142924-31-0Relevant articles and documents
A versatile approach to the synthesis of glycans containing mannuronic acid residues
Alex, Catherine,Visansirikul, Satsawat,Demchenko, Alexei V.
, p. 2731 - 2743 (2021/04/07)
Reported herein is a new method for a highly effective synthesis of β-glycosides from mannuronic acid donors equipped with the 3-O-picoloyl group. The stereocontrol of glycosylations was achieved by means of the H-bond-mediated aglycone delivery (HAD). The method was utilized for the synthesis of a tetrasaccharide linkedviaβ-(1 → 3)-mannuronic linkages. We have also investigated 3,6-lactonized glycosyl donors that provided moderate to high β-manno stereoselectivity in glycosylations. A method to achieve complete α-manno stereoselectivity with mannuronic acid donors equipped with 3-O-benzoyl group is also reported.
One-Pot Relay Glycosylation
Cai, Lei,Fang, Jing,Li, Ting,Song, Zejin,Sun, Jiuchang,Wan, Qian,Xiao, Xiong,Zeng, Jing
, p. 5498 - 5503 (2020/04/09)
A novel one-pot relay glycosylation has been established. The protocol is characterized by the construction of two glycosidic bonds with only one equivalent of triflic anhydride. This method capitalizes on the in situ generated cyclic-thiosulfonium ion as the relay activator, which directly activates the newly formed thioglycoside in one pot. A wide range of substrates are well-accommodated to furnish both linear and branched oligosaccharides. The synthetic utility and advantage of this method have been demonstrated by rapid access to naturally occurring phenylethanoid glycoside kankanoside F and resin glycoside merremoside D.
Synthesis of Glucuronoxylan Hexasaccharides by Preactivation-Based Glycosylations
B?hm, Maximilian,Madsen, Robert,Underlin, Emilie N.,d'Errico, Clotilde
supporting information, (2020/05/16)
The synthesis of two glucuronoxylans is described, which both consist of a pentaxylan backbone and a glucuronic acid linked to the 2 position in the fourth xylose residue from the reducing end. The two target molecules differ in the 4 position of the glucuronic acid where one is unsubstituted while the other contains a methyl ether. The pentaxylan backbone is assembled in four glycosylation reactions with phenyl thioglycoside donors. The couplings are performed by preactivation of the donor with in-situ-generated p-nitrobenzenesulfenyl triflate prior to addition of the acceptor. The glucuronic acids are then attached by Koenigs-Knorr glycosylations followed by deprotections. The syntheses employ a total of 8 steps from monosaccharide building blocks and afford the two glucuronoxylans in 12 and 15 % overall yield. The hexasaccharide products are valuable substrates for investigating the activity and specificity of glucuronoxylan-degrading enzymes.
Automated access to well-defined ionic oligosaccharides
Delbianco, Martina,Grafmüller, Andrea,Schiefelbein, Kevin,Seeberger, Peter H.,Tyrikos-Ergas, Theodore,Zhu, Yuntao
supporting information, p. 1349 - 1353 (2020/03/03)
Ionic polysaccharides are part of many biological events, but lack structural characterisation due to challenging purifications and complex synthesis. Four monosaccharides bearing modifications not found in nature are used for the automated synthesis of a collection of ionic oligosaccharides. Structural analysis reveals how the charge pattern affects glycan conformation.
Preparation method of clostridium bolteae surface capsular polysaccharide structure derivative
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, (2018/08/28)
The invention discloses a preparation method of a clostridium bolteae surface capsular polysaccharide structure derivative and belongs to the field of sugar chemistry. The preparation method comprisesthe following steps: taking glucose as a glycosyl donor to obtain a target beta-glycosidic bond; then successfully synthesizing a disaccharide building block through an oxidization-reduction glucoseC-2 site method; then synthesizing a target oligosaccharide structure which takes the disaccharide building block as a repeating unit, such as the gram-positive bacterium surface capsular polysaccharide structure derivative [arrow3]-alpha-D-Manp-(1arrow4)-beta-D-Rhap-(1arrow]5-Linker. A reducing end of decaose is connected with a connecting arm and is used for connecting protein to form a glycoconjugate for carrying out immunology researches. The method provided by the invention has the advantages of simplicity, time saving, labor saving and low cost; the obtained clostridium bolteae surface capsular polysaccharide structure derivative is possibly used for developing and preparing medicine related to autism.
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
Mukherjee, Mana Mohan,Basu, Nabamita,Chaudhury, Aritra,Ghosh, Rina
, p. 109301 - 109314 (2016/11/30)
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.
A Sugar-Based Gelator for Marine Oil-Spill Recovery
Vibhute, Amol M.,Muvvala, Venkatanarayana,Sureshan, Kana M.
supporting information, p. 7782 - 7785 (2016/07/07)
Marine oil spills constitute an environmental disaster with severe adverse effects on the economy and ecosystem. Phase-selective organogelators (PSOGs), molecules that can congeal oil selectively from oil–water mixtures, have been proposed to be useful for oil-spill recovery. However, a major drawback lies in the mode of application of the PSOG to an oil spill spread over a large area. The proposed method of using carrier solvents is impractical for various reasons. Direct application of the PSOG as a solid, although it would be ideal, is unknown, presumably owing to poor dispersion of the solid through the oil. We have designed five cheap and easy-to-make glucose-derived PSOGs that disperse in the oil phase uniformly when applied as a fine powder. These gelators were shown to selectively congeal many oils, including crude oil, from oil–water mixtures to form stable gels, which is an essential property for efficient oil-spill recovery. We have demonstrated that these PSOGs can be applied aerially as a solid powder onto a mixture of crude oil and sea water and the congealed oil can then be scooped out. Our innovative mode of application and low cost of the PSOG offers a practical solution to oil-spill recovery.
Blockwise synthesis of a pentasaccharide structurally related to the mannan fragment from the Candida albicans cell wall corresponding to the antigenic factor 6
Karelin,Tsvetkov, Yu. E.,Paulovi?ová,Paulovi?ová,Nifantiev
, p. 2942 - 2948 (2016/09/28)
A spacer-armed pentasaccharide structurally related to a fragment of the mannan from the cell wall of the fungus Candida albicans and corresponding to the antigenic factor 6 has been synthesized. This compound, comprising two α-(1→2)- and three β-(1→2)-li
High-yield total synthesis of (-)-strictinin through intramolecular coupling of gallates
Michihata, Naoki,Kaneko, Yuki,Kasai, Yusuke,Tanigawa, Kotaro,Hirokane, Tsukasa,Higasa, Sho,Yamada, Hidetoshi
, p. 4319 - 4328 (2013/06/27)
This paper describes a total synthesis of (-)-strictinin, an ellagitannin that is 1-O-galloyl-4,6-O-(S)-hexahydroxydiphenoyl (HHDP)-β-d-glucose. In the study, total efficiency of the synthesis was improved to produce a 78% overall yield in 13 steps from d-glucose. In the synthesis, formation of the 4,6-(S)-HHDP bridge including the 11-membered bislactone ring was a key step, in which intramolecular aryl-aryl coupling was adopted. The coupling was oxidatively induced by CuCl2-n-BuNH2 with perfect control of the axial chirality, and the reaction conditions of this coupling were optimized thoroughly to achieve the quantitative formation of the bridge.
'Naked' and hydrated conformers of the conserved core pentasaccharide of N-linked glycoproteins and its building blocks
Barry, Conor S.,Cocinero, Emilio J.,Carcabal, Pierre,Gamblin, David P.,Stanca-Kaposta, E. Cristina,Remmert, Sarah M.,Fernandez-Alonso, Maria C.,Rudic, Svemir,Simons, John P.,Davis, Benjamin G.
, p. 16895 - 16903 (2013/12/04)
N-glycosylation of eukaryotic proteins is widespread and vital to survival. The pentasaccharide unit -Man3GlcNAc2- lies at the protein-junction core of all oligosaccharides attached to asparagine side chains during this process. Although its absolute conservation implies an indispensable role, associated perhaps with its structure, its unbiased conformation and the potential modulating role of solvation are unknown; both have now been explored through a combination of synthesis, laser spectroscopy, and computation. The proximal -GlcNAc-GlcNAc- unit acts as a rigid rod, while the central, and unusual, -Man-β-1,4-GlcNAc- linkage is more flexible and is modulated by the distal Man-α-1,3- and Man-α-1,6- branching units. Solvation stiffens the 'rod' but leaves the distal residues flexible, through a β-Man pivot, ensuring anchored projection from the protein shell while allowing flexible interaction of the distal portion of N-glycosylation with bulk water and biomolecular assemblies.