A bivalent glycopeptide to target two putative carbohydrate binding sites on FimH

• Thisbe K. Lindhorst,
• Kathrin Bruegge,
• Andreas Fuchs and
• Oliver Sperling

Beilstein J. Org. Chem. 2010, 6, 801–809, doi:10.3762/bjoc.6.90

• strategy [25] was applied to connect the monosaccharide and the trisaccharide part of the bivalent glycopeptide target structure 1 (Figure 2). Accordingly, retrosynthetic analysis of 1 leads to the 2-azidoethyl glycosides 2 and 5, with the azido group masking an amino function; two pentaglycine spacer

Preparation of aminoethyl glycosides for glycoconjugation

• Robert Šardzík,
• Gavin T. Noble,
• Martin J. Weissenborn,
• Andrew Martin,
• Simon J. Webb and
• Sabine L. Flitsch

Beilstein J. Org. Chem. 2010, 6, 699–703, doi:10.3762/bjoc.6.81

• aminoethyl glycosides of cell-surface carbohydrates, which are important intermediates for glycoarray synthesis, is described. A set of protocols was developed which provide these intermediates, in a short number of steps, from commercially available starting materials. Keywords: aminoethyl glycosides

• has been described in the literature [2][3][4][5][6][7][8][9][10][11][12], among which aminoalkyl glycosides have become the most popular, in particular the aminoethyl linker. This linker has been tested in a large number of arrays and appears to be biocompatible in array screening [2][3][7]. Given

• that aminoethyl glycosides are conveniently conjugated to surfaces containing activated carboxylates, they have become a useful generic anomeric functional group for glycoconjugation. The importance of this linker merits efforts into finding a robust synthetic method than can be used by scientists who

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

• instance, stable TACA mimics comprising C-glycosides [11][12][13][14], S-glycosides [15][16][17][18][19] and deoxyfluoro sugars [20] have been used to circumvent hydrolytic degradation by endogenous glycosidases. In principle, antigenicity of the artificial TACA derivatives should be enhanced by minor

(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

• involves the reaction of amine-glycosides with Steyemark-type gluco- and galactopyranosyl oxazolidinones [62][63]. Another example of natural disaccharide analogue containing a pseudoamide linkage is trehazolin 33 [64], which possesses a cyclic isourea functionality between the α-D-glucose and

Benzyne arylation of oxathiane glycosyl donors

• Martin A. Fascione and
• W. Bruce Turnbull

Beilstein J. Org. Chem. 2010, 6, No. 19, doi:10.3762/bjoc.6.19

• sulfur arylation, glycosylation of acetate ions proceeded with high levels of stereoselectivity to afford α-glycosyl acetates in a ‘one-pot’ reaction, even in the presence of alternative acceptor alcohols. Keywords: benzyne; 1,2-cis-glycosides; glycosyl acetates; oxathiane glycosyl donors

• , carbohydrate chemists must overcome the myriad challenges presented by their complex synthesis. The most important challenge is control over the stereoselectivity of reactions at the anomeric centre; in particular for the stereoselective synthesis of 1,2-cis-glycosides [9]. This area has been the subject of

• reported an elegant chiral auxiliary-based glycosylation protocol for the synthesis of 1,2-cis-α-glycosides [12]. Completely stereoselective glycosylation was achieved when a thiophenyl-containing chiral auxiliary was attached to O-2 of an imidate glycosyl donor 1 (Scheme 1a). Low temperature 1H NMR

Chemical synthesis using enzymatically generated building units for construction of the human milk pentasaccharides sialyllacto-N-tetraose and sialyllacto-N-neotetraose epimer

• Dirk Schmidt and
• Joachim Thiem

Beilstein J. Org. Chem. 2010, 6, No. 18, doi:10.3762/bjoc.6.18

• accessible selectively unprotected lactose acceptor glycosides the pentasaccharide structures sialyllacto-N-tetraose and the epimer of sialyllacto-N-neotetraose could be obtained in good yields, and subsequently transformed into their peracetylated derivatives for structure elucidation. Thus, a combination

Recognition properties of receptors consisting of imidazole and indole recognition units towards carbohydrates

• Monika Mazik and
• André Hartmann

Beilstein J. Org. Chem. 2010, 6, No. 9, doi:10.3762/bjoc.6.9

• glycosides. It has been shown that both hydrogen bonding and interactions of the carbohydrate CH units with the aromatic rings of the receptors contribute to the stabilization of the receptor–carbohydrate complexes. The molecular modeling calculations, synthesis and binding properties of 4 and 5 towards

• glycosides. The binding properties of 4 and 5 were studied on the base of 1H NMR spectroscopic titrations in CDCl3 and DMSO-d6/CDCl3 mixtures as well as binding studies in two-phase systems, such as dissolution of solid carbohydrates in apolar media. The imidazole-based receptor 4 was found to be a more

• -glucose [3], b) Amaranthus caudatus agglutinin with Galβ3GalNAc [1]. Structures of receptors 1–5. Structures of sugars investigated in this study. Structures of the recently described phenanthroline/aminopyridine-based receptors showing α- vs. β-anomer binding preferences in the recognition of glycosides

Dimerization of propargyl and homopropargyl 6-azido- 6-deoxy- glycosides upon 1,3-dipolar cycloaddition

• Nikolas Pietrzik,
• Daniel Schmollinger and
• Thomas Ziegler

Beilstein J. Org. Chem. 2008, 4, No. 30, doi:10.3762/bjoc.4.30

• -butynyl 2,3,4-tri-O-acetyl-6-azido-6-deoxy-glycopyranosides in the D-gluco, D-galacto and D-manno series afford the corresponding dimeric cycloaddition products. Keywords: click reaction; cyclodimerization; glycosides; triazoles; Introduction Our ongoing interest in constructing combinatorial libraries

• series of 1,2,3-triazole containing per-O-acetyl-glycosides which were prepared by copper-catalyzed 1,3-dipolar cycloaddition either between fully acetylated propargyl 1-thio-glycosides and t-butyl (S)-4-azido-3-fluorenylmethyloxycarbamido-butyrate or between Fmoc-L-Asp(OtBu)-propargyl amide and 2,3,4,6

• -tetra-O-acetyl-glycosyl azides and ethyl 2,3,4-tri-O-acetyl-6-azido-6-deoxy-1-thio-glycosides, respectively [12]. In order to increase the structural diversity of glycosyl amino acid building blocks containing 1,2,3-triazole spacers even more, we next looked at the possibility to use glycosides bearing

Solvent- controlled regioselective protection of allyl- 4,6-benzylidene glucopyranosides

• Kerry Ann Ness and
• Marie E. Migaud

Beilstein J. Org. Chem. 2007, 3, No. 26, doi:10.1186/1860-5397-3-26

• regioselectivity, alkylation and silylation reactions of other 4,6-benzylidene protected glycosides were carried out (Table 2, Table 3, Table 4). The reaction carried out with DMF as solvent gave the bis-protected galactosides when PMBCl was used and no reaction when the silylating reagents were used. In THF

Cimicifoetisides A and B, two cytotoxic cycloartane triterpenoid glycosides from the rhizomes of Cimicifuga foetida, inhibit proliferation of cancer cells

• Li-Rong Sun,
• Chen Qing,
• Yan-Li Zhang,
• Shu-Yu Jia,
• Zhong-Rong Li,
• Shen-Ji Pei,
• Ming-Hua Qiu,
• Michael L. Gross and
• Samuel X. Qiu

Beilstein J. Org. Chem. 2007, 3, No. 3, doi:10.1186/1860-5397-3-3

• 10.1186/1860-5397-3-3 Abstract Two new cycloartane-type triterpene glycosides, namely cimicifoetisides A (1) and B (2), along with seven known compounds cimigenol, 25-O-acetylcimigenol, cimigenol 3-O-β-D-xylopyranoside, 12β-hydroxycimigenol 3-O-β-D-xylopyranoside, cimigenol 3-O-α-L-arabinopyranoside, 25

• imported into Western markets. [5] In our continuing search for novel anti-cancer agents from natural products, we found that a methanol extract from the rhizomes of C. foetida exhibited considerable cytotoxicity to human cancer cell lines. To date, more than 30 triterpene glycosides have been isolated

• from C. foetida collected from different geographic regions. [6][7][8][9] In the present investigation on C. foetida collected from prefecture of Dali county in Yunnan province, Southern China, two novel glycosides, designated cimicifoetisides A (1) and B (2), containing a relatively uncommon acetyl

Study of thioglycosylation in ionic liquids

• Jianguo Zhang and
• Arthur Ragauskas

Beilstein J. Org. Chem. 2006, 2, No. 12, doi:10.1186/1860-5397-2-12

• thiomethyl glycosides could readily be activated with methyl trifluoromethane sulfonate, using 1-butyl-3-methylimidazolium tetrafluoroborate as a solvent. This green chemistry glycosylation strategy provided disaccharides with typical yields averaging 75%. The ionic liquid solvent could be readily reused for

• . reported that the glycosidations of glucopyranosyl fluorides with assorted alcohols employing an ionic liquid and a protic acid catalyst proceeded, under mild conditions, to afford the corresponding glycosides in 54–91% yields.[7] The stereoselectivity of the glycosidation was significantly affected by the

• ][9] These reactions typically provided over 70% yields of the corresponding glycosides or disaccharides. The intrinsic properties of the ionic liquids described above facilitate reaction work-up and recycling of the solvent. The purpose of this investigation was to examine the potential of employing

Methods for the synthesis of polyhydroxylated piperidines by diastereoselective dihydroxylation: Exploitation in the two-directional synthesis of aza-C-linked disaccharide derivatives

• Andrew Kennedy,
• Adam Nelson and
• Alexis Perry

Beilstein J. Org. Chem. 2005, 1, No. 2, doi:10.1186/1860-5397-1-2

• disaccharide mimetics are highly resistant to chemical and enzymatic hydolysis because a methylene group replaces the exo-oxygen of the glycosidic linkage, and the labile O/N acetal functionality is avoided. The conformation of aza-C-linked glycosides appears to be largely governed by 1,3-syn diaxial