- Synthesis of optically pure, differentially protected 1,4- and 1,6-mannosyl-D-myo-inositol derivatives from 7-oxabicyclo[2.2.1]heptan-2-one
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Efficient procedures to prepare 4-O-mannosyl conduritol B derivatives from mannosyl oxanorbornanes are described. The osmium-catalyzed cis-dihydroxylation of the corresponding 1-O-acetates displays high π-facial selectivity syn to the acetate functionalit
- Arjona, Odon,De Dios, Alfonso,Montero, Carlos,Plumet, Joaqufn
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Read Online
- Deuterium labelling to extract local stereochemical information by VCD spectroscopy in the C-D stretching region: A case study of sugars
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Stereochemical elucidation of molecules with multiple chiral centers is difficult. Even with VCD spectroscopy, excluding all but one diastereomeric structural candidate is challenging because the stereochemical inversion of one chiral center among many centers does not always result in noticeable differences in their VCD spectra. This work demonstrates that the introduction of a suitable VCD chromophore with absorption in the 2300-1900 cm-1 region can be used for extracting local stereochemical information and for the stereochemical assignment of the C-1 position of various sugars as a case study. Through studies on a series of epimeric pairs of monosaccharides and their derivatives, we found that the introduction of one -OCD3 group to each C-1 position produced almost mirror-image VCD patterns in the 2300-1900 cm-1 region depending on the C-1 stereochemistry irrespective of the other molecular moieties. This work also shows that comparison of the observed VCD signals and the calculated ones enables the stereochemical assignment of a chiral center in the vicinity of the chromophore. This study provides a proof of concept that the use of a VCD chromophore in the 2300-1900 cm-1 region enables the analysis of selected stereochemistry of suitable molecular systems. Further studies on this concept should lead to the development of a method useful for the structural elucidation of other types of complex molecules.
- Abdelrasoul, Mariam,Abe, Yoshihiro,Maulida, Nurul Fajry,Monde, Kenji,Nakamura, Yuta,Taniguchi, Tohru,Zubir, Mohamad Zarif Mohd
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supporting information
p. 1067 - 1072
(2022/02/11)
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- Stereoselective O-Glycosylations by Pyrylium Salt Organocatalysis**
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Despite many years of invention, the field of carbohydrate chemistry remains rather inaccessible to non-specialists, which limits the scientific impact and reach of the discoveries made in the field. Aiming to increase the availability of stereoselective
- Nielsen, Michael Martin,Holmstr?m, Thomas,Pedersen, Christian Marcus
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- Synthesis of Glycosyl Fluorides by Photochemical Fluorination with Sulfur(VI) Hexafluoride
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This study describes a new convenient method for the photocatalytic generation of glycosyl fluorides using sulfur(VI) hexafluoride as an inexpensive and safe fluorinating agent and 4,4′-dimethoxybenzophenone as a readily available organic photocatalyst. This mild method was employed to generate 16 different glycosyl fluorides, including the substrates with acid and base labile functionalities, in yields of 43%-97%, and it was applied in continuous flow to accomplish fluorination on an 7.7 g scale and 93% yield.
- Bannykh, Anton,Khomutnyk, Yaroslav,Kim, Sungjin,Nagorny, Pavel
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p. 190 - 194
(2021/01/13)
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- Total Synthesis of Phospholipomannan of Candida albicans
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First, total synthesis of the cell surface phospholipomannan anchor [β-Manp-(1 → 2)-β-Manp]n-(1 → 2)-β-Manp-(1 → 2)-α-Manp-1 → P-(O → 6)-α-Manp-(1 → 2)-Inositol-1-P-(O → 1)-phytoceramide of Candida albicans is reported. The target phospholipomannan (PLM) anchor poses synthetic challenges such as the unusual kinetically controlled (1 → 2)-β-oligomannan domain, anomeric phosphodiester, and unique phytoceramide lipid tail linked to the glycan through a phosphate group. The synthesis of PLM anchor was accomplished using a convergent block synthetic approach using three main appropriately protected building blocks: (1 → 2)-β-tetramannan repeats, pseudodisaccharide, and phytoceramide-1-H-phosphonate. The most challenging (1 → 2)-β-tetramannan domain was synthesized in one pot using the preactivation method. The phytoceramide-1-H-phosphonate was synthesized through an enantioselective A3 three-component coupling reaction. Finally, the phytoceramide-1-H-phosphonate moiety was coupled with pseudodisaccharide followed by deacetylation to produce the acceptor, which on subsequent coupling with tetramannosyl-H-phosphonate provided the fully protected PLM anchor. Final deprotection was successfully achieved by Pearlman's hydrogenation.
- Ali, Asif,Gannedi, Veeranjaneyulu,Singh, Parvinder Pal,Vishwakarma, Ram A.
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p. 7757 - 7771
(2020/07/25)
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- Total Synthesis of Tiacumicin B: Implementing Hydrogen Bond Directed Acceptor Delivery for Highly Selective β-Glycosylations
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A total synthesis of tiacumicin B, a natural macrolide whose remarkable antibiotic properties are used to treat severe intestinal infections, is reported. The strategy is in part based on the prior synthesis of the tiacumicin B aglycone, and on the decisive use of sulfoxides as anomeric leaving groups in hydrogen-bond-mediated aglycone delivery (HAD). This new HAD variant permitted highly β-selective rhamnosylation and noviosylation. To increase convergence, the rhamnosylated C1–C3 fragment thus obtained was anchored to the C4–C19 aglycone fragment by adapting the Suzuki–Miyaura cross-coupling used for the aglycone synthesis. Ring-size-selective macrolactonization provided a compound engaged directly in the noviolysation step with virtually total β selectivity. The final efficient removal of all the protecting groups provided synthetic tiacumicin B.
- Beau, Jean-Marie,Fran?ois-Eude, Marc,Genta-Jouve, Grégory,Jeanne-Julien, Louis,Masson, Guillaume,Norsikian, Stéphanie,Roulland, Emmanuel,Servajean, Vincent,Tresse, Cedric
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p. 6612 - 6616
(2020/03/03)
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- A Synthetic Carbohydrate-Protein Conjugate Vaccine Candidate against Klebsiella pneumoniae Serotype K2
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Klebsiella pneumoniae causes pneumonia and liver abscesses in humans worldwide and contains virulence factor capsular polysaccharides and lipopolysaccharides linked to the cell wall. Although capsular polysaccharides are good antigens for vaccine producti
- Ravinder, Mettu,Liao, Kuo-Shiang,Cheng, Yang-Yu,Pawar, Sujeet,Lin, Tzu-Lung,Wang, Jin-Town,Wu, Chung-Yi
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p. 15964 - 15997
(2020/11/13)
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- Synthesis and cellular uptake of carbamoylated mannose derivatives
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A series of 3-carbamoyl- and 2,3-dicarbamoyl-mannose derivatives were synthesized, conjugated to a fluorescent dye (Cy5GE, AF 647 or NBD) and their cellular uptake in A549 and THP-1 cell lines was studied by FACS. In contrast to earlier studies on carbamoyl mannosides, the observed uptake was not related to carbamoyl group on the mannose residue but rather to the cyanine dye attached, a trend previously observed for Cy5-fructose conjugates. The NBD-conjugates however, showed a temperature and concentration dependent uptake in case of mannose conjugates. These results suggest a profound impact of the dye which should be taken into consideration when studying the uptake of small molecules by dye conjugation.
- Elferink, Hidde,Geurts, Kim,Jue, Stijn,MacCormick, Somhairle,Veeneman, Gerrit,Boltje, Thomas J.
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- ANTIBODY CONJUGATES AND METHODS OF MAKING THE ANTIBODY CONJUGATES
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Described herein are antibody conjugates and methods of making antibody conjugates.
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- Efficient one-pot per-: O -acetylation-thioglycosidation of native sugars, 4,6- O -arylidenation and one-pot 4,6- O -benzylidenation-acetylation of S -/ O -glycosides catalyzed by Mg(OTf)2
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A sequential one-pot per-O-acetylation-S-/O-glycosidation of native mono and disaccharides under solvent free conditions using 0.5 mole% of Mg(OTf)2 as a non-hygroscopic, recyclable catalyst is reported. Regioselective 4,6-O-arylidenation of glycosides and thioglycosides with benzaldehyde or p-methoxybenzaldehyde dimethyl acetal is catalyzed by 10 mole% of Mg(OTf)2 to produce the corresponding 4,6-O-arylidenated product in high yields. Mg(OTf)2 can also mediate sequential one-pot benzylidenation-acetylation of mono and disaccharide based glycosides and thioglycosides in high yield.
- Mukherjee, Mana Mohan,Basu, Nabamita,Chaudhury, Aritra,Ghosh, Rina
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p. 109301 - 109314
(2016/11/30)
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- The composite body deproteinizing chitosanoligosaccharide-
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Provided herein are conjugates comprising a protein and an oligosaccharide of one of Formulae I-VI. Also provided herein are pharmaceutical compositions comprising such conjugates. Further provided herein are methods of treating a lysosomal storage disorder in a mammal by administration of an oligosaccharide-glycoprotein conjugate.
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- The chemoselective O-glycosylation of alcohols in the presence of a phosphate diester and its application to the synthesis of oligomannosylated phosphatidyl inositols
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Abstract The glycosylation of hydroxyl groups in the presence of a phosphate diester and its use in the synthesis of oligomannosylated phosphatidiyl inositols are reported. Using a catalytic amount of TMSOTf as an activator for the glycosidation of glycosyl imidates in the presence of a primary alcohol and a phosphate diester provided the desired glycoside along with a glycosyl phosphnate. Complete glycosylation of the primary alcohol required a stoichiometric amount of TMSOTf or TBSOTf. We next examined an application of the method to the synthesis of the phosphatidylinositol mannosides, which are components in the mycobacterial cell wall envelope. Glycosylation of the primary alcohol at the C6 position of a 2,6-dimannosyl myo-inositol core containing a diacylated phosphatidyl lipid with glycosyl imidiates proceeded smoothly to provide multimannosylated inositol derivatives in good yields. However, the 4,6 diol mannoside was a poor acceptor in this reaction.
- Ohira, Shuichi,Yamaguchi, Yoshiki,Takahashi, Takashi,Tanaka, Hiroshi
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p. 6602 - 6611
(2015/08/18)
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- Synthesis and conformational analysis of phosphorylated β-(1→2) linked mannosides
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Phosphorylated β-(1→2)-oligomannosides are found on the cell surface of several Candida species, including Candida albicans (an opportunistic pathogen). These molecules are believed to take part in the invasion process of fungal infections, which in the case of C. albicans can lead to severe bloodstream infections and death, and can therefore be considered important from a biological standpoint. Understanding the mechanism of their action requires access to the corresponding oligosaccharide model compounds in pure form. In the present work, synthesis of the model core structures involved in the invasion process of C. albicans, consisting of phosphorylated β-(1→2)-linked mannotriose and tetraose, is reported. In order to elucidate the nature of these molecules in more detail, an extensive NMR-spectroscopic study encompassing complete spectral characterization, conformational analysis and molecular modelling was performed. The obtained results were also compared to similar chemical entities devoid of the charged phosphate group.
- Rahkila, Jani,Ekholm, Filip S.,Panchadhayee, Rajib,Arda, Ana,Canada, Francisco Javier,Jimenez-Barbero, Jesus,Leino, Reko
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- Chemical synthesis of asparagine-linked archaeal N-glycan from Methanothermus fervidus
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Several N-linked glycoproteins have been identified in archaea and there is growing evidence that the N-glycan is involved in survival and functioning of archaea in extreme conditions. Chemical synthesis of the archaeal N-glycans represents a crucial step
- Sanapala, Someswara Rao,Kulkarni, Suvarn S.
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supporting information
p. 3578 - 3583
(2014/04/03)
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- Carbene-mediated functionalization of the anomeric C-H bond of carbohydrates: Scope and limitations
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Herein we investigate the scope and limitations of a new synthetic approach towards α- and β-ketopyranosides relying on the functionalization of the anomeric C-H bond of carbohydrates by insertion of a metal carbene. A key bromoacetate grafted at the 2-position is the cornerstone of a stereoselective glycosylation/diazotransfer/quaternarization sequence that makes possible the construction of a quaternary center with complete control of the stereochemistry. This sequence shows a good tolerance toward protecting groups commonly used in carbohydrate chemistry and gives rise to quaternary disaccharides with good efficiency. In the case of a disaccharide with a more restricted conformation, this functionalization process can be hampered by the steric demand next to the targeted anomeric position. In addition, the formation of transient orthoesters during the glycosylation step may also reduce the overall efficiency of the synthetic sequence. Copyright
- Boultadakis-Arapinis, Mélissa,Prost, Elise,Gandon, Vincent,Lemoine, Pascale,Turcaud, Serge,Micouin, Laurent,Lecourt, Thomas
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p. 6052 - 6066
(2013/06/27)
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- FeCl3 mediated arylidenation of carbohydrates
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Glycosides and thioglycosides based on monosaccharides in reaction with benzaldehyde dimethylacetal or p-methoxybenzaldehyde dimethyl acetal undergo FeCl3-catalyzed (20 mol %) regioselective 4,6-O-arylidenation producing the corresponding acetals in high yields. FeCl3 also mediates acetalation of glycosides and thioglycosides of cellobiose, maltose, and lactose affording the corresponding 4′,6′-O-benzylidene acetals, which were isolated after their acetylation in situ with acetic anhydride and pyridine. The combined yields (two steps) of these final products are also high (61-84%). The procedure is applicable to a wide variety of functional groups including -OBn.
- Basu, Nabamita,Maity, Sajal K.,Roy, Soumik,Singha, Shuvendu,Ghosh, Rina
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experimental part
p. 534 - 539
(2011/04/27)
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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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- Synthesis of the repeating trisaccharide unit of the cell wall lipopolysaccharide of Escherichia coli type 8
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NIS/TfOH mediated glycosidation of methyl 3,4,6-tri-O-benzyl-α-d-mannopyranoside with phenyl 2-O-acetyl-3,4,6-tri-O-benzyl-1-thio-α-d-mannopyranoside furnished the corresponding disaccharide derivative in excellent yield and α-selectivity. Ze?mplen deacet
- Maity, Sajal K.,Maity, Swarupananda,Patra, Amarendra,Ghosh, Rina
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scheme or table
p. 5847 - 5849
(2009/04/05)
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- PROCESS FOR PRODUCING 1,2-TRANS-GLYCOSIDE COMPOUND
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In preparing a glycoside compound from (a) a furanose compound or pyranose compound, and (b) an alcohol compound, a process for preparing a glycoside compound in which glycosidic bond locates selectively trans form relative to C-2 hydroxyl group, the proc
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Page/Page column 9
(2010/11/28)
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- Synthetic yeast oligomannosides as biological probes: α-D-Manp (1→3) α-D-Manp (1→2) α-D-Manp and α-D-Manp (1→3) α-D-Manp (1→2) α-D-Manp (1→2) α-D-Manp as Crohn's disease markers
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The anti-Saccharomyces cerevisiae antibodies (ASCA) are markers for Crohn's disease used for diagnostic, phenotypic characterization and sero-epidemiological studies. Antibody detection is made by different immunoenzymatic tests using S. cerevisiae mannans which are both complex and poorly standardized antigens. Here we construct the major discriminating epitopes comprised within this antigen. When coupled to linker arm and a peptidic carrier to functionalize microtiter plates, they were able to discriminate serological responses between Crohn's disease and ulcerative colitis, another form of inflammatory bowel disease.
- Chevalier, Reynald,Esnault, Jacques,Vandewalle, Peggy,Sendid, Boualem,Colombel, Jean-Frédéric,Poulain, Daniel,Mallet, Jean-Maurice
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p. 7669 - 7677
(2007/10/03)
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- Direct chemical synthesis of the β-mannans: Linear and block syntheses of the alternating β-(1→3)-β-(1→4)-mannan common to Rhodotorula glutinis, Rhodotorula mucilaginosa, and Leptospira biflexa
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Two stereocontrolled syntheses of a methyl glycoside of an alternating β-(1→4)-β-(1→3)-mannohexaose, representative of the mannan from Rhodotorula glutinis, Rhodotorula mucilaginosa, and Leptospira biflexa, are described. Both syntheses employ a combinati
- Crich, David,Li, Wenju,Li, Hongmei
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p. 15081 - 15086
(2007/10/03)
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- A synthetic approach to the glycan chain of high mannose type N-glycoprotein
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The syntheses of α-D-glucopyranose-(1→3)-D-mannopyranose, methyl α-D-glucopyranose-(1→3)-α-D-mannopyranoside and methyl α-D-glucopyranose-(1→3)-α-D-mannopyranose-(1→2)-α-D- mannopyranoside are reported. High stereoselectivity was observed during the coupl
- Cherif, Slim,Clavel, Jean-Marc,Monneret, Claude
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p. 1203 - 1218
(2007/10/03)
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- Synthesis of 2-O-(3-O-carbamoyl-α-D-mannopyranosyl)-L-gulopyranose: Sugar moiety of antitumor antibiotic bleomycin
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A new route to the disaccharide moiety (2-O-(3-O-carbamoyl-α-D-mannopyranosyl)-L-gulopyranose) of the antitumor agent bleomycin was developed. Both the L-gulose synthon 21 and the 3-O-carbamoyl-D-mannose segment 30 were prepared from D-mannose in a regioselective manner by applying stannylene acetal methodology. Glycosylation of 21 with 30 proceeded smoothly, and further conversion to disaccharide derivatives (33 and 34) was successfully accomplished.
- Oshitari, Tetsuta,Shibasaki, Masakatsu,Yoshizawa, Takeshi,Tomita, Masahiro,Takao, Ken-Ichi,Kobayashi, Susumu
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p. 10993 - 11006
(2007/10/03)
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- Preparation of 2-O-(3-O-carbamoyl-α-D-mannopyranosyl)-L-gulopyranose: Synthetic study on the sugar moiety of antitumor antibiotic bleomycin
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A new practical route to the disaccharide moiety of bleomycin was developed. Both of key building blocks 9 and 16 were prepared from D-mannose in a regioselective manner by applying stannylene acetal methodology. Glycosylation of the allyl alcohol 9 with the trichloroacetimidate 16 proceeded smoothly, and the further incorporation to the disaccharide moiety was succesfully accomplished.
- Oshitari,Kobayashi
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p. 1089 - 1092
(2007/10/02)
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- Synthesis of aliphatic O-dimannosyl amino acid building blocks for solid-phase assembly of glycopeptide libraries
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The preparations of α(1,2)-, α(1,3)- and α(1,6)-linked mannose disaccharides is described.The protected α-D-Man(1-->3)-D-Man disaccharide was synthesized using the trichloroacetimidate method, while the Koenigs-Knorr procedure was employed in the preparation of the 1-->2- and 1-->6-linked disaccharides.Glycosylation of NΑ-Fmoc-Ser-OPfp , Nα-Fmoc-Thr-OPfp and Nα-Fmoc-Hyp-OPfp with the dimannosyl bromides afforded the activated building blocks, in moderate to high yield, for direct use in solid-phase synthesis of glycopeptide libraries.
- Franzyk, Henrik,Meldal, Morten,Paulsen, Hans,Bock, Klaus
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p. 2883 - 2898
(2007/10/02)
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- New method for the preparation of L-gulose from D-mannose: Synthetic study on the sugar moiety of bleomycin
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L-gulose, a key building block of the carbohydrate moiety of antitumor antibiotic bleomycins, is prepared from D-mannose by the inversion at C-5.
- Oshitari, Tetsuta,Tomita, Masahiro,Kobayashi, Susumu
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p. 6493 - 6494
(2007/10/02)
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