Carbohydrate inhibitors of cholera toxin

• Vajinder Kumar and
• W. Bruce Turnbull

Beilstein J. Org. Chem. 2018, 14, 484–498, doi:10.3762/bjoc.14.34

• an IC50 value of 450 pM [63]. In another report Siegel and co-workers showed that corannulene-based pentavalent glycocluster 32 (Figure 13) bearing GM1os moieties possessed affinity for CT in low nanomolar range [64]. The IC50 value obtained was in the range of 5–25 nM. Fu et al. also synthesised and

Probing multivalency in ligand–receptor-mediated adhesion of soft, biomimetic interfaces

• Stephan Schmidt,
• Hanqing Wang,
• Daniel Pussak,
• Simone Mosca and
• Laura Hartmann

Beilstein J. Org. Chem. 2015, 11, 720–729, doi:10.3762/bjoc.11.82

• ligands are typically oligomers consisting of multiple subunits of varying complexity. When binding to receptors this leads to a receptor clustering or so-called glycocluster effect. However, multivalency even goes further: For example when cells form contact layers of surface anchored carbohydrates the

Synthesis of carbohydrate-scaffolded thymine glycoconjugates to organize multivalency

• Anna K. Ciuk and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2015, 11, 668–674, doi:10.3762/bjoc.11.75

• protecting group was observed whereas the Boc-protection remained untouched. Thus, the title glycocluster 13 was obtained in a single deprotection step. The new divalent glycoconjugate 13 shows good water solubility and is thus suited for biological testing. For photodimerization of 13, it was irradiated for

Synthesis of divalent ligands of β-thio- and β-N-galactopyranosides and related lactosides and their evaluation as substrates and inhibitors of Trypanosoma cruzi trans-sialidase

• María Emilia Cano,
• Rosalía Agusti,
• Alejandro J. Cagnoni,
• María Florencia Tesoriero,
• José Kovensky,
• María Laura Uhrig and
• Rosa M. de Lederkremer

Beilstein J. Org. Chem. 2014, 10, 3073–3086, doi:10.3762/bjoc.10.324

• equimolar concentration). The usefulness of the enzymatic trans-sialylation for the preparation of sialylated ligands was assessed by performing a preparative sialylation of a divalent substrate, which afforded the monosialylated compound as main product, together with the disialylated glycocluster

Expeditive synthesis of trithiotriazine-cored glycoclusters and inhibition of Pseudomonas aeruginosa biofilm formation

• Meriem Smadhi,
• Sophie de Bentzmann,
• Anne Imberty,
• Marc Gingras,
• Raoudha Abderrahim and
• Peter G. Goekjian

Beilstein J. Org. Chem. 2014, 10, 1981–1990, doi:10.3762/bjoc.10.206

• good affinity for Pseudomonas aeruginosa lectin lecA. They are convenient biological probes for investigating the roles of lecA and lecB in biofilm formation. Keywords: antibiotic; biofilm; glycocluster; lectin; multivalency effect; multivalent glycosystems; Introduction Pseudomonas aeruginosa (PA

• is often based on the recognition of multiple epitopes through a synergistic and cooperative effect, called the ‘’glycocluster effect” [14][15][16]. It has been shown in a number of systems that multivalency effects can be exploited to obtain high-avidity synthetic ligands against various types of

• dimethyldioxirane (DMDO) generated in situ in the presence of a phase-transfer catalyst, followed by treatment with NaN3 [39]. This afforded the silyl-protected D-galactose trithiotriazine–triazole glycocluster 11 under CuSO4/sodium ascorbate-catalyzed cycloaddition conditions [40] (20 °C, 24 h), in a satisfactory

Clicked and long spaced galactosyl- and lactosylcalix[4]arenes: new multivalent galectin-3 ligands

• Silvia Bernardi,
• Paola Fezzardi,
• Gabriele Rispoli,
• Stefania E. Sestito,
• Francesco Peri,
• Francesco Sansone and
• Alessandro Casnati

Beilstein J. Org. Chem. 2014, 10, 1672–1680, doi:10.3762/bjoc.10.175

• between the tetraalkyne calix[4]arene 8 and azido-galactoside 5 to give glycocluster 9 (83% yield) was carried out in DMF and H2O with CuSO4 and sodium ascorbate following a microwave-assisted procedure (20 min, 150 W, 80 °C). No partially functionalized compounds or other byproducts were detected in the

Photoswitchable precision glycooligomers and their lectin binding

• Daniela Ponader,
• Sinaida Igde,
• Marko Wehle,
• Katharina Märker,
• Mark Santer,
• David Bléger and
• Laura Hartmann

Beilstein J. Org. Chem. 2014, 10, 1603–1612, doi:10.3762/bjoc.10.166

• affinity carbohydrate ligands by displaying several monosaccharides/oligosaccharides on a protein scaffold or through a patch of lipids. This is known as the glycocluster effect or the multivalent presentation of sugar ligands [3][4]. This strategy can also be employed for the synthesis of carbohydrate

Synthesis and solvodynamic diameter measurements of closely related mannodendrimers for the study of multivalent carbohydrate–protein interactions

• Yoann M. Chabre,
• Alex Papadopoulos,
• Alexandre A. Arnold and
• René Roy

Beilstein J. Org. Chem. 2014, 10, 1524–1535, doi:10.3762/bjoc.10.157

• :0 to 90:10) afforded the desired glycocluster. Procedure B: Zemplén de-O-acetylation procedure for insoluble hydroxylated derivatives The acetylated compound was dissolved in anhydrous MeOH and a solution of sodium methoxide (1 M in MeOH, 5 µL every 20 min until precipitation) was added. An

• yield the fully deprotected glycocluster. Synthesis of peracetylated trivalent derivative 8: To a solution of triazido core 6 (50.0 mg, 109 μmol, 1.00 equiv) and mannoside 7 (158 mg, 409 μmol, 3.75 equiv) in a THF/H2O mixture (1:1, 6 mL) were added sodium ascorbate (19.4 mg, 98.1 μmol, 0.90 equiv) and

Bis(β-lactosyl)-[60]fullerene as novel class of glycolipids useful for the detection and the decontamination of biological toxins of the Ricinus communis family

• Hirofumi Dohi,
• Takeru Kanazawa,
• Akihiro Saito,
• Keita Sato,
• Hirotaka Uzawa,
• Yasuo Seto and
• Yoshihiro Nishida

Beilstein J. Org. Chem. 2014, 10, 1504–1512, doi:10.3762/bjoc.10.155

• interest [7][8]. In particular, multivalent biomaterials carrying more than two carbohydrate ligands have been designed [9][10][11][12][13][14][15] and proven to enhance protein–carbohydrate interactions by means of glycocluster effects [16][17][18]. More recently, our research group has reported on

High-affinity multivalent wheat germ agglutinin ligands by one-pot click reaction

• Henning S. G. Beckmann,
• Heiko M. Möller and
• Valentin Wittmann

Beilstein J. Org. Chem. 2012, 8, 819–826, doi:10.3762/bjoc.8.91

• sample of disaccharide 1 was eluted from a silica gel column for a second time. In comparison, the use of the less polar propargyl β-D-glucoside instead of 1 in the one-pot procedure with amine A4 led to the corresponding divalent glycocluster in a yield of 86% [48]. Finally, O-deacetylation of the

• divalent ligand C4 with its two chitobiose moieties occupying two adjacent binding sites of WGA. The linker is conformationally largely unrestricted and can adopt several low-energy conformations. WGA chain 1 is colored yellow, chain 2 is blue. Synthesis of glycocluster B5 with isolation of the

Synthesis of heteroglycoclusters by using orthogonal chemoselective ligations

• Baptiste Thomas,
• Michele Fiore,
• Isabelle Bossu,
• Pascal Dumy and
• Olivier Renaudet

Beilstein J. Org. Chem. 2012, 8, 421–427, doi:10.3762/bjoc.8.47

• observed that a tetravalent glycocluster can be obtained in good yields and as a unique 1,4-regioisomer by using a catalytic amount of copper micropowder in a mixture of isopropanol and ammonium acetate buffer [42]. Therefore we decided to follow similar conditions in this study with propargyl glycosides