rapid and quantitative evaluation of yield on small scale. This methodology, coupled with NMR spectroscopy, allowed for rapid evaluation of the overall reactions.
- Meng, Bo,Zhu, Zhenqian,Baker, David C.
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p. 5182 - 5191
(2014/07/08)
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- Synthesis of benzyl β-d-galactopyranoside by transgalactosylation using a β-galactosidase produced by the over expression of the Kluyveromyces lactis LAC4 gene in Arxula adeninivorans
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The LAC4 gene of Kluyveromyces lactis encoding for β-galactosidase was overexpressed in the yeast Arxula adeninivorans to produce the enzyme, which can be used for the synthesis of β-d-galactosides. These compounds play a major role as precursors for the
- Rauter, Marion,Schwarz, Maria,Becker, Karin,Baronian, Keith,Bode, Ruediger,Kunze, Gotthard,Vorbrodt, H.-Matthias
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p. 319 - 327
(2013/11/19)
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- Chondroitin-4-O-sulfatase from Bacteroides thetaiotaomicron: Exploration of the substrate specificity
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Bacterial sulfatases can be good tools to increase the molecular diversity of glycosaminoglycan synthetic fragments. A chondroitin 4-O-sulfatase from the human commensal bacterium Bacteroides thetaiotaomicron has recently been identified and expressed. In order to use this enzyme for synthetic purposes, the minimal structure required for its activity has been determined. For that, four 4-O-sulfated monosaccharides and one 4-O-sulfated disaccharide have been synthesized and used as substrates with the sulfatase. The minimum structure was shown to be a disaccharide but in contrast to the natural substrate, which must have a 4,5-insaturation, the enzyme accepts as substrate, a disaccharide with a saturated glucuronic acid at the non-reducing end and even a glucopyranosyl moiety without the carboxylic acid functionality.
- Malleron, Annie,Benjdia, Alhosna,Berteau, Olivier,Le Narvor, Christine
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scheme or table
p. 96 - 99
(2012/07/01)
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- COMPOUNDS AND METHODS FOR TREATING BACTERIAL INFECTIONS
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The present invention encompasses compounds and methods for treating urinary tract infections.
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Page/Page column 69-70
(2011/05/06)
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- An efficient synthesis of selectively functionalized D-rhamnose derivatives
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D-Rhamnose is an important component of bacterial lipopolysaccharides. This paper describes a short and highly efficient synthesis of D-rhamnose from D-mannose. The synthesis of selectively C-4 modified d-rhamnosides and 6-deoxy-D-talosides as potential building blocks for complex oligosaccharide synthesis is also discussed.
- Zunk, Matthew,Kiefel, Milton J.
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supporting information; experimental part
p. 1296 - 1299
(2011/03/22)
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- Synthesis, biological activity of salidroside and its analogues
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Salidroside is a phenylpropanoid glycoside isolated from Rhodiola rosea L., a traditional Chinese medicinal plant, and has displayed a broad spectrum of pharmacological properties. In this paper, about 18 novel salidroside analogues were prepared through Koenigs-Knorr method, the effects of these compounds over PC12 was assessed with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. The novel compounds differ in the substituents attached to the benzene ring or in the glycosyl donor. According to the data, compounds (3,5-dimethoxyphenyl)methyl β-D-glucopyranoside and (3,5-dimethoxyphenyl) methyl β-D-galactopyranoside with methoxy group at 3 and 5-positions of the benzene ring were the most viability at concentration of 300 μmol/l and 60 μmol/l, respectively.
- Guo, Yibing,Zhao, Yahong,Zheng, Cheng,Meng, Ying,Yang, Yumin
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experimental part
p. 1627 - 1629
(2011/02/24)
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- FimH antagonists for the oral treatment of urinary tract infections: From design and synthesis to in vitro and in vivo evaluation
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Urinary tract infection (UTI) by uropathogenic Escherichia coli (UPEC) is one of the most common infections, particularly affecting women. The interaction of FimH, a lectin located at the tip of bacterial pili, with high mannose structures is critical for the ability of UPEC to colonize and invade the bladder epithelium. We describe the synthesis and the in vitro/in vivo evaluation of α-d-mannosides with the ability to block the bacteria/host cell interaction. According to the pharmacokinetic properties, a prodrug approach for their evaluation in the UTI mouse model was explored. As a result, an orally available, low molecular weight FimH antagonist was identified with the potential to reduce the colony forming units (CFU) in the urine by 2 orders of magnitude and in the bladder by 4 orders of magnitude. With FimH antagonist 16b, the great potential for the effective treatment of urinary tract infections with a new class of orally available antiinfectives could be demonstrated.
- Klein, Tobias,Abgottspon, Daniela,Wittwer, Matthias,Rabbani, Said,Herold, Janno,Jiang, Xiaohua,Kleeb, Simon,Lüthi, Christine,Scharenberg, Meike,Bezen?on, Jacqueline,Gubler, Erich,Pang, Lijuan,Smiesko, Martin,Cutting, Brian,Schwardt, Oliver,Ernst, Beat
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supporting information; experimental part
p. 8627 - 8641
(2011/02/28)
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- Structure-based drug design and optimization of mannoside bacterial fimH antagonists
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FimH-mediated cellular adhesion to mannosylated proteins is critical in the ability of uropathogenic E. coli (UPEC) to colonize and invade the bladder epithelium during urinary tract infection. We describe the discovery and optimization of potent small-molecule FimH bacterial adhesion antagonists based on α-d-mannose 1-position anomeric glycosides using X-ray structure-guided drug design. Optimized biarylmannosides display low nanomolar binding affinity for FimH in a fluorescence polarization assay and submicromolar cellular activity in a hemagglutination (HA) functional cell assay of bacterial adhesion. X-ray crystallography demonstrates that the biphenyl moiety makes several key interactions with the outer surface of FimH including π-π interactions with Tyr-48 and an H-bonding electrostatic interaction with the Arg-98/Glu-50 salt bridge. Dimeric analogues linked through the biaryl ring show an impressive 8-fold increase in potency relative to monomeric matched pairs and represent the most potent FimH antagonists identified to date. The FimH antagonists described herein hold great potential for development as novel therapeutics for the effective treatment of urinary tract infections.
- Han, Zhenfu,Pinkner, Jerome S.,Ford, Bradley,Obermann, Robert,Nolan, William,Wildman, Scott A.,Hobbs, Doug,Ellenberger, Tom,Cusumano, Corinne K.,Hultgren, Scott J.,Janetka, James W.
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experimental part
p. 4779 - 4792
(2010/10/03)
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- A nonself sugar mimic of the HIV glycan shield shows enhanced antigenicity
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Antibody 2G12 uniquely neutralizes a broad range of HIV-1 isolates by binding the high-mannose glycans on the HIV-1 surface glycoprotein, gp120. Antigens that resemble these natural epitopes of 2G12 would be highly desirable components for an HIV-1 vaccine. However, host-produced (self)-carbohydrate motifs have been unsuccessful so far at eliciting 2G12-like antibodies that cross-react with gp120. Based on the surprising observation that 2G12 binds nonproteinaceous monosaccharide D-fructose with higher affinity than D-mannose, we show here that a designed set of nonself, synthetic monosaccharides are potent antigens. When introduced to the terminus of the D1 arm of protein glycans recognized by 2G12, their antigenicity is significantly enhanced. Logical variation of these unnatural sugars pinpointed key modifications, and the molecular basis of this increased antigenicity was elucidated using high-resolution crystallographic analyses. Virus-like particle protein conjugates containing such nonself glycans are bound more tightly by 2G12. As immunogens they elicit higher titers of antibodies than those immunogenic conjugates containing the self D1 glycan motif. These antibodies generated from nonself immunogens also cross-react with this self motif, which is found in the glycan shield, when it is presented in a range of different conjugates and glycans. However, these antibodies did not bind this glycan motif when present on gp120.
- Doores, Katie J.,Fulton, Zara,Hong, Vu,Patel, Mitul K.,Scanlan, Christopher N.,Wormald, Mark R.,Finn,Burton, Dennis R.,Wilson, Ian A.,Davis, Benjamin G.
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scheme or table
p. 17107 - 17112
(2011/02/25)
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- Glycosylation using unprotected alkynyl donors
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(Chemical Equation Presented) Gold(III) activation of unprotected propargyl glycosyl donors has been shown to be effective for the synthesis of saccharides. Terminal propargyl glycosides of glucose, galactose, and mannose required heating at reflux in ace
- Mamidyala, Sreeman K.,Finn
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experimental part
p. 8417 - 8420
(2010/01/16)
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- Synthesis of |β-(1→2)-linked oligomannosides
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β-(1→2)-Linked oligomannosides constitute an important class of carbohydrate structures located on the cell surface of several Candida species, including C. albicans. As a result of the immunostimulating properties of such compounds, the upscaling of their synthesis is relevant. In this paper, a highly stereoselective synthesis of |β-(1→2)-linked oligomannosides was performed by further development of and modifications to the methodologies described earlier in the literature. In addition to the synthesis of fully deprotected β-(1→2)-linked mannobiose and mannotriose, some preliminary modifications to the oligosaccharide core, resulting in close analogues with biological potential, are presented. The fully deprotected products form potential targets for screening against C. albicans and may also result in new model structures for vaccine development.
- Polakova, Monika,Roslund, Mattias U.,Ekholm, Filip S.,Saloranta, Tiina,Leino, Reko
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experimental part
p. 870 - 888
(2009/07/17)
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- Synthesis of DIvalent 2,2′-linked mannose derivatives by homodimerization
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Several studies have implicated (1 → 2)-linked mannans as biologically relevant compounds. Recently, there has been a growing interest in the synthesis of multivalent carbohydrate assemblies due to their ability to target multiple receptors simultaneously. In the present work, a protective group strategy, based on the methodology originally developed by Crich, has been utilized for the homodimerization of olefinic carbohydrates, allowing a highly diastereoselective synthesis of some divalent structures. Furthermore, it is shown that divalent donors may undergo coupling reactions without losses in stereoselectivity or efficiency. The strategies described may potentially be applied to the synthesis of diverse neoglycoconjugates and oligosaccharides. Georg Thieme Verlag Stuttgart.
- Ekholm, Filip S.,Polakova, Monika,Pawlowicz, Agnieszka J.,Leino, Reko
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experimental part
p. 567 - 576
(2009/07/18)
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- Preparation of Thiosugars and Their Use
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A process for the preparation of a thiosaccharide represented by Saccharide-S-H wherein Saccharide comprises at least 4 sugar units, comprises subjecting a corresponding compound of the formula (P)Saccharide-S-(P) wherein (P) represents an O- or S-protecting group(s), to Birch reduction.
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Page/Page column 1
(2009/07/18)
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- Acyl group migration and cleavage in selectively protected β-D-galactopyranosides as studied by NMR spectroscopy and kinetic calculations
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The migration of acetyl, pivaloyl, and benzoyl protective groups and their relative stabilities at variable pH for a series of β-D-galactopyranoses were studied by NMR spectroscopy. The clockwise and counterclockwise migration rates for the different este
- Roslund, Mattias U.,Aitio, Olli,Waerna, Johan,Maaheimo, Hannu,Murzin, Dmitry Yu.,Leino, Reko
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supporting information; experimental part
p. 8769 - 8772
(2009/02/03)
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- Synthesis of the mixed acetal segment of S-glyceroplasmalopsychosine
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In this report the concept of converting carbohydrate to non-carbohydrate asymmetric molecules has been successfully exploited. The mixed acetal segment of glyceroplasmalopsychosine, a novel glycolipid, has been synthesized in a stereospecific manner using two simple sugar units. The glycosidation reaction between these two monosaccharides ensured the correct acetal stereocenter of the target molecule. Either olefin metathesis or heterogeneous Wittig reactions were used for constructing the long aliphatic chain of glyceroplasmalopsychosine.
- Parhi, Ajit K.,Mootoo, David R.,Franck, Richard W.
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scheme or table
p. 9821 - 9827
(2009/04/03)
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- REAGENTS AND METHODS FOR THE FORMATION OF DISULFIDE BONDS AND THE GLYCOSYLATION OF PROTEINS
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Methods and reagents for the formation of disulfide bonds, particularly in proteins, peptides and amino acids. The methods and reagents are particularly useful for the controlled glycosylation of proteins, peptides and amino acids. The methods utilise thiosulfonate or selenenylsulfide compounds as reagents or intermediates. Some proteins and peptides comprising selenenylsulfide groups also form part of the invention.
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Page/Page column 74-75
(2010/02/10)
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- Selectively protected galactose derivatives for the synthesis of branched oligosaccharides
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Synthesis and characterization of several new anomerically pure galactose derivatives, based on simple and effective protective group manipulations of benzyl β-D-galactopyranoside, are reported. The monosaccharides described contain selectively protected/deprotected hydroxyl functionalities at their 1,2,3,4- and 6-positions rendering them useful as building blocks for construction of branched oligosaccharides.
- Lehtil?, Reko L.,Lehtil?, Juho O.,Roslund, Mattias U.,Leino, Reko
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p. 3653 - 3661
(2007/10/03)
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- Elucidation of the mechanism of polysaccharide cleavage by chondroitin AC lyase from Flavobacterium heparinum
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Chondroitin AC lyase from Flavobacterium heparinum degrades chondroitin sulfate glycosaminoglycans via an elimination mechanism resulting in disaccharides or oligosaccharides with Δ4,5-unsaturated uronic acid residues at their nonreducing end. Mechanistic details concerning the ordering of the bond-breaking and -forming steps of this enzymatic reaction are nonexistent, mainly due to the inhomogeneous nature of the polymeric substrates. The creation of a new class of synthetic substrates for this enzyme has allowed the measurement of defined and reproducible kcat and Km values and has expanded the range of mechanistic studies that can be performed. The primary deuterium kinetic isotope effect upon kcat/Km for the abstraction of the proton α to the carboxylic acid was measured to be 1.67 ± 0.07, showing that deprotonation occurs in a rate-limiting step. Using substrates with leaving groups of differing reactivity, a flat linear free energy relationship was produced, indicating that the C4-O4 bond is not broken in a rate-determining step. Taken together, these results strongly suggest a stepwise mechanism. Consistent with this was the measurement of a secondary deuterium kinetic isotope effect upon kcat/Km of 1.01 ± 0.03 on a 4-{2H}-substrate, indicating that no sp2 character is developed at C4 during the rate-limiting step, thereby ruling out a concerted syn-elimination.
- Rye, Carl S.,Withers, Stephen G.
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p. 9756 - 9767
(2007/10/03)
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- A strategy for chemical synthesis of selectively methyl-esterified oligomers of galacturonic acid
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The synthesis of monomethyl-esterified trigalacturonans 1-3 is described as part of a general strategy towards pectic oligosaccharides. The necessary monomeric building blocks were all prepared on a large scale from galactose pentaacetate. The glycosylations were carried out between galactose glycosyl donors and acceptors using the n-pentenyl glycosylation technique. Yields of the desired α-anomers were in the 50 to 74% range. The trigalactans thus obtained were then subjected to oxidation at C-6. Depending on the protecting group at this position the oxidation either produced the carboxylic acid or the corresponding methyl ester. Hereby, oligomers of galacturonic acid can be prepared with methyl esters introduced in a regiocontrolled fashion.
- Clausen, Mads H.,Jorgensen, Malene R.,Thorsen, Jesper,Madsen, Robert
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p. 543 - 551
(2007/10/03)
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- Improved synthesis of 2,3:4,6-di-O-isopropylidene-D-glucopyranose and -D-galactopyranose
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2,3:4,6-Di-O-isopropylidene-D-glucopyranose and -D-galactopyranose acetals are conveniently prepared by hydrogenolysis of benzyl 2,3:4,6-di-O-isopropylidene-β-D-glucopyranose and -β-D-galactopyranose in almost quantitative yields in 3 h. This result is in contrast with the sluggish reaction observed (48 h) when the hydrogenolysis was carried out on either anomeric α,β mixtures or on the corresponding α anomers. Copyright (C) 1999 Elsevier Science Ltd.
- Gomez, Ana M.,Danelon, Gerardo O.,Valverde, Serafin,Lopez, J. Cristobal
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p. 138 - 142
(2007/10/03)
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- On the regioselectivity of the protease subtilisin towards the acylation of enantiomeric pairs of benzyl and naphthyl glycopyranosides. Part 2
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Subtilisin-catalyzed esterification of several enatiomeric benzyl and naphthyl glycopyranosides has been investigated. The D-sugar derivatives were all good substrates and subtilisin regioselectivity was similar with all the compounds tested, the 3-OH being acylated predominantly. On the other hand, most of the L-glycopyranosides were transformed during longer reaction times with a lower regioselectivity, the 2-OH being preferentially but not exclusively acylated.
- Danieli, Bruno,Peri, Francesco,Roda, Gabriella,Carrea, Giacomo,Riva, Sergio
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p. 2045 - 2060
(2007/10/03)
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- Glycosylation using 2-azido-3,4,6-tri-O-benzyl-2-deoxy-D-glucose, - galactose, and -mannose with the aid of p-nitrobenzenesulfonyl chloride- silver trifluoromethanesulfonate-triethylamine system
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This report describes a simple synthesis of 2-azido-3,4,6-tri-O-benzyl- 2-deoxy-D-glucopyranose. Glycosylation using this as well as 2-azido-3,4,6- tri-O-benzyl-2-deoxy-D-galactopyranose and -mannopyranose was achieved with the aid of a reagent system consisting of p-nitrobenzenesulfonyl chloride, silver trifluoromethanesulfonate, and triethylamine, and its modifications. O-(2-Acetamido-2-deoxy-β-D-glucopyranosyl)-(1 → 4)-O-α-D-mannopyranosyl- (1 → 4)-a-D-mannopyranose, the repeating unit of the main chain of the O- specific cell wall polysaccharide of E. coli 058 was synthesized.
- Koto, Shinkiti,Asami, Kazuyasu,Hirooka, Motoko,Nagura, Kazuo,Takizawa, Mizue,Yamamoto, Satoko,Okamoto, Nami,Sato, Mitsuko,Tajima, Hiromi,Yoshida, Toyosaku,Nonaka, Nobuo,Sato, Tadaaki,Zen, Shonosuke,Yago, Kazuo,Tomonaga, Fumiya
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p. 765 - 777
(2007/10/03)
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- A novel method for constructing β-D-mannosidic, 2-acetamido-2-deoxy-β-D-mannosidic and 2-deoxy-D-arabino-hexopyranosidic units from the bis(triflate) derivative of β-D-galactoside
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An efficient construction of the β-D-mannosidic, 2-acetamido-2-deoxy-β-D-mannosidic, 2-deoxy-2-fluoro-β-D-mannosidic, and 2-deoxy-β-D-arabino-hexopyranosidic units from the same intermediate, 2-4-bis(O-trifluoromethylsulfonyl) derivative of β-D-galactoside, was achieved in good yields in a stepwise inversion at C-4 and C-2 by using cesium acetate, n-Bu4NN3, n-Bu4NF, and n-Bu4NBH4. A convenient and practical protection of β-D-mannoside to the straightforward synthesis of antennary oligosaccharides was also achieved by using cesium trifluoroacetate.
- Sato,Yoshitomo,Takai
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p. 885 - 890
(2007/10/03)
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- A Novel Method for Constructions of β-D-Mannosidic, 2-Acetamido-2-deoxy-β-D-mannosidic, and 2-Deoxy-β-D-arabino-hexopyranosidic Units from the Bis(triflate) Derivative of β-D-Galactoside
-
The useful constructions of β-D-mannosidic, 2-acetamido-2-deoxy-β-D-mannosidic, and 2-deoxy-β-D-arabino-hexopyranosidic units from the same intermediate, 2,4-bis(O-trifluoromethanesulfonyl) derivative of β-D-galactoside, were achieved in a stepwise invers
- Sato, Ken-ichi,Yoshitomo, Akira
-
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- Syntheses of trehazolin derivatives and evaluation as glycosidase inhibitors
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The trehazolin derivatives 9-12 were synthesized from the aminocyclitol (7), which is the degradation product of trehazolin (5). In particular, compounds 9-11 were pseudodisaccharides that underwent replacement of the corresponding nonreducing D-glucose m
- Kobayashi,Shiozaki,Ando
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p. 2570 - 2580
(2007/10/02)
-
- Synthesis and biological activities of (4,6-di-O-phosphonato-β-D-mannopyranosyl)methylphosphonate as an analogue of 1L-myo-inositol 1,4,5-trisphosphate
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The synthesis of the α and β anomers of the title compound (1) was accomplished from D-mannose.In the key step, the phosphonate analogues of the mannopyranosyl phosphates were prepared by a direct Wadsworth-Emmons condensation of a protected mannose derivative (8) with tetraethyl methylenebisphosphonate under two-phase conditions.In vitro bioassays have shown that the β-anomer (1a) is a potent inhibitor of Ins(1,4,5)P3 3- kinase and inhibits other enzymes.
- Chung, Sung-Kee,Moon, Sung-Hwan
-
-
- Convenient Oxidative Debenzylation Using Dimethyldioxirane
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Substituted benzyl ethers are easily cleaved by their treatment with an excess of dimethyldioxirane; the corresponding alcohols are obtained in high yields.
- Csuk, Rene,Doerr, Petra
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p. 9983 - 9988
(2007/10/02)
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- CONVERSION OF D-MANNOSE INTO 1,5-ANHYDRO-D-ALLITOL-4,6-ACETONIDE; UNUSUAL INTRAMOLECULAR EPOXY ALCOHOL OPENING IN BASE
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Treatment of 3-tosyl-D-mannose-4,6-acetonide 9 with sodium borohydride affords an epoxy alcohol 11 which on treatment with base gives 1,5-anhydro-D-allitol-4,6-acetonide 15 by a 6-endo opening of the rearranged epoxy alcohol 13 rather than the product of
- Jung, Michael E.,Clevenger, Gary L.
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p. 6089 - 6092
(2007/10/02)
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- D-Galactose-derived D-galacturonic acid derivatives suitable as glycosyl acceptors
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Allyl (1a) and benzyl (1b) β-D-galactopyranosides were converted into methyl uronates, (6a and 6b) by three different routes.The carboxyl group was introduced by Jones oxidation of suitable protected precursors and esterified directly.The chemical behaviour of 6-O-trityl-, 6-O-(4,4'-dimethoxytrityl)-, and 6-O-(2-methoxypropane-2-yl)-derivatives was investigated.The overall yields obtained were strongly influenced by the protecting groups used, in particular their stability in acidic solution.
- Steffan, Wolfram,Vogel, Christian,Kristen, Helmut
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p. 109 - 120
(2007/10/02)
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- A Novel Strategy for the Synthesis of Ammonium 3-Deoxy-D-manno-2-octulosonate (Ammonium KDO) from Lower Monosaccharides. C-C Bond Construction at C6 of D-Mannose via Cobaloxime-Mediated Radical Alkyl-Alkenyl Cross Coupling
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Our synthesis of ammonium 3-deoxy-D-manno-2-octulosonate (ammonium KDO, 16) from D-mannose (3) proceeds in 10 one-flask operations in 1.5-1.6percent overall yield (66percent per operation).The strategic reaction is a C-C bond construction at C6 of D-mannose via photochemically induced radical cross coupling of α-ethoxyacrylonitrile with an alkyl cobaloxime derivative of D-mannose, in aqueous ethanol without protection of carbohydrate hydroxyls.In this paper we provide full experimental details of our KDO synthesis.In addition we provide some observations and insights on vanadium-catalyzed oxidations of α-hydroxy acids to α-keto acids.
- Branchaud, Bruce P.,Meier, Mark S.
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p. 1320 - 1326
(2007/10/02)
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- A SIMPLE STRATEGY FOR CHANGING THE REGIOSELECTIVITY OF GLYCOSIDASE-CATALYSED FORMATION OF DISACCHARIDES: PART II, ENZYMIC SYNTHESIS in situ OF VARIOUS ACCEPTOR GLYCOSIDES
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β-D-Galactosidase induced the formation of allyl, benzyl, and trimethylsilylethyl β-D-galactopyranosides on a 1-20-g scale from lactose and allyl alcohol, benzyl alcohol, and trimethylsilylethanol, respectively.Similarly, α-D-galactosidase catalysed the formation of allyl α-D-galactopyranoside from raffinose and allyl alcohol.The galactosides were used as acceptors for the preparation of the following disaccharide glycosides: β-D-Gal-(1->3)-β-D-Gal-OCH2CH=CH2, β-D-Gal-(1->6)-β-D-Gal-OCH2CH=CH2, β-D-Gal-(1->3)-β-D-Gal-OBn, β-D-Gal-(1->6)-β-D-Gal-OBn, β-D-Gal-(1->3)-β-D-Gal-OCH2CH2SiMe3, and α-D-Gal-(1->3)-α-D-Gal-OCH2CH=CH2.The β-D-galactosidase-catalysed reactions were efficient enough to allow the one pot preparation of the various β-linked mono- and digalactosides from lactose and alcohol.
- Nilsson, Kurt G. I.
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- THE SYNTHESIS OF THE HEPTOSE REGION OF THE GRAM-NEGATIVE BACTERIAL CORE OLIGOSACCHARIDES
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Disaccharides linked α(1-3) and α(1-7) and a trisaccharide linked α(1-7) and α(1-3) have been synthesized from suitably blocked L-glycero-D-mannoheptose derivatives using the trichloroacetimidate approach.
- Dziewiszek, Krzysztof,Banaszek, Anna,Zamojski, Aleksander
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p. 1569 - 1572
(2007/10/02)
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- SYNTHESIS OF THE α-MANNOSIDASE INHIBITORS SWAINSONINE AND 1,4-DIDEOXY-1,4-IMINO-D-MANNITOL FROM MANNOSE
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4-azido-4-deoxy-2,3-O-isopropylidene-α-D-mannopyranoside is a key intermediate in the syntheses of the α-mannosidase inhibitors, swainsonine and 1,4-dideoxy-1,4-imino-D-mannitol, and of the α-galactosidase inhibitor 1,4-dideoxy-1,4-imino-D-lyxitol, from mannose.
- Bashyal, Bharat P.,Fleet, George W. J.,Gough, Max J.,Smith, Paul W.
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p. 3083 - 3094
(2007/10/02)
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- NEW SYNTHESES OF D- AND L-GLYCERO-D-MANNO-HEPTOSES
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Three methods for the synthesis of the title compounds starting from benzyl 2,3,4-tri-O-benzyl-α-D-manno-hexodialdo-1,5-pyranoside (7) have been elaborated.Conversion of 7 into the cyanohydrin followed by reduction to give the amine and then deamination gave a derivative of L-glycero-D-manno-heptose in low yield.Condensation of 7 with 2-methylfuran gave two stereoisomeric 6-C-(2-methyl-5-furyl) derivatives.The preponderant stereoisomer was ozonised and then reduced to give a derivative of D-glycero-D-manno-heptose.Condensation of 7 with allyloxymethylmagnesium chloride gave derivatives of both heptoses in good yield and with an L-glycero-D-glycero ratio of 3.2:1.Deprotection of these derivatives gave the heptoses in high yield.
- Dziewiszek, Krzysztof,Zamoiski, Aleksander
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p. 163 - 172
(2007/10/02)
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- Synthesis of O-β-D-Galactopyranosyl-(1->4)-O-2-acetamido-2-deoxy-β-D-glucopyranosyl-(1->3)-D-mannose, a Postulated Trisaccharide of Human Erythrocyte Membrane Sialoglycoprotein
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Monoallylation of tributylstannylated benzyl 6-O-trityl-α-D-mannopyranoside (3) was efficiently catalysed by tetrabutylammonium bromide to give the 3-O- (4) and 2-O- (5) allyl ethers in 62 and 15percent yields, respectively.Compound (4) was converted into
- Alais, Jocelyne,Veyrieres, Alain
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p. 377 - 381
(2007/10/02)
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