35526-05-7Relevant articles and documents
Discriminating non-ylidic carbon-sulfur bond cleavages of sulfonium ylides for alkylation and arylation reactions
Fang, Jing,Li, Ting,Ma, Xiang,Sun, Jiuchang,Cai, Lei,Chen, Qi,Liao, Zhiwen,Meng, Lingkui,Zeng, Jing,Wan, Qian
, p. 288 - 292 (2021/07/25)
A sulfonium ylide participated alkylation and arylation under transition-metal free conditions is described. The disparate reaction pattern allowed the separate activation of non-ylidic S-alkyl and S-aryl bond. Under acidic conditions, sulfonium ylides serve as alkyl cation precursors which facilitate the alkylations. While under alkaline conditions, cleavage of non-ylidic S-aryl bond produces O-arylated compounds efficiently. The robustness of the protocols were established by the excellent compatibility of wide variety of substrates including carbohydrates.
Total Synthesis of the Congested, Bisphosphorylated Morganella morganii Zwitterionic Trisaccharide Repeating Unit
Keith, D. Jamin,Townsend, Steven D.
, p. 12939 - 12945 (2019/08/22)
Zwitterionic polysaccharides (ZPSs) activate T-cell-dependent immune responses by major histocompatibility complex class II presentation. Herein, we report the first synthesis of a Morganella morganii ZPS repeating unit as an enabling tool in the synthesis of novel ZPS materials. The repeating unit incorporates a 1,2-cis-α-glycosidic bond; the problematic 1,2-trans-galactosidic bond, Gal-β-(1 → 3)-GalNAc; and phosphoglycerol and phosphocholine residues which have not been previously observed together as functional groups on the same oligosaccharide. The successful third-generation approach leverages a first in class glycosylation of a phosphoglycerol-functionalized acceptor. To install the phosphocholine unit, a highly effective phosphocholine donor was synthesized.
Synthetic MUC1 antitumor vaccine with incorporated 2,3-sialyl-T carbohydrate antigen inducing strong immune responses with isotype specificity
Stra?burger, David,Glaffig, Markus,Stergiou, Natascha,Bialas, Sabrina,Besenius, Pol,Schmitt, Edgar,Kunz, Horst
, p. 1142 - 1146 (2018/10/21)
The endothelial glycoprotein MUC1 is known to underlie alterations in cancer by means of aberrant glycosylation accompanied by changes in morphology. The heavily shortened glycans induce a collapse of the peptide backbone and enable accessibility of the latter to immune cells, rendering it a tumor-associated antigen. Synthetic vaccines based on MUC1 tandem repeat motifs, comprising tumor-associated 2,3-sialyl-T antigen, conjugated to the immunostimulating tetanus toxoid, are reported herein. Immunization with these vaccines in a simple water/oil emulsion produced a strong immune response in mice to which stimulation with complete Freund’s adjuvant (CFA) was not superior. In both cases, high levels of IgG1 and IgG2a/b were induced in C57BL/6 mice. Additional glycosylation in the immunodominant PDTRP domain led to improved binding of the induced antisera to MCF-7 breast tumor cells, compared with that of the monoglycosylated peptide vaccine.
C-Glycosyl amino acids through hydroboration-cross-coupling of exo-glycals and their application in automated solid-phase synthesis
Koch, Stefan,Schollmeyer, Dieter,L?we, Holger,Kunz, Horst
, p. 7020 - 7041 (2013/07/05)
O-Glycosylation is one of the most important post-translational modifications of proteins. The attachment of carbohydrates to the peptide backbone influences the conformation as well as the solubility of the conjugates and can even be essential for binding to specific ligands in cell-cell interactions or for active transport over membranes. This makes glycopeptides an interesting class of compounds for medical applications. To enhance the long-term availability of these molecules in vivo, the stabilization of the glycosidic bond between the amino acid residue and the carbohydrate is of interest. The described modular approach affords β-linked C-glycosyl amino acids by a sequence of Petasis olefination of glyconolactones, stereoselective hydroboration and a mild B-alkyl-Suzuki coupling reaction. The coupling products were transformed to C-glycosyl amino acid building-blocks suitable for solid-phase synthesis and successfully incorporated into a partial sequence of the tumor-associated MUC1-glycopeptide. The resulting C-glycopeptides are candidates for the development of long-term stable mimics of O-glycopeptide vaccines. Copyright
1,2;3,4-Di-O-isopropylidene-l-galactose synthesis from its d-enantiomer
Doboszewski, Bogdan,Herdewijn, Piet
experimental part, p. 2253 - 2256 (2012/05/20)
Easy procedure was devised to obtain di-O-isopropylidene-l-galactose from di-O-isopropylidene-d-galactose.
A new approach to explore the binding space of polysaccharide-based ligands: Selectin antagonists
Calosso, Mickael,Charpentier, Daniel,Vaillancourt, Marc,Bencheqroun, Mohammed,St-Pierre, Gabrielle,Wilkes, Brian C.,Guindon, Yvan
supporting information, p. 1045 - 1049 (2013/02/22)
The discovery of molecules that interfere with the binding of a ligand to a receptor remains a topic of great interest in medicinal chemistry. Herein, we report that a monosaccharide unit of a polysaccharide ligand can be replaced advantageously by a conformationally locked acyclic molecular entity. A cyclic component of the selectin ligand Sialyl Lewisx, GlcNAc, is replaced by an acyclic tether, tartaric esters, which link two saccharide units. The conformational bias of this acyclic tether originates from the minimization of intramolecular dipole-dipole interaction and the gauche effect. The evaluation of the binding of these derivatives to P-selectin was measured by surface plasmon resonance spectroscopy. The results obtained in our pilot study suggest that the discovery of tunable tethers could facilitate the exploration of the carbohydrate recognition domain of various receptors.
Efficient and convenient heterogeneous palladium-catalyzed regioselective deuteration at the benzylic position
Kurita, Takanori,Hattori, Kazuyuki,Seki, Saori,Mizumoto, Takuto,Aoki, Fumiyo,Yamada, Yuki,Ikawa, Kanoko,Maegawa, Tomohiro,Monguchi, Yasunari,Sajiki, Hironao
, p. 664 - 673 (2008/12/21)
The Pd/C-catalyzed efficient and regioselective hydrogen-deuterium (H-D) exchange reaction on the benzylic site proceeded in D2O in the presence of a small amount of H2 gas. The use of the Pd/C-ethylenediamine complex [Pd/C(en)] as a catalyst instead of Pd/C led to the efficient deuterium incorporation into the benzylic site of Obenzyl protective groups without hydrogenolysis. These H-D exchange reactions provide a post synthetic and D2-gas-free deuterium-labeling method on a wide variety of benzylic sites using D2O as the deuterium source and heterogeneous Pd/C or Pd/C(en) as a reusable heterogeneous palladium catalyst under mild and neutral conditions.
Synthesis of a tumor-associated 2,3-sialyl-T glycododecapeptide antigen from the tandem repeat region of the mucin MUC1
Dziadek, Sebastian,Kunz, Horst
, p. 1623 - 1626 (2007/10/03)
As a cell surface antigen for the development of selective antitumor vaccines, a tumor-associated glycododecapeptide from epithelial MUC1 carrying the 2,3-sialyl-T antigen was synthesized. The 2,3-ST building block was assembled from a TN-threo
Syntheses of novel photoaffinity probes for bioorganic studies on nyctinasty of leguminous plants
Sugimoto, Takanori,Fujii, Tomohiko,Hatanaka, Yasumaru,Yamamura, Shosuke,Ueda, Minoru
, p. 6529 - 6532 (2007/10/03)
Novel and non-radioactive photoaffinity probes (1 and 2) for the bioorganic study of nyctinasty are designed and synthesized based on potassium isolespedezate (3), which induce leaf-opening against the leaf of Cassia mimosoides L. These probes bear a trifluoromethyldiazirine or diazophenyl group for photoaffinity and a biotin subunit for affinity chromatography and chemiluminescent detection. Probes (1 and 2) showed leaf-opening activity at 5×10-5 mol/L with leaves of C. mimosoides; thus, they would be an important tool for the identification of a receptor protein for 3.
Chemical synthesis of sulfated oligosaccharides with a β-D-Gal-(1→3)-[β-D-Gal-(1→4)-(α-L-Fuc-(1→3)-β-D-GlcNAc-(1→6)]-α-D -GalNAc sequence
Xia, Jie,Srikrishnan,Alderfer, James L.,Jain,Piskorz, Conrad F.,Matta, Khushi L.
, p. 561 - 577 (2007/10/03)
The syntheses of two sulfated pentasaccharides: β-D-Gal6SO3Na-(1→3)-[β-D-Gal-(1→4)-α-L-Fuc-(1→3)-β-D-GlcNAc-(1→6) ]-α-D-GalNAc→OMe (1) and β-D-Gal6SO3Na-(1→3)-[β-D-Gal-(1→4)-α-L-Fuc-(1→3)-β-D-GlcNAc6SO3Na -(1→6)]-α-D-GalNA