Monitoring carbohydrate 3D structure quality with the Privateer database

• Jordan S. Dialpuri,
• Haroldas Bagdonas,
• Lucy C. Schofield,
• Phuong Thao Pham,
• Lou Holland and
• Jon Agirre

Beilstein J. Org. Chem. 2024, 20, 931–939, doi:10.3762/bjoc.20.83

• calculated by Privateer and, most importantly, the diagnostic provided by Privateer (Figure 4). A ‘yes’ diagnostic indicates the conformation is correct for the glycosylation type (e.g., 4C1 for GlcNAc in an N-glycan, 1C4 for mannose in a C-glycan), has the correct anomer, and has an acceptable fit to

Introduction of a human- and keyboard-friendly N-glycan nomenclature

• Friedrich Altmann,
• Johannes Helm,
• Martin Pabst and
• Johannes Stadlmann

Beilstein J. Org. Chem. 2024, 20, 607–620, doi:10.3762/bjoc.20.53

• , aspects of how to name structures with different types of fucosylation, sialylation or antennary branching, bisecting GlcNAc, GalNAc, oligomannosidic structures and more will be discussed. Discussion The beginnings and the basics In the 90ties during a guest visit in our lab, Prof. Harry Schachter from

• of glycoproteins solidified our faith in a rather universal applicability of this system [26][27]. But now, back to the meaning of “GnGn”. Gn stands for GlcNAc and the two Gn-s symbolize the two terminal residues of a biantennary N-glycan (Figure 2). The GlcNAcs are attached to the common core

• pentasaccharide. No further definitions are required as the residues preceding the GlcNAcs are unambiguously determined by the biosynthetic pathway of N-glycans. Action of hexosaminidases would generate two isomers with just one GlcNAc and a terminal mannose residue. By defining the reading direction, we can

Elucidating the glycan-binding specificity and structure of Cucumis melo agglutinin, a new R-type lectin

• Jon Lundstrøm,
• Emilie Gillon,
• Valérie Chazalet,
• Nicole Kerekes,
• Antonio Di Maio,
• Ten Feizi,
• Yan Liu,
• Annabelle Varrot and
• Daniel Bojar

Beilstein J. Org. Chem. 2024, 20, 306–320, doi:10.3762/bjoc.20.31

• , there are still significant gaps in our understanding. Further, in general, few melon lectins have been studied in detail. Some reports indicate the presence of chitooligosaccharide-binding (i.e., β1-4 GlcNAc oligomers) lectins from phloem exudates of melons [16][17], as well as R-type lectins in bitter

• actively and strongly prefers C2-substituted Gal, while RCA1 does not even tolerate these substitutions. Interestingly, we also find that fucosylation of the GlcNAc residue (as in Lewis antigen motifs) completely abrogates CMA1 binding (Figure S1, Supporting Information File 2), despite the presence of

• approximately 42 °C (Figure 3b). Then, we tested the binding of CMA1 to GlcNAc, GalNAc, and H type 2 blood group antigen (BGHT2; Fucα1-2Galβ1-4GlcNAcβ1-3Gal; Figure 3c). This resulted in clear melting points shifts for both GalNAc and BGHT2 to up to 50 °C, yet importantly not for GlcNAc, demonstrating both

Optimizations of lipid II synthesis: an essential glycolipid precursor in bacterial cell wall synthesis and a validated antibiotic target

• Milandip Karak,
• Cian R. Cloonan,
• Brad R. Baker,
• Rachel V. K. Cochrane and
• Stephen A. Cochrane

Beilstein J. Org. Chem. 2024, 20, 220–227, doi:10.3762/bjoc.20.22

• , a critical step in the formation of the central disaccharide unit (GlcNAc-MurNAc), was optimized. This was achieved by employing the use of glycosyl donors with diverse leaving groups. The key advantage of this approach lies in its adaptability, allowing for the generation of a wide array of

• -phosphoryl GlcNAc-MurNAc-pentapeptide 7, based on established protocols with minor adjustments was completed (Scheme 1) [10][11]. After the successful glycosylation reaction, disaccharide 3a, protected with C2-Troc and C6-benzyl groups, was efficiently deprotected under acidic conditions using ZnCl2/Zn

• , leading to the formation of the α-phosphoryl GlcNAc-MurNAc-monopeptide derivative. Subsequently, coupling this intermediate with tetrapeptide, TFA·H-ʟ-Ala-γ-ᴅ-Glu(OMe)-ʟ-Lys(COCF3)-ᴅ-Ala-ᴅ-Ala-OMe under mild conditions resulted in the synthesis of dibenzyl α-phosphoryl GlcNAc-MurNAc-pentapeptide 7 (see

Synthesis of the 3’-O-sulfated TF antigen with a TEG-N₃ linker for glycodendrimersomes preparation to study lectin binding

• Mark Reihill,
• Hanyue Ma,
• Dennis Bengtsson and
• Stefan Oscarson

Beilstein J. Org. Chem. 2024, 20, 173–180, doi:10.3762/bjoc.20.17

• (β-ᴅ-GalNAc-(1→4)-β-ᴅ-GlcNAc), which have then been used for production of the glycodenrimersomes and interaction studies with various galectins [1][2]. In the continuation of this collaboration, to investigate the binding of siglec-1 and the chimera of 3’-SuTF-binding siglecs and TF-binding galectin

Studying specificity in protein–glycosaminoglycan recognition with umbrella sampling

• Mateusz Marcisz,
• Sebastian Anila,
• Margrethe Gaardløs,
• Martin Zacharias and
• Sergey A. Samsonov

Beilstein J. Org. Chem. 2023, 19, 1933–1946, doi:10.3762/bjoc.19.144

• polysaccharides, with repeating disaccharide units comprised of a hexuronic acid (or galactose in keratan sulfate) and a hexosamine (N-acetylglycosamide, GlcNAc or N-acetylgalactososamide, GalNAc) throughout a regular alternation of 1→4 and 1→3-glycosidic linkages [1][2][3]. GAGs are mainly located on the cell

GlAIcomics: a deep neural network classifier for spectroscopy-augmented mass spectrometric glycans data

• Thomas Barillot,
• Baptiste Schindler,
• Baptiste Moge,
• Elisa Fadda,
• Franck Lépine and
• Isabelle Compagnon

Beilstein J. Org. Chem. 2023, 19, 1825–1831, doi:10.3762/bjoc.19.134

• vibrational resonances as a function of their frequency in the mid-IR range. After measuring its mass and its IR fingerprint, an unknown analyte (Figure 1a) is readily identified as "GlcNAc" (for N-acetylglucosamine) by comparison with the reference IR spectra of several candidates of identical mass (Figure

• ion trap mass analyzer. The following monosaccharides were analyzed: three stereoisomers of hexosamine of chemical formula C6H13NO5, namely glucosamine (GlcN), galactosamine (GalN), mannosamine (ManN); and N-acetyl glucosamine (GlcNAc, chemical formula C8H15NO6). One typical spectrum of each of the

• GlcNAc with 95% probability in average but for 10 inferences out of 200 (the lowest 5% percentile) the prediction probability is below 60%. In this example, by thresholding on the interpercentile range below 0.35 for the most likely prediction of each spectrum one can obtain a precision of 100%. Most

Shift of the reaction equilibrium at high pressure in the continuous synthesis of neuraminic acid

• Jannis A. Reich,
• Miriam Aßmann,
• Kristin Hölting,
• Paul Bubenheim,
• Jürgen Kuballa and
• Andreas Liese

Beilstein J. Org. Chem. 2022, 18, 567–579, doi:10.3762/bjoc.18.59

• the position of the reaction equilibrium. By this, equilibrium conversion, selectivity, and yield were increased from 57.9% to 63.9%, 81.9% to 84.7%, and 47.5% to 54.1%, respectively. This indicates a reduction in molar volume from N-acetyl-ᴅ-glucosamine (GlcNAc) and pyruvate (Pyr) to Neu5Ac. In

• for the aldolase from 108 to 42 mM and 91 to 37 mM, respectively. Keywords: aldolase; continuous fixed-bed reactor; enzyme; epimerase; GlcNAc; high pressure; immobilization; ManNAc; Neu5Ac; pyruvate; Introduction In times of a pandemic, the importance of substances to enhance the human immune system

• Figure 13. Since this reaction step is a two-to-one-reaction, a reduction in molar volume was expected, resulting in a positive influence of pressure (principle of Le Chatelier). The change in volume was calculated as −16.0 ± 1.2 mL/mol. Both immobilisates were added into one reactor and GlcNAc and Pyr

Progress and challenges in the synthesis of sequence controlled polysaccharides

• Giulio Fittolani,
• Theodore Tyrikos-Ergas,
• Denisa Vargová,
• Manishkumar A. Chaube and
• Martina Delbianco

Beilstein J. Org. Chem. 2021, 17, 1981–2025, doi:10.3762/bjoc.17.129

• chitosan Chitin is a linear polysaccharide composed of β(1–4)-linked 2-acetamido-2-deoxy-ᴅ-glucopyranose (GlcNAc) repeating units, which mainly exists in the exoskeleton of crustaceans and insects, as well as in the cell-wall of fungi [209][210]. Chitosan, its partially N-deacetylated analogue, has vast

• tuning of the DP and fraction of acetylation (FA). Chitooligosaccharides (COS: β(1–4)-linked oligomers of GlcNAc and/or GlcN) have gained popularity due to their exceptional antimicrobial, antitumor, and immune modulatory activities [29][213][214][215][216][217]. Methods to obtain well-defined COS with

A systems-based framework to computationally describe putative transcription factors and signaling pathways regulating glycan biosynthesis

• Theodore Groth,
• Rudiyanto Gunawan and
• Sriram Neelamegham

Beilstein J. Org. Chem. 2021, 17, 1712–1724, doi:10.3762/bjoc.17.119

• the addition of GlcNAc to processed N-linked glycan structures. These include all the MGAT enzymes. 7) GalNAc-type O-glycans: O-linked glycans are attached to serine (Ser) or threonine (Thr) on peptides, where GalNAc is the root carbohydrate. This is mediated by a family of about 20 Golgi-resident

• polypeptide N-acetylgalactosaminyltransferases (ppGalNAcTs or GALNTs). Core 1 structures result from the attachment of β1-3 linked galactose to the core GalNAc using C1GALT1 and the corresponding chaperone C1GALT1C1. Core 2 structures then form upon addition of β1-6-linked GlcNAc by GCNT1. Modifications of

• adds glucuronic acid to the terminal galactose. Also involved in the formation of this core is FAM20B, a kinase that 2-O-phosphorylates xylose. At this point, the addition of GalNAc to GlcA by CSGALNACT1 and 2 results in the initiation of chondroitin sulfate chains. The attachment of GlcNAc by EXTL3 to

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

• ]. Unprotected multiply-deoxyfluorinated N-acetyl-ᴅ-glucosamine (GlcNAc) and N-acetyl-ᴅ-galactosamine (GalNAc) have not yet been described except for a 4,6-difluoro-GalNAc analog [22], although GlcNAc is the most abundant monosaccharide component of mammalian glycans [23], and GalNAc occurs in important glycan

• structures including the TN and T antigen and their sialylated forms [24]. A complete series of O-protected monofluorinated [22][25][26][27][28][29][30][31][32] and several difluorinated [22][26][33][34] GlcNAc/GalNAc analogs have been prepared. Some acylated mono- and difluorinated analogs have potential in

• biomedical applications due to their ability to inhibit the glycan and glycosaminoglycan biosynthesis [34][35][36][37]. The fluorine substituent has typically been introduced into these GlcNAc and GalNAc analogues using nucleophilic fluorination. The primary position (C6 hydroxy group) was fluorinated by

Simulating the enzymes of ganglioside biosynthesis with Glycologue

• Andrew G. McDonald and
• Gavin P. Davey

Beilstein J. Org. Chem. 2021, 17, 739–748, doi:10.3762/bjoc.17.64

• , sialylation, galactosylation, and GlcNAc-ylation events among the different knockouts, and with that of the full network in Figure 4, reveals that the most pronounced effects on ganglioside complexity occur with enzyme activities 1, 3, and 7, which result in fewer than 10 reactions each. That any structures

A consensus-based and readable extension of Linear Code for Reaction Rules (LiCoRR)

• Benjamin P. Kellman,
• Yujie Zhang,
• Emma Logomasini,
• Eric Meinhardt,
• Karla P. Godinez-Macias,
• Austin W. T. Chiang,
• James T. Sorrentino,
• Chenguang Liang,
• Bokan Bao,
• Yusen Zhou,
• Sachiko Akase,
• Isami Sogabe,
• Thukaa Kouka,
• Elizabeth A. Winzeler,
• Iain B. H. Wilson,
• Matthew P. Campbell,
• Sriram Neelamegham,
• Frederick J. Krambeck,
• Kiyoko F. Aoki-Kinoshita and
• Nathan E. Lewis

Beilstein J. Org. Chem. 2020, 16, 2645–2662, doi:10.3762/bjoc.16.215

• monosaccharide listed by SNFG (Figure 2D). Figure 2D shows some of these non-trivial paths (e.g., beyond GlcNac; G → GN or G[2N]) from Table 4 monosaccharides, to all listed SFNG monosaccharides via modifications from Table 5. We further provide a full network (Table S6, Supporting Information File 1) to

• )Mb4. Here the “|” uncertainty operator is used to allow for the possible presence of a bisecting GlcNAc on the root mannose: Ma3(GNb4)(…Ma6)Mb4. The “*” indicates the site of the enzyme action. Possible branch “|” – As discussed, parsing a linear glycan from left to right, we can encounter matched

• possible modification site. For example, “A$GN” represents a GlcNAc connected to a galactose that might be modified. The modification can be specified (e.g., phosphorylation on the 2nd carbon) in the typical way, with square brackets “A$[2P]GN”. Recommendation 9 – “Branching index.” In LiCoRR we have

Leveraging glycomics data in glycoprotein 3D structure validation with Privateer

• Haroldas Bagdonas,
• Daniel Ungar and
• Jon Agirre

Beilstein J. Org. Chem. 2020, 16, 2523–2533, doi:10.3762/bjoc.16.204

• containing glycans that were previously unreported and inconsistent with glycan biosynthetic pathways. In particular, the model contained oligosaccharide chains with Man-(1→3)-GlcNAc and GlcNAc-(1→3)-GlcNAc linkages, β-galactosyl motifs capping oligomannose-type glycans and hybrid-type glycans containing

• terminal Man-(1→3)-GlcNAc [14]. Moreover, the proposed model contained systematic errors in the anomer annotations and carbohydrate stereochemistry. To this day, there is still no experimental evidence reported for these types of linkages and capping in an identical context. The new version of Privateer

How and why plants and human N-glycans are different: Insight from molecular dynamics into the “glycoblocks” architecture of complex carbohydrates

• Carl A. Fogarty,
• Aoife M. Harbison,
• Amy R. Dugdale and
• Elisa Fadda

Beilstein J. Org. Chem. 2020, 16, 2046–2056, doi:10.3762/bjoc.16.171

• similar to the one of higher species [25], carrying the distinctive trimannose core (Man3), which can be further functionalised with β(1-2)-linked GlcNAc residues on the arms. As a trademark feature, shown in Figure 1, plants N-glycans can also have a β(1-2)-Xyl linked to the central mannose and core α(1

• GlcNAc and results in the occurrence of Lewis A (LeA) instead of Lewis X (LeX) terminal motifs on the arms [23][26]. In a previous study, we characterized through extensive sampling the structure and dynamics of complex biantennary N-glycans commonly found in the human IgGs Fc region [24]. The results of

• % in Man3, to 52% in (F)A2, (F)A2[3]G1, and (F)A2[3]G1S1, where the (F) indicates the presence or absence of α(1-6) core fucosylation, to 24% in all structures with (1-6) arm terminating with Gal-β(1-4)-GlcNAc or Sia-α(2-6)-Gal-β(1-4)-GlcNAc, irrespective of the functionalization of the (1-3) arm [24

Synthesis, docking study and biological evaluation of ᴅ-fructofuranosyl and ᴅ-tagatofuranosyl sulfones as potential inhibitors of the mycobacterial galactan synthesis targeting the galactofuranosyltransferase GlfT2

• Marek Baráth,
• Jana Jakubčinová,
• Zuzana Konyariková,
• Stanislav Kozmon,
• Katarína Mikušová and
• Maroš Bella

Beilstein J. Org. Chem. 2020, 16, 1853–1862, doi:10.3762/bjoc.16.152

• decaprenyl-P-P-GlcNAc-Rha, (glycolipid 2, GL2), which serves as a lipid carrier for arabinogalactan polymerization [7][8]. The latter enzyme, GlfT2, extends the product of GlfT1-catalyzed reaction, decaprenyl-P-P-GlcNAc-Rha-Galf2 (glycolipid 4, GL4), producing the lipid-linked galactan polymer [8]. Both

• -up of lipid-linked galactan precursors. The crude enzymes used in the assay allow for in situ synthesis of the acceptor for galactan polymerization, decaprenyl-P-P-GlcNAc-Rha (GL2), from endogenous decaprenyl phosphate and sugar nucleotides UDP-GlcNAc and TDP-Rha supplied in the reaction mixture

• employed in the synthesis of its acceptor substrate, decaprenyl-P-P-GlcNAc-Rha-Galf2 (GL4). Based on the previous experimental data, which established Km values for GlfT2 250 or 380 µM at 37 °C [10][18][19], we tested the whole set of target compounds at a concentration of 500 µM. TLC analysis of the lower

Design, synthesis and biological evaluation of immunostimulating mannosylated desmuramyl peptides

• Rosana Ribić,
• Ranko Stojković,
• Lidija Milković,
• Mariastefania Antica,
• Marko Cigler and
• Srđanka Tomić

Beilstein J. Org. Chem. 2019, 15, 1805–1814, doi:10.3762/bjoc.15.174

• of the peptidoglycan monomer (PGM, Figure 1) which is used in this work. PGM is a well-defined and characterized disaccharide pentapeptide, β-ᴅ-GlcNAc-(1→4)-ᴅ-MurNAc-ʟ-Ala-ᴅ-isoGln-mesoDAP(εNH2)-ᴅ-Ala-ᴅ-Ala, originating from Brevibacterium divaricatum [8][9]. Peptidoglycans activate macrophages via

Towards the preparation of synthetic outer membrane vesicle models with micromolar affinity to wheat germ agglutinin using a dialkyl thioglycoside

• Dimitri Fayolle,
• Nathalie Berthet,
• Bastien Doumeche,
• Olivier Renaudet,
• Peter Strazewski and
• Michele Fiore

Beilstein J. Org. Chem. 2019, 15, 937–946, doi:10.3762/bjoc.15.90

• was measured by competitive enzyme-linked lectin assays. One of the synthetic compounds presenting two GlcNAc units showed the highest inhibitory effect of this study with an IC50 of 11 µM corresponding to a 3182-fold improvement compared to GlcNAc. These synthetic molecules were used to produce giant

• -glycosylated compounds were observed. Preparation of vesicles upon hydration of a thin film of phospholipids and glycolipids Once synthesized, the compounds 5 and 8 bearing GlcNAc residues were used to produce giant vesicles (GVs) upon hydration with PBS (pH 7.4) by modifying reported procedures [28][29][30

• horseradish peroxidase-labelled (WGA-HRP) to a GlcNAc-polyacrylamide conjugate following the procedure described in Figure 4. WGA is a homodimer in which each monomer is organized into four domains (A–D) containing adjacent “primary” (B and C) and “secondary” (A and D) domains binding sites with different

Cyclopropene derivatives of aminosugars for metabolic glycoengineering

• Jessica Hassenrück and
• Valentin Wittmann

Beilstein J. Org. Chem. 2019, 15, 584–601, doi:10.3762/bjoc.15.54

• of the staining intensity on the cell surface. Are Ac4GlcNCyoc and Ac4GlcNCp converted into sialic acids during MGE? It is well established that carbohydrate derivatives can be interconverted into each other by epimerases. For example, both GlcNAc and UDP-GlcNAc can be converted to ManNAc [37][38

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

• : filamentous hemagglutinin; L-Fucp: L-fucopyranoside; D-Galf: D-galactofuranoside; D-Galp: D-galactopyranoside; D-GlcNAc: N-acetyl-D-glucosamine; D-Glcp: D-glucopyranoside; HBHA: heparin-binding hemagglutinin; KDO: 3-deoxy-D-manno-octulosonic acid; LAM: lipoarabinomannan; LM: lipomannan; LPS

• -monomycolate (TMM), are α-D-mannopyranosides (α-D-Manp), α-D-glucopyranosides (α-D-Glcp), α-D-galactofuranosides (α-D-Galf), α-D-arabinofuranosides (α-D-Araf), α-L-rhamnopyranosides (α-L-Rhap), N-acetyl-α-D-glucosamine (α-D-GlcNAc), N-acetyl-β-D-glucosamine (β-D-GlcNAc), and N-acetyl- or N-glycolyl-β-D-muramic

• 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

Anomeric modification of carbohydrates using the Mitsunobu reaction

• Julia Hain,
• Patrick Rollin,
• Werner Klaffke and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2018, 14, 1619–1636, doi:10.3762/bjoc.14.138

• native D-glucose, D-GlcNAc or D-maltose resulted in regioselective esterification of the primary OH group, leaving all other hydroxy groups including the anomeric OH unmodified [38]. On the other hand, other authors have reported that the anomeric position can be selectively modified in a Mitsunobu

A stereoselective and flexible synthesis to access both enantiomers of N-acetylgalactosamine and peracetylated N-acetylidosamine

• Bettina Riedl and
• Walther Schmid

Beilstein J. Org. Chem. 2018, 14, 856–860, doi:10.3762/bjoc.14.71

• relationship studies. Several strategies for the synthesis of 2-amino sugars have been published so far. In one exemplary straightforward approach, GalNAc was prepared by inverting the stereogenic center at the C-4 position of N-acetylglucosamine (GlcNAc) [10]. However, the necessity of using a 2-amino sugar

Synthetic and semi-synthetic approaches to unprotected N-glycan oxazolines

• Antony J. Fairbanks

Beilstein J. Org. Chem. 2018, 14, 416–429, doi:10.3762/bjoc.14.30

• synthetic approaches reported, the majority rely on the fabrication (either by total synthesis, or semi-synthesis from locust bean gum) of a key Manβ(1–4)GlcNAc disaccharide, which can then be elaborated at the 3- and 6-positions of the mannose unit using standard glycosylation chemistry. Early approaches

• ] (ENGases, EC 3.2.1.96), a class of enzyme which specifically cleave between the innermost two GlcNAc residues of N-glycans attached to N-linked glycoproteins, all operate via a two-step mechanism involving neighbouring group participation of the 2-acetamide group and an oxazoline as a high energy

• ., those derived from GlcNAc), the corresponding manno [10][11] and galacto-configured [12] compounds have also been made and studied. Although the first generation of these oxazoline donors [13][14] proved to be rather unreactive, and found only limited applications [15][16][17][18], the addition of three

Aminosugar-based immunomodulator lipid A: synthetic approaches

• Alla Zamyatina

Beilstein J. Org. Chem. 2018, 14, 25–53, doi:10.3762/bjoc.14.3

Recent applications of click chemistry for the functionalization of gold nanoparticles and their conversion to glyco-gold nanoparticles

• Vivek Poonthiyil,
• Thisbe K. Lindhorst,
• Vladimir B. Golovko and
• Antony J. Fairbanks

Beilstein J. Org. Chem. 2018, 14, 11–24, doi:10.3762/bjoc.14.2

• been reported by Baranov et al. [77]. GlcNAc azide 34 was synthesized following the reported procedure (Supporting Information File 1) [76], and CuAAC of azide 34 and the AAT-AuNPs was attempted (Supporting Information File 1). Initially, only 1.5 mol % of CuSO4·5H2O (with respect to the ligands on the

• obtained. In further experiments the CuAAC was attempted using a solution of purified GlcNAc azide 34. Water and THF were used as the solvent in a 1:1 ratio to be in line with the conditions reported by Boisselier et al. [62]. However, even with these conditions precipitation of the particles could not be

• 88: Synthetic protocols and spectral and TEM characterisation for ATT 33 (Scheme 11), ATT-AuNPs (Scheme 11), GlcNAc azide 34, and click reaction of ATT-AuNPs.