Synthesis of multiply fluorinated N-acetyl-D-glucosamine and D-galactosamine analogs via the corresponding deoxyfluorinated glucosazide and galactosazide phenyl thioglycosides

• Vojtěch Hamala,
• Lucie Červenková Šťastná,
• Martin Kurfiřt,
• Petra Cuřínová,
• Martin Dračínský and
• Jindřich Karban

Beilstein J. Org. Chem. 2021, 17, 1086–1095, doi:10.3762/bjoc.17.85

Unexpected loss of stereoselectivity in glycosylation reactions during the synthesis of chondroitin sulfate oligosaccharides

• Teresa Mena-Barragán,
• José L. de Paz and
• Pedro M. Nieto

Beilstein J. Org. Chem. 2019, 15, 137–144, doi:10.3762/bjoc.15.14

• -assisted synthesis of chondroitin sulfate (CS) oligosaccharides. Following this approach, a CS tetrasaccharide was prepared. However, in contrast to our previous results, a significant loss of β-selectivity was observed in [2 + 2] glycosylations involving N-trifluoroacetyl-protected D-galactosamine donors

• D-glucuronic acid (GlcA)-β(1→3)-N-acetyl-D-galactosamine (GalNAc)-β(1→4) disaccharides that may contain sulfate groups at different positions. This biopolymer plays a key role in biological events such as brain development and cancer [1]. The preparation of well-defined CS oligosaccharides is

• )-protected disaccharides 1 and 2 would be prepared from known building blocks 3 [35] and 4 [36] using D-glucurono-6,3-lactone and D-galactosamine hydrochloride as starting materials, respectively. The N-TFA group [37][38][39][40][41] is an adequeate choice for 2-amino protection of GalNAc moieties because it

Lectins of Mycobacterium tuberculosis – rarely studied proteins

• Katharina Kolbe,
• Sri Kumar Veleti,
• Norbert Reiling and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2019, 15, 1–15, doi:10.3762/bjoc.15.1

• host proteins and cell types, for example the invariant N-acetyl-D-glucosamine or N-acetyl-D-galactosamine residues that attach N- or O-glycans, respectively, to the peptide side chains, the large variety and possible permutations of “capping” residues (for example D-mannopyranosides, D

• acid (β-D-MurNAc/Gc) residues. The eukaryotic glycocalyx, composed of various glycolipids and glycoproteins, contains D-mannopyranosides (D-Manp), D-glucospyranosides (D-Glcp), D-galactopyranosides (D-Galp), L-fucopyranosides (L-Fucp), N-acetyl-D-glucosamine (D-GlcNAc), N-acetyl-D-galactosamine (D

Diosgenyl 2-amino-2-deoxy-β-D-galactopyranoside: synthesis, derivatives and antimicrobial activity

• Henryk Myszka,
• Patrycja Sokołowska,
• Agnieszka Cieślińska,
• Andrzej Nowacki,
• Maciej Jaśkiewicz,
• Wojciech Kamysz and
• Beata Liberek

Beilstein J. Org. Chem. 2017, 13, 2310–2315, doi:10.3762/bjoc.13.227

• the obtained compounds are active against Gram-positive bacteria and Candida type fungi. Keywords: antimicrobial activities; D-galactosamine; diosgenin; glycosylation; saponin; tetrachlorophthalimido derivatives; Introduction Saponins are steroid or triterpenoid glycosides found in various plants [1

• -β-D-galactopyranoside (4) (Scheme 1). This glycosyl donor was N-protected with the tetrachlorophthaloyl (TCP) group. The synthesis of 4 started from commercially available D-galactosamine hydrochloride which was first converted to the 2-N-tetrachlorophthaloyl derivative followed by peracetylation

• -ethyl derivative of D-glucosamine. Apart from N-ethyl also N-acetyl and 2-chloroethylureido derivatives exhibit activity against Gram-positive bacteria. The change of D-glucosamine into D-galactosamine in diosgenyl 2-amino-2-deoxy-β-D-glycopyranoside impairs the antimicrobial properties of its

Synthesis and in vitro cytotoxicity of acetylated 3-fluoro, 4-fluoro and 3,4-difluoro analogs of D-glucosamine and D-galactosamine

• Štěpán Horník,
• Lucie Červenková Šťastná,
• Petra Cuřínová,
• Jan Sýkora,
• Kateřina Káňová,
• Roman Hrstka,
• Ivana Císařová,
• Martin Dračínský and
• Jindřich Karban

Beilstein J. Org. Chem. 2016, 12, 750–759, doi:10.3762/bjoc.12.75

• Background: Derivatives of D-glucosamine and D-galactosamine represent an important family of the cell surface glycan components and their fluorinated analogs found use as metabolic inhibitors of complex glycan biosynthesis, or as probes for the study of protein–carbohydrate interactions. This work is

• focused on the synthesis of acetylated 3-deoxy-3-fluoro, 4-deoxy-4-fluoro and 3,4-dideoxy-3,4-difluoro analogs of D-glucosamine and D-galactosamine via 1,6-anhydrohexopyranose chemistry. Moreover, the cytotoxicity of the target compounds towards selected cancer cells is determined. Results: Introduction

• by fluoridolysis of 1,6:3,4-dianhydro-2-azido-β-D-galactopyranose with KHF2. The amino group was introduced and masked as an azide in the synthesis. The 1-O-deacetylated 3-fluoro and 4-fluoro analogs of acetylated D-galactosamine inhibited proliferation of the human prostate cancer cell line PC-3

Synthesis of the pentasaccharide repeating unit of the O-antigen of E. coli O117:K98:H4

• Pintu Kumar Mandal

Beilstein J. Org. Chem. 2014, 10, 2724–2728, doi:10.3762/bjoc.10.287

• kidneys [10][11]. The O-specific polysaccharide of E. coli O117:K98:H4 is a linear pentasaccharide repeating unit consisting of D-galactosamine, D-glucose, D-galactose, and L-rhamnose (Figure 1) [12]. Vaccination is the recent thrust in the drug discovery program to prevent bacterial infections. Several

• center; (d) glycosylation and removal of the p-methoxybenzyl (PMB) group in one-pot. Treatment of p-methoxyphenyl 4,6-O-benzylidene-2-deoxy-2-phthalimido-β-D-galactopyranoside (7) [24] (prepared from D-galactosamine hydrochloride in six steps) with acetic anhydride in pyridine followed by regioselective

Peptoids and polyamines going sweet: Modular synthesis of glycosylated peptoids and polyamines using click chemistry

• Daniel Fürniss,
• Timo Mack,
• Frank Hahn,
• Sidonie B. L. Vollrath,
• Katarzyna Koroniak,
• Ute Schepers and
• Stefan Bräse

Beilstein J. Org. Chem. 2013, 9, 56–63, doi:10.3762/bjoc.9.7

• synthesize also 1,3,4,6-tetra-O-acetyl-N-azidoacetyl-D-galactosamine (Ac4GalNAz = 2) and 1,3,4,6-tetra-O-acetyl-N-azidoacetyl-D-mannosamine (Ac4ManNAz = 3) with similar yields under these optimized conditions (see Supporting Information File 1). Click reaction on alkynylated polyamines and peptoids The

Antifreeze glycopeptide diastereomers

• Lilly Nagel,
• Carsten Budke,
• Axel Dreyer,
• Thomas Koop and
• Norbert Sewald

Beilstein J. Org. Chem. 2012, 8, 1657–1667, doi:10.3762/bjoc.8.190

• glycosylated with the disaccharide β-D-galactosyl-(1→3)-α-N-acetyl-D-galactosamine. In spite of the fact that all AFGPs found in arctic and antarctic fish share this structural homology, minor sequence variations occur, such as the replacement of alanine by proline [9][10] or the glycosylated threonine by

• residue and altered interaction pattern (e.g., by hydrogen bonds) between peptide and carbohydrate. According to the literature, model studies have provided indications that a carbohydrate such as N-acetyl-D-galactosamine influences the conformation by interactions such as hydrogen bonding and the