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

• bacterial O-antigens have been chosen for the development of glycoconjugate vaccine candidates against infectious diseases [13][14][15][16]. As a consequence, a significant quantity of oligosaccharides is required to evaluate their immunological properties for detailed understanding of the role of O

• -antigens in the pathogenicity of the E. coli strains. Development of chemical synthetic strategies would be useful to get large quantities of the oligosaccharides. As a part of the ongoing studies on the synthesis of bacterial cell wall oligosaccharides [17][18][19], a straightforward synthesis 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

• 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

• : arabinogalactan protein; glycosyl fluoride; glycosylation; oligosaccharides; Introduction Despite numerous recent advances in the synthesis of complex oligosaccharides, unlike polypeptide or oligonucleotide assembly, their preparation remains far from a routine endeavor. The critical step in oligosaccharide

• . Glycosyl halides have also been polymerized to provide poly-orthoesters [11]. The products of these reactions are polydisperse and are isolated and treated as a mixture of oligosaccharides of varying length. While this polydispersity may not be a significant limitation in cases where the product polymers

Loose-fit polypseudorotaxanes constructed from γ-CDs and PHEMA-PPG-PEG-PPG-PHEMA

• Tao Kong,
• Lin Ye,
• Ai-ying Zhang and
• Zeng-guo Feng

Beilstein J. Org. Chem. 2014, 10, 2461–2469, doi:10.3762/bjoc.10.257

• -hydroxyethyl methacrylate); polypseudorotaxane; Introduction Cyclodextrins (CDs) are a family of cyclic oligosaccharides composed of 6, 7 or 8 glucose units linked via α-1,4-glycosidic bonds. Due to the presence of a hydrophobic inner cavity with different geometric dimensions, CDs can act as host molecules

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

• communication, signal transduction, pathogen recognition or immunological responses [1][2][3][4]. In order to investigate these processes it is essential that a large amount of the respective polysaccharide structure is available. Unfortunately, isolation of pure oligosaccharides from natural sources is

• difficult due to the micro heterogenity of naturally occurring saccharides. For this reason chemical oligosaccharide synthesis is the only alternative for providing sufficient amounts of pure material for detailed biological studies. However, the synthetic preparation of complex oligosaccharides is still

Synthesis and immunological evaluation of protein conjugates of Neisseria meningitidis X capsular polysaccharide fragments

• Laura Morelli,
• Damiano Cancogni,
• Marta Tontini,
• Alberto Nilo,
• Sara Filippini,
• Paolo Costantino,
• Maria Rosaria Romano,
• Francesco Berti,
• Roberto Adamo and
• Luigi Lay

Beilstein J. Org. Chem. 2014, 10, 2367–2376, doi:10.3762/bjoc.10.247

• conjugate vaccine [14]. Undoubtedly the recent increase of MenX infections has led to take in consideration this emerging serogroup for the development of new meningococcal vaccines [15][16]. Recently it has been reported that coupling long chain oligosaccharides from MenX CPS to the nontoxic mutant of

• glycans [26][27], lower yields were attained in the present case. This can be explained with the higher solubility in organic solvents of the short structures 11–13 employed in the present study in comparison to other reported oligosaccharides [26][27], which did not allow complete precipitation of the

• units might be required to fully mimic the polysaccharide activity, and paves the ground for a deeper understanding of the structural requirements needed to develop a conjugate vaccine based on well-defined oligosaccharides attained by chemical synthesis. The preparation of these longer chain MenX

Effect of cyclodextrin complexation on phenylpropanoids’ solubility and antioxidant activity

• Miriana Kfoury,
• David Landy,
• Lizette Auezova,
• Hélène Greige-Gerges and
• Sophie Fourmentin

Beilstein J. Org. Chem. 2014, 10, 2322–2331, doi:10.3762/bjoc.10.241

• , stability, release and bioavailability of natural compounds [10][11][12][13]. CDs are a family of cyclic oligosaccharides obtained from enzymatic degradation of starch. The most common native CDs are α-cyclodextrin (α-CD), β-cyclodextrin (β-CD) and γ-cyclodextrin (γ-CD) composed of six, seven and eight (α

End group functionalization of poly(ethylene glycol) with phenolphthalein: towards star-shaped polymers based on supramolecular interactions

• Carolin Fleischmann,
• Hendrik Wöhlk and
• Helmut Ritter

Beilstein J. Org. Chem. 2014, 10, 2263–2269, doi:10.3762/bjoc.10.235

• combination of CRP with supramolecular complex formation, e.g., by the use of cyclodextrins (CDs) [6][7][34]. The most important representatives of these cyclic oligosaccharides with respect to industrial applications consist of six (α-CD), seven (β-CD) and eight (γ-CD) glucopyranose units and have a cone

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

• carbonyl groups can be exploited for carbohydrate functionalization [15][16] by reductive amination, oxime or hydrazone formation to yield suitably functionalized saccharides (Figure 1). Given the relevance of L-fucose in mammal oligosaccharides, α-L-(2-aminoethyl) fucoside [17] and α-O-L

Clicked and long spaced galactosyl- and lactosylcalix[4]arenes: new multivalent galectin-3 ligands

• Silvia Bernardi,
• Paola Fezzardi,
• Gabriele Rispoli,
• Stefania E. Sestito,
• Francesco Peri,
• Francesco Sansone and
• Alessandro Casnati

Beilstein J. Org. Chem. 2014, 10, 1672–1680, doi:10.3762/bjoc.10.175

• activation, cell growth, differentiation and apoptosis. Among different families of lectins, the ones showing a selectivity for β-D-galactoside and β-D-galactose-terminating oligosaccharides are called galectins and play important roles in a series of pathological events such as inflammation, fibrosis, heart

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

• how easily compound 12 was obtained and the versatility of anhydro sugars as intermediates for the preparation of biologically important oligosaccharides [3], we decided to investigate the conditions to obtain it as a main product. We reasoned that during the treatment of 9 with TMSI, in addition to

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

• 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

Bis(β-lactosyl)-[60]fullerene as novel class of glycolipids useful for the detection and the decontamination of biological toxins of the Ricinus communis family

• Hirofumi Dohi,
• Takeru Kanazawa,
• Akihiro Saito,
• Keita Sato,
• Hirotaka Uzawa,
• Yasuo Seto and
• Yoshihiro Nishida

Beilstein J. Org. Chem. 2014, 10, 1504–1512, doi:10.3762/bjoc.10.155

• quantified by means of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and the results were discussed in terms of detection and decontamination of the deadly biological toxin in the Ricinus communis family. Keywords: fullerene; multivalent glycosystems; oligosaccharides; proteotoxins

Efficient routes toward the synthesis of the D-rhamno-trisaccharide related to the A-band polysaccharide of Pseudomonas aeruginosa

• Aritra Chaudhury,
• Sajal K. Maity and
• Rina Ghosh

Beilstein J. Org. Chem. 2014, 10, 1488–1494, doi:10.3762/bjoc.10.153

• -rhamno-trisaccharide. The application of the reported regioselective radical-mediated deoxygenation on 4,6-O-benzylidene D-manno thioglycoside (hitherto unexplored) has potential for ramification in the field of synthesis of oligosaccharides based on 6-deoxy hexoses. Keywords: A-band polysaccharide; D

• -rhamno-trisaccharide; deoxygenation on thioglycoside; multivalent glycosystems; one-pot sequential glycosylation; Pseudomonas aeruginosa; Introduction With the firm establishment of the critical roles played by oligosaccharides in diverse biological processes [1][2][3][4], the field of oligosaccharide

Carbohydrate PEGylation, an approach to improve pharmacological potency

• M. Eugenia Giorgi,
• Rosalía Agusti and
• Rosa M. de Lederkremer

Beilstein J. Org. Chem. 2014, 10, 1433–1444, doi:10.3762/bjoc.10.147

• , instead of hydrazide-PEGs, generated a more stable oxime linkage with the carbohydrate aldehydes. Similar to the other gonadotropins, TSH is a glycosylated protein, and the role of the N-linked oligosaccharides is well established. The effect of PEG size and mono- vs multi-PEGylation was compared both in

A complete series of 6-deoxy-monosubstituted tetraalkylammonium derivatives of α-, β-, and γ-cyclodextrin with 1, 2, and 3 permanent positive charges

• Martin Popr,
• Simona Hybelbauerová and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2014, 10, 1390–1396, doi:10.3762/bjoc.10.142

• ; regioselectivity; tetraalkylammonium derivatives; Introduction Cyclodextrins (CDs) are cyclic oligosaccharides with the shape of a hollow truncated cone, first described in 1891 by Villiers [1]. Naturally occurring CDs are named α-, β- and γ-cyclodextrin and are composed of 6, 7 or 8 D-glucopyranose units

Biantennary oligoglycines and glyco-oligoglycines self-associating in aqueous medium

• Svetlana V. Tsygankova,
• Alexander A. Chinarev,
• Alexander B. Tuzikov,
• Nikolai Severin,
• Alexey A. Kalachev,
• Juergen P. Rabe,
• Alexandra S. Gambaryan and
• Nicolai V. Bovin

Beilstein J. Org. Chem. 2014, 10, 1372–1382, doi:10.3762/bjoc.10.140

• modification by the amino group with mono- or oligosaccharides dramatically increased their solubility in water. This may support their antiviral action (see below), because glycopeptides act topically, in the respiratory tract, and are administered as a spray. We then investigated the ability of synthesized

• inhibition or the blocking of the binding of the influenza virus with target cells [15]. Monovalent oligosaccharides are incapable of an efficient competition for analogous glycans on the cell surface due to the low binding constant with viral hemagglutinin. An attractive way of increasing the affinity of a

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

• the key reaction step. The copper-catalyzed regioselective click reaction was tremendously accelerated with assistance of microwave irradiation. Keywords: click conjugations; copper-catalyzed; microwave irradiation; multivalent glycosystems; neoglycoconjugates; one-pot; Introduction Oligosaccharides

• few examples of oligosaccharides and glycopeptides mimics have so far been prepared by a click chemistry strategy [40][41][42][43][44][45][46][47][48]. Most recently, we developed a strategy for the synthesis of 3-amino-2,3-dideoxysugars using a regio- and stereoselective tandem hydroamination

• glycoscience, because triazole-linked glycoconjugates can exhibit very interesting biological properties, offering a convenient access toward oligosaccharides, glycopeptide mimics, or multivalent carbohydrate systems [40][41][42][43][44][45][46][47][48]. Their further application in molcecular biosystems is

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

Silver and gold-catalyzed multicomponent reactions

• Giorgio Abbiati and
• Elisabetta Rossi

Beilstein J. Org. Chem. 2014, 10, 481–513, doi:10.3762/bjoc.10.46

• particular molecules or were employed as a key step for the synthesis of more complex structures in domino approaches. For example, Che, Wong and co-workers successfully applied A3-coupling to aldehyde-containing oligosaccharides 8 [38]. The best catalyst for this reaction was 10 mol % of the [Au(C^N)Cl2

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

• rare sugar [25]. More interestingly, D-psicose has also been used to prepare several D-psicose containing disaccharides, aiming to learn the function of the rare sugar containing oligosaccharides and glycosides [27]. D-Psicose can be prepared through the epimerization of D-fructose at C-3 catalyzed by

• engineered Corynebacterium glutamicum was used to produce guanosine-5’-diphosphate (GDP)-L-fucose, the precursor of fucosyl-oligosaccharides, from glucose and mannose [95]. L-Fucose (or its analogs) can also be prepared in vitro enzymatically in a three-step procedure (Scheme 16) [96]. Firstly, L-fuculose-1

Gold-catalyzed glycosidation for the synthesis of trisaccharides by applying the armed–disarmed strategy

• Abhijeet K. Kayastha and
• Srinivas Hotha

Beilstein J. Org. Chem. 2013, 9, 2147–2155, doi:10.3762/bjoc.9.252

• Abhijeet K. Kayastha Srinivas Hotha Department of Chemistry, Indian Institute of Science Research and Education, Pune-411 008, India 10.3762/bjoc.9.252 Abstract The synthesis of oligosaccharides is still a challenging task as there is no universal glycosyl donor for the synthesis of all

• oligosaccharides. The gold catalysis for glycosidation reactions, in which alkynylated glycosides are used, has emerged as one of the versatile options in this regard. A cleavage of the interglycosidic bond that was thought to be due to the higher reaction temperature and the acidic medium was observed during the

• process, the saccharide unit that is donating its glycon is called a glycosyl donor, whereas the saccharide that is accepting the glycon is referred to as glycosyl acceptor or aglycon. The synthesis of oligosaccharides is still a formidable task in spite of the development of various methods. There is

Synthesis of mucin-type O-glycan probes as aminopropyl glycosides

• David Benito-Alifonso,
• Rachel A. Jones,
• Anh-Tuan Tran,
• Hannah Woodward,
• Nichola Smith and
• M. Carmen Galan

Beilstein J. Org. Chem. 2013, 9, 1867–1872, doi:10.3762/bjoc.9.218

• . Keywords: glycosylation; mucin-type oligosaccharides; O-glycans; oligosaccharide synthesis; Introduction Mucins are heavily glycosylated glycoproteins that may be membrane-associated or secreted in gel form and play an important biological role in the respiratory and intestinal tracks [1][2][3]. Mucins

• create a plethora of potential binding sites for commensal and pathogenic microbes, and are also ligands for the targeting of leucocytes to endothelial cells. Secreted mucins found in the intestinal mucus gel and the glycocalyx contain hundreds of different mucin type, O-linked oligosaccharides and

• -deoxy-D-galactose to serine or threonine. This saccharide forms the inner part of the characteristic core oligosaccharides from where glycans are extended through common core (di- and trisaccharide) structures, cores 1–8 [6][7][8]. The mucin-type oligosaccharides identified to date have remarkable

Straightforward synthesis of a tetrasaccharide repeating unit corresponding to the O-antigen of Escherichia coli O16

• Manas Jana and
• Anup Kumar Misra

Beilstein J. Org. Chem. 2013, 9, 1757–1762, doi:10.3762/bjoc.9.203

• virulence property of the pathogen, several reports appeared in the past on the development of glycoconjugate based therapeutics against bacterial infections [10][11][12]. Detailed biological studies of the glycoconjugates require a significant quantity of the oligosaccharides, which is difficult to isolate

• from natural sources. Hence, the development of chemical synthetic strategies for the synthesis of oligosaccharides is essential. In this context, a straightforward synthesis of the tetrasaccharide corresponding to the O-antigen of E. coli O16 as its p-methoxyphenyl glycoside has been developed and is

Short synthesis of the common trisaccharide core of kankanose and kankanoside isolated from Cistanche tubulosa

• Goutam Guchhait and
• Anup Kumar Misra

Beilstein J. Org. Chem. 2013, 9, 705–709, doi:10.3762/bjoc.9.80

• from C. tubulosa and have shown promising medicinal activity such as hepatoprotective and vasorelaxant activities [4][5][6]. Most of the compounds isolated from C. tubulosa and related species are phenylethyl oligosaccharides, iridoids, terpenes and lignans [4][5][6][7]. Recently, Yoshikawa et al

• . isolated and characterized a significant number of phenylethyl oligosaccharides, which include kankanose, kankanoside F, H1, H2, I, etc. [4][5]. Since C. tubulosa has been used in the folk medicine for several years, it is beneficial to find out the biological activities of the individual compounds present

• best option to gain access to these compounds on a large scale. A few reports are available in the literature for the synthesis of phenylethyl oligosaccharides [8][9]. In this context, we developed a synthetic strategy for the synthesis of the common trisaccharide core of kankanose, kankanoside F, H1

Synthesis and testing of the first azobenzene mannobioside as photoswitchable ligand for the bacterial lectin FimH

• Vijayanand Chandrasekaran,
• Katharina Kolbe,
• Femke Beiroth and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2013, 9, 223–233, doi:10.3762/bjoc.9.26

• portion is complexed in the carbohydrate binding site, the first mannoside does not add significantly to the affinity and this is in accordance with other studies on the complexation of oligosaccharides by FimH [11]. However, this mannose ring acts as a spacer moiety, sticking out straight from the CRD