Chemo-enzymatic modification of poly-N-acetyllactosamine (LacNAc) oligomers and N,N-diacetyllactosamine (LacDiNAc) based on galactose oxidase treatment

• Christiane E. Kupper,
• Ruben R. Rosencrantz,
• Birgit Henßen,
• Helena Pelantová,
• Stephan Thönes,
• Anna Drozdová,
• Vladimir Křen and
• Lothar Elling

Beilstein J. Org. Chem. 2012, 8, 712–725, doi:10.3762/bjoc.8.80

• of glycoconjugates with hydrazide or hydroxylamine reagents [30][31][32][33][34], coupling with amino-modified glycan moieties [35], chemical oxidation of the carbonyl to a carboxyl group in the synthesis of immunoreactive neo-glycosaminoglycans [12], and the synthesis of deoxysugars [36], have been

• summary, these novel neo-glycoconjugates are interesting tools for extensive binding studies of a variety of glycan binding proteins (lectins, antibodies) and for possible therapeutic applications. Conclusion Novel poly-LacNAc derivatives have been produced on a micro-gram scale, which can be used for

• class of neo-glycoconjugates. We here also demonstrate, for the first time, that poly-LacNAc oligomers with terminal galactose 6-aldehyde moieties are substrates for glycosyltransferases. In this way, further poly-LacNAc glycans carrying terminal and/or internal galactose 6-aldehyde units can be built

Synthesis and biological evaluation of nojirimycin- and pyrrolidine-based trehalase inhibitors

• Davide Bini,
• Francesca Cardona,
• Matilde Forcella,
• Camilla Parmeggiani,
• Paolo Parenti,
• Francesco Nicotra and
• Laura Cipolla

Beilstein J. Org. Chem. 2012, 8, 514–521, doi:10.3762/bjoc.8.58

• potential fungicides or antibiotics [13], such as trehalostatin (4) [1][14] and some iminosugar glycoconjugates, e.g., 5 or MDL 25,637 (6) [1][15][16] (Figure 1). In this work we report the synthesis and the biological activity of a small set of nojirimycin- and pyrrolidine-based iminosugar derivatives and

Synthesis in the glycosciences II

• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2012, 8, 411–412, doi:10.3762/bjoc.8.45

• biology in living systems. For this endeavour, chemical, biological and physical concepts and experiments have been equally important and equally challenging. In addition computer-aided methods, such as molecular dynamics studies of carbohydrates and glycoconjugates, have added valuable information about

Convergent synthesis of the tetrasaccharide repeating unit of the O-antigen of Shigella boydii type 9

• Abhishek Santra and
• Anup Kumar Misra

Beilstein J. Org. Chem. 2011, 7, 1182–1188, doi:10.3762/bjoc.7.137

• with the glycoconjugates derived from this tetrasaccharide repeating unit. The large quantity of the tetrasaccharide that is required for this purpose cannot be accessible from a natural source. Therefore, chemical synthesis is the only option for achieving this in large quantity. As a first step

• towards the preparation of glycoconjugates, we report herein a convergent chemical synthesis of the tetrasaccharide as its 4-methoxyphenyl glycoside 1 corresponding to the O-antigen of Shigella boydii type 9 using a [2 + 2] block glycosylation strategy (Figure 2). Results and Discussion The convergent

Synthesis of glycoconjugate fragments of mycobacterial phosphatidylinositol mannosides and lipomannan

• Benjamin Cao,
• Jonathan M. White and
• Spencer J. Williams

Beilstein J. Org. Chem. 2011, 7, 369–377, doi:10.3762/bjoc.7.47

• of a 3,4-butanediacetal-protected mannoside. The azidooctyl groups of these synthetic mannans were elaborated to fluorescent glycoconjugates and squaric ester derivatives useful for further conjugation studies. Keywords: fluorescently-labelled sugars; glycoconjugates; lipomannan; mycobacteria

• of a suite of fragments of the PIMs and LM, 1–4, and report their elaboration into glycoconjugates 5–10 for use as biological reagents to study PIM/LM/LAM biosynthesis and immunogenicity (Figure 1 and Figure 2). The azidooctyl aglycon has particular utility in this regard because of its (i

• chromatography or simple solvent partitioning. Incorporation of an azidooctyl group confers many of the same benefits as an octyl aglycon, with the additional advantage that the azido group may be elaborated into glycoconjugates. However, the synthesis of azidooctyl glycosides can be challenging as the use of

Carbasugar analogues of galactofuranosides: α-O-linked derivatives

• Jens Frigell and
• Ian Cumpstey

Beilstein J. Org. Chem. 2010, 6, 1127–1131, doi:10.3762/bjoc.6.129

• exemplify the method. Keywords: carbasugars; etherification; galactofuranose; glycomimetics; pseudodisaccharides; regioselective; Introduction Galactofuranose is found in nature as a component of glycoconjugates in many microorganisms [1][2]. Galactofuranosides with the α configuration are rather less

• -galactofuranose, which has an α configuration [1][2]. Modified, hydrolytically stable analogues of galactofuranosides could find application in the design and synthesis of potential inhibitors of the enzymes involved in the biosynthesis of galactofuranose-containing glycoconjugates. We have recently developed

Synthesis of 6-PEtN-α-D-GalpNAc-(1–>6)-β-D-Galp-(1–>4)-β-D-GlcpNAc-(1–>3)-β-D-Galp-(1–>4)-β-D-Glcp, a Haemophilus influenzae lipopolysacharide structure, and biotin and protein conjugates thereof

• Andreas Sundgren,
• Martina Lahmann and
• Stefan Oscarson

Beilstein J. Org. Chem. 2010, 6, 704–708, doi:10.3762/bjoc.6.80

• the title compound have been constructed to allow further use in biological experiments. Keywords: conjugate vaccines; glycoconjugates; Haemophilus influenzae; lacto-N-neotetraose; oligosaccharide synthesis; thioglycosides; Introduction Haemophilus influenzae are Gram-negative bacteria divided into

• synthesis of this structure and its conjugation to biotin and a carrier protein to form glycoconjugates that can be used in biological experiments to evaluate the immunological properties of the title structure. Results and Discussion The target structure is, as noted above, a substituted lacto-N

New amphiphilic glycopolymers by click functionalization of random copolymers – application to the colloidal stabilisation of polymer nanoparticles and their interaction with concanavalin A lectin

• Otman Otman,
• Paul Boullanger,
• Eric Drockenmuller and
• Thierry Hamaide

Beilstein J. Org. Chem. 2010, 6, No. 58, doi:10.3762/bjoc.6.58

• as glycoconjugates or as high molecular weight polymers, the actual “recognized” fractions are most often small oligosaccharides (3 to 10 carbohydrate units). Efficient binding has also been reported for monosaccharide ligands; for instance, galactose residues are targetable moieties for hepatocytes

Synthesis of glycosylated β³-homo-threonine conjugates for mucin-like glycopeptide antigen analogues

• Florian Karch and
• Anja Hoffmann-Röder

Beilstein J. Org. Chem. 2010, 6, No. 47, doi:10.3762/bjoc.6.47

• -glycosidically linked to the side chain of Fmoc-β3hThr-OH have been prepared by Arndt–Eistert homologation of the corresponding glycosylated α-amino acids 1a and 1b. The resulting β3hThr glycoconjugates are valuable antigen mimetics with potentially enhanced chemical and metabolic stability. They might serve as

(Pseudo)amide-linked oligosaccharide mimetics: molecular recognition and supramolecular properties

• José L. Jiménez Blanco,
• Fernando Ortega-Caballero,
• Carmen Ortiz Mellet and
• José M. García Fernández

Beilstein J. Org. Chem. 2010, 6, No. 20, doi:10.3762/bjoc.6.20

• centres (α or β), the presence of additional substituents such as sulfate or acyl groups and the overall degree of branching. The molecular diversity of oligosaccharide offers a valuable tool for drug discovery in the areas of biologically important oligosaccharides, glycoconjugates and molecular

Synthesis in the glycosciences

• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2010, 6, No. 16, doi:10.3762/bjoc.6.16

• Thisbe K. Lindhorst Otto Diels Institute of Organic Chemistry, Christiana Albertina University of Kiel, Otto-Hahn-Platz 3/4, 24098 Kiel, Germany 10.3762/bjoc.6.16 All cells are coated in carbohydrates and glycoconjugates. Today, after decades where sugars were regarded mainly as a means of energy