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

• -glucosides were formed in their corresponding products 33 (71%, 5:1, Table 3, entry 9) and 34 (79%, 4:1, Table 3, entry 10). For the use of monosaccharides as acceptors, primary monosaccharides 22 and 23 gave disaccharides 35 (80%, Table 3, entry 11) and 36 (78%, Table 3, entry 12) respectively in high

• our study, the glycosylation of per-O-acetylated glucal 1 with aliphatic alcohols 12–19 showed better α-selectivities as compared to the per-O-benzylated glucal 3. However, with amino acid derivatives 20 and 21 and monosaccharides 22–24 as acceptors, similar α-selectivities were attained with both

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

• ) in the ratios ~1:1.9:2.8:2.2:2.1 (detector response data). In the present work, 2-O-methyl-6-deoxyhexose was identified as L-Rha2Me by GLC, GLC–MS and NMR (see below). Substitution patterns of the monosaccharides in the OPS were determined using alkylation analysis. Earlier, 2,3,4,6-tetra-O

• degradation was used, which included periodate oxidation of the vicinal hydroxy groups in the monosaccharides, mild acidic hydrolysis at the linkages of the destroyed sugar residues, and borohydride reduction of aldehyde groups before and after hydrolysis [17]. Based on the methylation analysis data (see

• spin systems for glycerol (Gro) derived from the 2-substituted Xyl and manno (Rha)- and galacto (Fuc)-configurated monosaccharides (Scheme 1). The spectra of compound 2 also showed signals for a methyl group (δH 3.47–3.48, δC 59.9). The values of 13C NMR chemical shifts of the C-5 signals of Rha and

Dicarboxylic esters: Useful tools for the biocatalyzed synthesis of hybrid compounds and polymers

• Ivan Bassanini,
• Karl Hult and
• Sergio Riva

Beilstein J. Org. Chem. 2015, 11, 1583–1595, doi:10.3762/bjoc.11.174

• obtained (i.e., 13a) were then used either to acylate monosaccharides (i.e., galactose to give 13b) in order to increase the solubility of the parent compounds in aqueous solutions (Figure 4) or as co-monomers in radical (AIBN)-catalyzed polymerizations (see next paragraph). In recent years linking

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

• these considerations sialyl phosphate building blocks 4 and 5 [14] were selected for automated glycan assembly using monosaccharides (Scheme 1). The synthesis of building block 4 commenced with the placement of a C-9 Fmoc protecting group on thioglycoside 1 [14] to produce 2. Installation of O

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

• , monosaccharides, fibrous proteins (collagens), glycosaminoglycans (GAGs), and proteoglycans (PGs). The latter are complex proteins containing at least one covalently bound glycosaminoglycan part [3]. GAGs are long, unbranched polysaccharides comprising repeating disaccharide units, which are constituted of a

Release of β-galactosidase from poloxamine/α-cyclodextrin hydrogels

• César A. Estévez,
• José Ramón Isasi,
• Eneko Larrañeta and
• Itziar Vélaz

Beilstein J. Org. Chem. 2014, 10, 3127–3135, doi:10.3762/bjoc.10.330

• , lactose must be attacked by substrate-specific enzymes present in the digestive system, resulting in the production of monosaccharides, which are readily absorbed through the intestinal membrane. The intolerance to lactose is a clinical syndrome related to the intake of lactose characterized by the

Synthesis and characterization of pH responsive D-glucosamine based molecular gelators

• Navneet Goyal,
• Hari P. R. Mangunuru,
• Bargav Parikh,
• Sonu Shrestha and
• Guijun Wang

Beilstein J. Org. Chem. 2014, 10, 3111–3121, doi:10.3762/bjoc.10.328

• research. Furthermore, they may be derived from abundant renewable resources. We have studied the selective functionalization of monosaccharides, such as glucose and glucosamine, and obtained effective low molecular weight gelators for both organic solvents and aqueous mixtures [35][36][37][38][39][40

• acids much more readily which results in pH responsive triggered release organogel or hydrogels, provided that the derivatives of compound 3 are effective gelators. Results and Discussion In order to understand the scope of functionalization on monosaccharides and the structure influence of the

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

• ) proceeded with a similar product distribution as 3. Glycosylation with 4-pentenol (6) (Table 2, entry 2) also provided products up to the trisaccharide with good yield. Higher yields of trisaccharides could be obtained by using the monosaccharides 7 and 8 as the initial acceptors, which also provided

Synthesis of aromatic glycoconjugates. Building blocks for the construction of combinatorial glycopeptide libraries

• Markus Nörrlinger and
• Thomas Ziegler

Beilstein J. Org. Chem. 2014, 10, 2453–2460, doi:10.3762/bjoc.10.256

• monosaccharides 11 in 53–76% yield. The medium yields in case of 11b–d (Table 1, entries 2–4) were due to some decomposition during chromatographic purification. Nevertheless, in our hands, HBTU was superior to other peptide coupling reagents because it resulted in the highest yields of compounds 11. HBTU was

Expanding the scope of cyclopropene reporters for the detection of metabolically engineered glycoproteins by Diels–Alder reactions

• Anne-Katrin Späte,
• Verena F. Schart,
• Julia Häfner,
• Andrea Niederwieser,
• Thomas U. Mayer and
• Valentin Wittmann

Beilstein J. Org. Chem. 2014, 10, 2235–2242, doi:10.3762/bjoc.10.232

• -GlcNAcylated proteins). Subsequently, a ligation reaction is performed to visualize the glycan. Synthesis of the cyclopropene-modified hexosamine derivatives 1 and 2. Labeling strategy for metabolically incorporated monosaccharides. Supporting Information Additional MOE experiments and 1H and 13C NMR spectra

Bifunctional dendrons for multiple carbohydrate presentation via carbonyl chemistry

• Davide Bini,
• Francesco Nicotra and
• Laura Cipolla

Beilstein J. Org. Chem. 2014, 10, 1686–1691, doi:10.3762/bjoc.10.177

• -fucopyranosyloxyamine [18] were used as sample monosaccharides for the conjugation of the dendron (Scheme 1). Synthesis of dendrons Zero, first and second generation heterobifunctional dendrons 1–3 were synthesized starting from 9-decen-1-ol (12) or selected building blocks 13 and 14 (Scheme 2) [11] by esterification

Expedient synthesis of 1,6-anhydro-α-D-galactofuranose, a useful intermediate for glycobiological tools

• Luciana Baldoni and
• Carla Marino

Beilstein J. Org. Chem. 2014, 10, 1651–1656, doi:10.3762/bjoc.10.172

• procedures was used to afford polymers to explore their possible applications in the field of biochemistry and pharmacology, as their properties differ from those of the corresponding monosaccharides, and they have a high density of functional groups that can be modified to obtain novel materials [14][15

Photoswitchable precision glycooligomers and their lectin binding

• Daniela Ponader,
• Sinaida Igde,
• Marko Wehle,
• Katharina Märker,
• Mark Santer,
• David Bléger and
• Laura Hartmann

Beilstein J. Org. Chem. 2014, 10, 1603–1612, doi:10.3762/bjoc.10.166

• ; multivalent glycosystems; photoswitch; precision polymer; Introduction Carbohydrate ligand–receptor interactions underpin many important processes in biology, for example in host-pathogen interactions [1][2]. Although monosaccharides usually exhibit only low binding affinities, nature is able to obtain high

• affinity carbohydrate ligands by displaying several monosaccharides/oligosaccharides on a protein scaffold or through a patch of lipids. This is known as the glycocluster effect or the multivalent presentation of sugar ligands [3][4]. This strategy can also be employed for the synthesis of carbohydrate

The search for new amphiphiles: synthesis of a modular, high-throughput library

• George C. Feast,
• Thomas Lepitre,
• Xavier Mulet,
• Charlotte E. Conn,
• Oliver E. Hutt,
• G. Paul Savage and
• Calum J. Drummond

Beilstein J. Org. Chem. 2014, 10, 1578–1588, doi:10.3762/bjoc.10.163

• phase behaviour, despite the relatively small structural difference (epimers) between the two monosaccharides. Xylose does not bear the 6-position side-chain alcohol so it takes up a significantly smaller volume. Lactose is a disaccharide so it has a much larger head-group volume. The four azido-sugars

Multichromophoric sugar for fluorescence photoswitching

• Stéphane Maisonneuve,
• Rémi Métivier,
• Pei Yu,
• Keitaro Nakatani and
• Juan Xie

Beilstein J. Org. Chem. 2014, 10, 1471–1481, doi:10.3762/bjoc.10.151

• ] (compound 2, Figure 2) so as to take advantage of this sugar-based “platform” to get a specific molecular architecture and to study the energy transfer and photo-switching efficiency. To the best of our knowledge, readily available monosaccharides have been rarely used to develop multichromophoric

• -functionalized moieties [18][19][20]. Monosaccharides can be readily functionalized with several propargyl groups to synthesize, using click chemistry, multivalent neoglycoconjugates for recognition studies with carbohydrate-binding proteins (lectins) [21][22][23][24] or to develop light-harvesting antenna

Molecular recognition of surface-immobilized carbohydrates by a synthetic lectin

• Melanie Rauschenberg,
• Eva-Corrina Fritz,
• Christian Schulz,
• Tobias Kaufmann and
• Bart Jan Ravoo

Beilstein J. Org. Chem. 2014, 10, 1354–1364, doi:10.3762/bjoc.10.138

• selectivity of the synthetic lectin HisHis for NANA and Gal versus Glc and Man. Both the selectivity and the high affinity of the synthetic lectin could be demonstrated in competition experiments with monosaccharides, disaccharides and heparin-type polysaccharides. The results obtained here demonstrate – for

Design and synthesis of multivalent neoglycoconjugates by click conjugations

• Feiqing Ding,
• Li Ji,
• Ronny William,
• Hua Chai and
• Xue-Wei Liu

Beilstein J. Org. Chem. 2014, 10, 1325–1332, doi:10.3762/bjoc.10.134

• conditions to alkyne 2a and a series of azido-linked monosaccharides 3f, 3g and 3h as well as the propargyl disaccharide 2d with α-GlaNAc azido 3g which were also obtained in good yields and selectivities (Table 3, entries 9–13). Subsequently, to shorten the reaction times, we subjected all the click

• monovalent affinities of carbohydrate monosaccharides are comparatively low and weak. To enhance this multivalent effect, thereby increasing the binding efficiencies of carbohydrates with the coupling counterparts, there has been a constant development of new glycoconjugates such as glycodendrimers [57

Synthesis of a sucrose dimer with enone tether; a study on its functionalization

• Zbigniew Pakulski,
• Norbert Gajda,
• Magdalena Jawiczuk,
• Jadwiga Frelek,
• Piotr Cmoch and
• Sławomir Jarosz

Beilstein J. Org. Chem. 2014, 10, 1246–1254, doi:10.3762/bjoc.10.124

• designed for such receptors, sugars are the most promising due to their availability and biocompatibility. Up to date only monosaccharides have found a wide application in the synthesis of crown ether analogs [5][6]. The disaccharide scaffold is much less pronounced [7]. During the past decade we have

Olefin cross metathesis based de novo synthesis of a partially protected L-amicetose and a fully protected L-cinerulose derivative

• Bernd Schmidt and
• Sylvia Hauke

Beilstein J. Org. Chem. 2014, 10, 1023–1031, doi:10.3762/bjoc.10.102

• agent with particular activity against different forms of leukemia [13] (Figure 1). Desoxy-sugars are sometimes scarcely available from natural sources and therefore the chemical syntheses of the monosaccharides [6][14] and their assembly to oligosaccharides [15][16][17] has attracted constant attention

Biosynthesis of rare hexoses using microorganisms and related enzymes

• Zijie Li,
• Yahui Gao,
• Hideki Nakanishi,
• Xiaodong Gao and
• Li Cai

Beilstein J. Org. Chem. 2013, 9, 2434–2445, doi:10.3762/bjoc.9.281

• of Mathematics and Science, University of South Carolina Salkehatchie, Walterboro, South Carolina, 29488, USA 10.3762/bjoc.9.281 Abstract Rare sugars, referred to as monosaccharides and their derivatives that rarely exist in nature, can be applied in many areas ranging from foodstuffs to

• monosaccharides and their derivatives that rarely exist in nature (http://isrs.kagawa-u.ac.jp/activities.html) [1]. Seeberger et al. did some interesting statistical research on bacterial and mammalian glycomes, with one emphasis placed on the abundance of monosaccharide units (most abundant monosaccharides are

• these monosaccharides [7]. Recently, inspired by the “Izumoring” tree, microbial and enzymatic transformations have become a very powerful tool for the synthesis of rare sugars owing to the advancements in genomics and an increasing availability of new and robust biocatalysts. Microbial transformation

Synthesis of homo- and heteromultivalent carbohydrate-functionalized oligo(amidoamines) using novel glyco-building blocks

• Felix Wojcik,
• Sinaida Lel,
• Alexander G. O’Brien,
• Peter H. Seeberger and
• Laura Hartmann

Beilstein J. Org. Chem. 2013, 9, 2395–2403, doi:10.3762/bjoc.9.276

• ). Similar reactivities were also observed for monosaccharides 4–6, supporting the substrate scope of this approach and its suitability to access a library of differently glycosylated building blocks. Referring to larger thio-substrate β-Lac(OAc)7-SH 7 a diminished reactivity with the same previously

• introduced in the desired pattern by automated solid-phase synthesis. As a proof of principle we synthesized glycoligand 16 as a multivalent scaffold that presents two different monosaccharides. β-GlcNAc and β-Gal are exposed in alternating fashion with an overall oligomer length of six building blocks and a

• in a continuous-flow reactor using five different monosaccharides and one disaccharide. We showed that this flow set up provides excellent conversion rates with several substrates. All monosaccharides were shown to react under the same conditions with equivalent conversion rates, whereas the

De novo synthesis of D- and L-fucosamine containing disaccharides

• Daniele Leonori and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2013, 9, 332–341, doi:10.3762/bjoc.9.38

• availability of rare monosaccharides that cannot be isolated from natural sources is currently limiting the access to the synthesis and the biological evaluation of complex bacterial cell-surface glycans. Here, we report the synthesis of D- and L-fucosamine building blocks by a de novo approach from L- and D

• glycoproteins and express them on cell surfaces. This evidence makes it particularly relevant especially for the identification of novel antibacterial agents as well as vaccines [7][8][9]. Those bacterial glycans often contain unusual monosaccharides that are not present in the human body. An immune response

• (four steps, two chromatographic purifications) that after the direct oxidation–dihydroxylation–peracetylation protocol yielded the desired L-fucosamine building block L-8a (Scheme 5). Synthesis of fucosamine-containing disaccharides To facilitate the use of the bacterial monosaccharides in the glycan

Synthesis of a derivative of α-D-Glcp(1->2)-D-Galf suitable for further glycosylation and of α-D-Glcp(1->2)-D-Gal, a disaccharide fragment obtained from varianose

• Carla Marino,
• Carlos Lima,
• Karina Mariño and
• Rosa M. de Lederkremer

Beilstein J. Org. Chem. 2012, 8, 2142–2148, doi:10.3762/bjoc.8.241

• linkages of varianose (Figure 1) in accordance with the higher stability of the β-galactofuranosidic linkages [32]. After column chromatography on a Biogel P-2 column, the disaccharide in the included fraction (Figure 2A) could be separated by further chromatography from the monosaccharides (not shown). As

• (disaccharides): 100 mM NaOH, isocratically at a flow rate of 1 mL/min. Condition 2 (monosaccharides): 18 mm NaOH, isocratically, at a flow rate of 1 mL/min. Repeating unit of varianose. HPAEC-PAD analysis of disaccharide α-D-Glcp(1→2)-D-Gal (1) obtained by hydrolysis of varianose and by chemical synthesis. The

• separation was performed on a CarboPac PA-10 column under condition 1, as described in the Experimental section. (A) Varianose isolated from a P. varians culture was hydrolyzed with 0.1 M TFA for 90 min at 85 °C. The included fraction of Biogel P-2 contains monosaccharides (tR 4.4 min) and disaccharide 1 (tR

Automated synthesis of sialylated oligosaccharides

• Davide Esposito,
• Mattan Hurevich,
• Bastien Castagner,
• Cheng-Chung Wang and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2012, 8, 1601–1609, doi:10.3762/bjoc.8.183

• ; sialosides; Introduction Sialic acid (Sia) belongs to a family of nonulosonic acids, i.e., monosaccharides equipped with a carboxylic moiety and a nine-carbon backbone, which play a unique role in glycobiology. Sia-containing glycans mediate pathogen invasion [1] and are involved in signalling cascades

The use of glycoinformatics in glycochemistry

• Thomas Lütteke

Beilstein J. Org. Chem. 2012, 8, 915–929, doi:10.3762/bjoc.8.104

• ; Introduction Carbohydrates, often referred to as glycans, differ from other biopolymers such as proteins or nucleic acids in various ways. The number of different monosaccharides that are present in naturally occurring glycans is significantly higher than the number of proteogenic amino acids, or of

• nucleotides that form DNA or RNA strands [1][2]. Furthermore, the monosaccharides can be linked to each other in several ways, including the possibility to form branched structures. Another important difference between glycans, on the one hand, and proteins and nucleic acids, on the other hand, is visible in

• their biosynthesis: DNA, RNA and proteins are synthesized by copying, transcription or translation, respectively, of nucleic acids, whereas carbohydrates are built in a non-template-driven approach by the sequential action of various glycosyltransferases (GT) that add monosaccharides to an existing