Intramolecular glycosylation

• Xiao G. Jia and
• Alexei V. Demchenko

Beilstein J. Org. Chem. 2017, 13, 2028–2048, doi:10.3762/bjoc.13.201

• phthaloyl linkers in terms of stereoselectivity and yields. Thus, a tethered donor-central unit conjugate 53 was coupled with the BPA-conjugated glycosyl acceptor 54 using DCC/DMAP-mediated coupling reaction to obtain the templated conjugate of three monosaccharide units 55 in 82% yield. The selective

Enzymatic synthesis of glycosides: from natural O- and N-glycosides to rare C- and S-glycosides

• Jihen Ati,
• Pierre Lafite and
• Richard Daniellou

Beilstein J. Org. Chem. 2017, 13, 1857–1865, doi:10.3762/bjoc.13.180

• remains highly target-dependent and therefore a challenge in too many cases. Even so, glycochemists were very recently able to chemically synthesize the largest polysaccharide to date: a mycobacterial arabinogalactan of 92 monosaccharide units [5]. However, recent advances especially in the area of

• amino acid to mutate the acid/base is of crucial importance as it directly dictates the level of activity [66], but it cannot be predicted nor be a guarantee for success [67]. In general, the reported thiol acceptor is a monosaccharide or a substituted thiophenol (Figure 8). These engineered GHs were

Aqueous semisynthesis of C-glycoside glycamines from agarose

• Juliana C. Cunico Dallagnol,
• Alexandre Orsato,
• Diogo R. B. Ducatti,
• Miguel D. Noseda,
• Maria Eugênia R. Duarte and
• Alan G. Gonçalves

Beilstein J. Org. Chem. 2017, 13, 1222–1229, doi:10.3762/bjoc.13.121

• available, these polysaccharides are far little explored as sources of chemical platforms for drug development. The rare monosaccharide 3,6-anhydro-α-L-galactopyranose (AnGal), naturally present in the agarose structure, is a valuable scaffold since it is a highly functionalized and a chiral-rich monomer

• . This moiety is indeed presumed to play an important role in the bioactivity of agar-oligosaccharides [4][5][6]. As AnGal appears polymerized within the agarose backbone, a conceivable way to obtain it as a free monosaccharide would involve the cleavage of the glycosidic linkages of the polysaccharide

• -containing oligosaccharides from 1 by acid hydrolysis, it is important to notice that the 3,6-anhydrogalactosidic bonds are more acid labile than most of pyranoses. In this way, if AnGal is not produced as a free monosaccharide, it is found as the reducing terminal of the resulting oligosaccharides. Due to

Sugar-based micro/mesoporous hypercross-linked polymers with in situ embedded silver nanoparticles for catalytic reduction

• Qing Yin,
• Qi Chen,
• Li-Can Lu and
• Bao-Hang Han

Beilstein J. Org. Chem. 2017, 13, 1212–1221, doi:10.3762/bjoc.13.120

• derived from the monosaccharide has certain effects on the SSA and PSD of the prepared porous polymers, porosity tuning can be likely achieved with varying monomer molecular structures. Moreover, the aldehyde or ketone groups of the material provide the possibility for further modification and

Glycoscience@Synchrotron: Synchrotron radiation applied to structural glycoscience

• Serge Pérez and
• Daniele de Sanctis

Beilstein J. Org. Chem. 2017, 13, 1145–1167, doi:10.3762/bjoc.13.114

• on transport proteins that are responsible for uptake or release. To date, three main families of eukaryotic transporters have been identified GLUTs, SGLTs, and SWEETs – the most recently discovered sugar transport family, which is responsible for cellular export. In mammals, 14 monosaccharide

An eco-compatible strategy for the diversity-oriented synthesis of macrocycles exploiting carbohydrate-derived building blocks

• Sushil K. Maurya and
• Rohit Rana

Beilstein J. Org. Chem. 2017, 13, 1106–1118, doi:10.3762/bjoc.13.110

• with many functional groups found application in pharmaceuticals, agrochemicals, cosmetics and materials science [1][2][3][4]. Carbohydrate-embedded macrocycles represent an important class of macrocyclic compounds in which at least two bonds from a monosaccharide residue form a part of the macrocyclic

Glyco-gold nanoparticles: synthesis and applications

• Federica Compostella,
• Olimpia Pitirollo,
• Alessandro Silvestri and
• Laura Polito

Beilstein J. Org. Chem. 2017, 13, 1008–1021, doi:10.3762/bjoc.13.100

• (FRET). In the presence of the analyte (i.e., cholera toxin), galactose-AuNPs recognize the protein, avoiding the formation of QD complex and, consequently recovering the fluorescence. This method, although based on a monosaccharide, showed the impressive improvement obtained for using multivalent glyco

Total synthesis of TMG-chitotriomycin based on an automated electrochemical assembly of a disaccharide building block

• Yuta Isoda,
• Norihiko Sasaki,
• Kei Kitamura,
• Shuji Takahashi,
• Sujit Manmode,
• Naoko Takeda-Okuda,
• Jun-ichi Tamura,
• Toshiki Nokami and
• Toshiyuki Itoh

Beilstein J. Org. Chem. 2017, 13, 919–924, doi:10.3762/bjoc.13.93

• afforded TMG-chitotriomycin (1) in 21% yield (10 steps from disaccharide 5bβ) [31]. Conclusion In conclusion, we have achieved the stereoselective synthesis of TMG-chitotriomycin (1) based on the automated electrochemical assembly of disaccharide and monosaccharide building blocks. Thus-obtained

Fluorescent carbon dots from mono- and polysaccharides: synthesis, properties and applications

• Stephen Hill and
• M. Carmen Galan

Beilstein J. Org. Chem. 2017, 13, 675–693, doi:10.3762/bjoc.13.67

• Glucose-based fluorescent carbon dots Sustainable syntheses of CDs have driven researchers to find readily available, cheap and renewable carbon sources of which the monosaccharide glucose is an ideal candidate. Not only is glucose cheap and commercially available, but also has a low carbonisation

• glucose, this particular monosaccharide has been extensively used as an ideal carbon source for CD formation, under a range of experimental conditions. The microwave-assisted synthesis of FCDs from a glucose solution in the presence of poly(ethylene glycol)-200 (PEG-200) by Yang et al. is, to the best of

• improved materials with high QYs. Non-glucose monosaccharide-based fluorescent carbon dots In addition to glucose, different monosaccharides and polyols have also been utilised as carbon sources for the synthesis of FCD, although this approach is less common. The ability of glycerol to undergo dehydration

Total synthesis of a Streptococcus pneumoniae serotype 12F CPS repeating unit hexasaccharide

• Peter H. Seeberger,
• Claney L. Pereira and
• Subramanian Govindan

Beilstein J. Org. Chem. 2017, 13, 164–173, doi:10.3762/bjoc.13.19

• vaccines is the assembly of the trisaccharide β-D-GalpNAc-(1→4)-[α-D-Glcp-(1→3)]-β-D-ManpNAcA, in which the branching points are equipped with orthogonal protecting groups. A linear approach relying on the sequential assembly of monosaccharide building blocks proved superior to a convergent [3 + 3

• (Scheme 1, route B). Building block synthesis. The accessibility of differentially protected monosaccharide building blocks is a prerequisite for the successful total synthesis of any complex glycan. The synthesis of the mannosazide building block was the first challenge to be addressed. Installation of a

• Information File 1). Cleavage of the silyl ether by TBAF treatment of 15 afforded the β-mannosazide building block 18. Convergent [3 + 3] synthesis. Synthesis of the reducing-end trisaccharide 3 (Scheme 1) commenced with the assembly of the α-1→2 linked diglucoside 19 by union of the monosaccharide building

Silyl-protective groups influencing the reactivity and selectivity in glycosylations

• Mikael Bols and
• Christian Marcus Pedersen

Beilstein J. Org. Chem. 2017, 13, 93–105, doi:10.3762/bjoc.13.12

• monosaccharide thioglycosides were subjected to linking the 3 and 6-OH group together with this silyl ether. This forces the glycosyl-donor conformation to change into an axial-rich conformation and hence into a superarmed donor (Table 2) making it possible to glycosylate an armed glycosyl donor selectively

Synthesis of multi-lactose-appended β-cyclodextrin and its cholesterol-lowering effects in Niemann–Pick type C disease-like HepG2 cells

• Keiichi Motoyama,
• Rena Nishiyama,
• Yuki Maeda,
• Taishi Higashi,
• Yoichi Ishitsuka,
• Yuki Kondo,
• Tetsumi Irie,
• Takumi Era and
• Hidetoshi Arima

Beilstein J. Org. Chem. 2017, 13, 10–18, doi:10.3762/bjoc.13.2

• . Stokmaier et al. revealed that the binding affinity of galactose to ASGPR elevated 100–1000 fold from mono- to triantennary galactose structures, probably due to clustering effects [22]. The dissociation constant of monosaccharide with ASGPR was 10–4 M, whereas those of triantennary and tetraantennary

Orthogonal protection of saccharide polyols through solvent-free one-pot sequences based on regioselective silylations

• Serena Traboni,
• Emiliano Bedini and
• Alfonso Iadonisi

Beilstein J. Org. Chem. 2016, 12, 2748–2756, doi:10.3762/bjoc.12.271

• reaction under standard conditions [39][40]. As already observed for the synthesis of 2, the herein described conditions for regioselective TBDMS and TBDPS protections entail shorter reaction times than most of the reported protocols in the literature on monosaccharide polyols [14][15][16][17][18][20][41

Interactions between cyclodextrins and cellular components: Towards greener medical applications?

• Loïc Leclercq

Beilstein J. Org. Chem. 2016, 12, 2644–2662, doi:10.3762/bjoc.12.261

• , polysaccharides serve also as structural components: cellulose for plants and chitin for arthropods. Moreover, saccharides and their derivatives play key roles in the immune system, fertilization, blood clotting, information transfer, etc. For instance, the 5-carbon monosaccharide ribose forms the backbone of the

TMSBr-mediated solvent- and work-up-free synthesis of α-2-deoxyglycosides from glycals

• Mei-Yuan Hsu,
• Yi-Pei Liu,
• Sarah Lam,
• Su-Ching Lin and
• Cheng-Chung Wang

Beilstein J. Org. Chem. 2016, 12, 1758–1764, doi:10.3762/bjoc.12.164

• yields with moderate α-selectivity (α:β = 4:1). Surprisingly, in the glycosylation with secondary monosaccharide acceptor 24, α-disaccharide 37 (56%, Table 3, entry 13) was isolated as the sole product. For per-O-benzylated glucal 3, a higher yield of 38 (97%, Table 3, entry 14) was produced with good

• with moderate selectivity similar to the examples of the products of primary monosaccharide acceptors 22 and 23. Finally, the secondary monosaccharide acceptor 24 (Table 3, entry 27) also underwent complete α-selective glycosylation, producing α-disaccharide 50 (67%) as the only product. According to

• presence of 22 with a moderate yield and selectivity (50%, α:β = 4:1). When primary monosaccharide 23 was used as the acceptor, disaccharide 62 was provided in an excellent yield and selectivity (94%, α:β = 10:1, Table 4, entry 12). Additionally, a 60% yield of the α-only product 63 was observed

Automated glycan assembly of a S. pneumoniae serotype 3 CPS antigen

• Markus W. Weishaupt,
• Stefan Matthies,
• Mattan Hurevich,
• Claney L. Pereira,
• Heung Sik Hahm and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2016, 12, 1440–1446, doi:10.3762/bjoc.12.139

• -automation chemical modifications and the loss of product, we assembled pneumococcal serotype 3 CPS structures utilizing glucose and glucuronic acid monosaccharide building blocks and thus avoided late-stage oxidations. Results and Discussion Mindful of this strategic framework, glucuronic acid building

Elucidation of a masked repeating structure of the O-specific polysaccharide of the halotolerant soil bacteria Azospirillum halopraeferens Au4

• Elena N. Sigida,
• Yuliya P. Fedonenko,
• Alexander S. Shashkov,
• Nikolay P. Arbatsky,
• Evelina L. Zdorovenko,
• Svetlana A. Konnova,
• Vladimir V. Ignatov and
• Yuriy A. Knirel

Beilstein J. Org. Chem. 2016, 12, 636–642, doi:10.3762/bjoc.12.62

• , including survival of bacteria under salinity [10][11][12][13]. Preliminary chemical data on the LPS of A. halopraeferens type strain Au4, including fatty acid and monosaccharide composition, have been reported [14]. As biological functions of the LPS are expected to depend on their structures, this study

• downfield to δ 78.9–79.0 as compared with its positions in the non-substituted α-Fuc at δ 70.6 [19]. The 13C NMR chemical shifts for C-2–C-6 of Rha in 1 were close to those of the non-substituted monosaccharide [19], whereas in 2, the signal for C-2 of Rha was observed in a low field at δ 81.4 evidently due

Art, auto-mechanics, and supramolecular chemistry. A merging of hobbies and career

• Eric V. Anslyn

Beilstein J. Org. Chem. 2016, 12, 362–376, doi:10.3762/bjoc.12.40

• group created some of the earliest reported monosaccharide receptors (4) that exploited hydrogen bonding based recognition in chloroform [39][40]. The receptor designs from Hamilton (5) [41] and Thummel (6) [42] at around the same period of time clearly influenced my own designs. This was approximately

Cholesterol lowering effects of mono-lactose-appended β-cyclodextrin in Niemann–Pick type C disease-like HepG2 cells

• Keiichi Motoyama,
• Yumi Hirai,
• Rena Nishiyama,
• Yuki Maeda,
• Taishi Higashi,
• Yoichi Ishitsuka,
• Yuki Kondo,
• Tetsumi Irie,
• Takumi Era and
• Hidetoshi Arima

Beilstein J. Org. Chem. 2015, 11, 2079–2086, doi:10.3762/bjoc.11.224

• galactose with ASGPR enhanced 100–1000 fold from mono- to triantennary galactose structure due to cluster effects [29]. Stokmaier et al. reported that the dissociation constant of monosaccharide with ASGPR was 10−4 M, while those of triantennary and tetraantennary with ASGPR were 5 × 10−9 M and 9 × 10−9 M

DNA display of glycoconjugates to emulate oligomeric interactions of glycans

• Alexandre Novoa and
• Nicolas Winssinger

Beilstein J. Org. Chem. 2015, 11, 707–719, doi:10.3762/bjoc.11.81

• conjugate, the same group reported the synthesis of phosphoramidite derivatized with an acetyl-protected monosaccharide 3 and its incorporation into DNA to access well-defined DNA conjugates 4 (Scheme 2). Cleavage of the acetate groups occurs upon ammonia treatment for DNA cleavage/deprotection [19][20][21

Automated solid-phase synthesis of oligosaccharides containing sialic acids

• Chian-Hui Lai,
• Heung Sik Hahm,
• Chien-Fu Liang and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2015, 11, 617–621, doi:10.3762/bjoc.11.69

• glycopeptides [6], glycosaminoglycans [7][8][9], and chains as long as 30-mers [10]. Key to automated assembly is the identification of reliable monosaccharide building blocks to construct particular linkages. To date, α-(2,3)- and α-(2,6)-sialylated glycans have been accessible by automation only via

• automated method for chemical sialylation. Monosaccharide building blocks 4, 5 [14], 6, 7 [21], 8, 9 [21], and 10 [5] were employed for these syntheses. Merrifield polystyrene resin equipped with a photocleavable linker, 11, was placed in the reaction chamber of the automated synthesizer and the coupling

Synthesis of a hexasaccharide partial sequence of hyaluronan for click chemistry and more

• Marina Bantzi,
• Stephan Rigol and
• Athanassios Giannis

Beilstein J. Org. Chem. 2015, 11, 604–607, doi:10.3762/bjoc.11.67

• ][23] was linked with glycosyl acceptor 2 [24][25] using TMSOTf as promoter to obtain disaccharide 4 in 90% yield. Likewise, reaction of glycosyl donor 1 with monosaccharide 3 [26] and subsequent O-TBS group cleavage with Olah's reagent [27], afforded disaccharide 5 in 86% yield. Thence, both

Synthesis and biological evaluation of a novel MUC1 glycopeptide conjugate vaccine candidate comprising a 4’-deoxy-4’-fluoro-Thomsen–Friedenreich epitope

• Manuel Johannes,
• Maximilian Reindl,
• Bastian Gerlitzki,
• Edgar Schmitt and
• Anja Hoffmann-Röder

Beilstein J. Org. Chem. 2015, 11, 155–161, doi:10.3762/bjoc.11.15

• spectrometry, the amount of enzymatic digestion of the disaccharides 12 and 13, which in both cases would yield the corresponding Tn monosaccharide 15 was determined over time (Figure 1 and Supporting Information File 1). Whereas half of the native TF derivative 13 was digested in approximately 3 h, the 4’F-TF

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

• been synthesized using a combination of sequential glycosylations and [3 + 2] block synthetic strategy from the suitably protected monosaccharide intermediates. Thioglycosides and glycosyl trichloroacetimidate derivatives have been used as glycosyl donors in the glycosylations. Keywords: Escherichia

• pentasaccharide 1 has been synthesized as its 3-aminopropyl glycoside using a combination of sequential and [3 + 2] block glycosylation strategy. A trisaccharide acceptor 11 and a disaccharide trichloroacetimidate donor 14 were synthesized from the appropriately protected monosaccharide intermediates 2 [20], 3

Galactan synthesis in a single step via oligomerization of monosaccharides

• Marius Dräger and
• Amit Basu

Beilstein J. Org. Chem. 2014, 10, 2658–2663, doi:10.3762/bjoc.10.279

• fluoride with lanthanum perchlorate in the presence of an initiator alcohol. The product oligosaccharides were readily chromatographically separable. This oligomerization was used to synthesize a pentagalactan in a single step from monosaccharide building blocks in reasonable overall yields. Keywords

• ]. Self-reaction of the donor, usually by cyclization, was a consistently significant side-reaction and even the source of the major product in several instances. To the best of our knowledge, there have not been any reports of monosaccharide oligmerization to provide stereochemically pure, discrete and

• our surprise, the reaction provided both the desired monosaccharide 41a as well as significant amounts of the disaccharide 42a and trisaccharide 43a (entry 1, Table 1) [20]. We surmised that the fluoride ion derived from the activated glycosyl donor was responsible for desilylating 1 during the course