From supramolecular chemistry to the nucleosome: studies in biomolecular recognition

• Marcey L. Waters

Beilstein J. Org. Chem. 2016, 12, 1863–1869, doi:10.3762/bjoc.12.175

• (after Sara Butterfield) [33], Sarah–Zachtide – which investigates a carbohydrate–π interaction (after Sarah Kiehna and Zachary Laughrey) [27][28], Bobtide – which contains a cation–π interaction with KMe3 (trimethyllysine) and was the most stable β-hairpin reported at the time (after Robert Hughes) [22

Synthesis of the C8’-epimeric thymine pyranosyl amino acid core of amipurimycin

• Pramod R. Markad,
• Navanath Kumbhar and
• Dilip D. Dhavale

Beilstein J. Org. Chem. 2016, 12, 1765–1771, doi:10.3762/bjoc.12.165

• ; carbohydrate; peptidyl nucleosides; Introduction Peptidyl nucleoside antibiotics are a class of complex molecules that encompass an extensive array of natural products [1]. The notable structural features of peptidyl nucleosides are responsible for their miscellaneous biological activities such as antitumor

• of 1 is not known. The reported methodologies are mainly focused on construction of the exigent central pyranosyl amino acid fragment with or without the C3’-branched chain and nucleobase, frequently using carbohydrate substrate [6][7][8][9][10][11][12][13][14][15]. In a non-carbohydrate approach

• , Garner and co-workers have exploited a cycloaddition pathway between a poly-oxygenated diene and Garner’s aldehyde for constructing the carbohydrate core of amipurimycin [9]. Recently, Datta and co-workers reported the first synthesis of a fully-functionalized thymine analogue of amipurimycin, utilizing

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

• serotype 3 oligosaccharides have been developed and were applied to other uronic acid containing carbohydrate structures [21][22]. The first method uses only glucose building blocks to assemble oligosaccharides and introduces the C6 carboxylic acid moieties via a late-stage oxidation. Using this method

• conclusion, we have developed an efficient method for the synthesis of S. pneumoniae serotype 3 CPS structures. The products of these syntheses are currently used in the development of synthetic carbohydrate conjugate vaccines. Disaccharide repeating unit of the S. pneumoniae serotype 3 CPS. Building blocks

Mutagenic activity of quaternary ammonium salt derivatives of carbohydrates

• Barbara Dmochowska,
• Karol Sikora,
• Anna Woziwodzka,
• Jacek Piosik and
• Beata Podgórska

Beilstein J. Org. Chem. 2016, 12, 1434–1439, doi:10.3762/bjoc.12.138

• . The polymers (oligosaccharides) of D-glucose found, for example, in wood (cellulose) and D-glucosamine present in shells of crabs and insects (chitin), are the widely known ones [1][2]. Another class of carbohydrate biopolymer derivatives – D-ribose and 2-deoxy-D-ribose – constitutes the backbone of

• observations on the pronounced mutagenic activity of QAS derivatives with two carbon atom spacers dividing the sugar moiety and the ammonium group [22], we investigated the mutagenic activity of newly synthesized QAS with a carbohydrate spacer containing six carbon atoms. Two different bacterial mutagenicity

• containing a carbohydrate moiety with a two-carbon atom linker in the Vibrio harveyi bioluminescence assay. Here, we provide evidence for the mutagenic potential of corresponding QAS–carbohydrate derivatives with a longer, six-carbon atom linker. This suggests that the introduction of a longer hydrocarbon

A robust synthesis of 7,8-didemethyl-8-hydroxy-5-deazariboflavin

• Matthias Bender,
• Henrik Mouritsen and
• Jens Christoffers

Beilstein J. Org. Chem. 2016, 12, 912–917, doi:10.3762/bjoc.12.89

• carbohydrate chemistry and might then allow purification and characterization of intermediate products. While we were following the synthetic approach by Yoneda et al. with a protected ribose derivative, Foss and co-workers were obviously facing the same preparative problem. To our surprise and delight (that

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

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

• carbohydrate and glycolipid parts [15] followed by fractionation of the released water-soluble carbohydrate portion by Sephadex G-50 Superfine size-exclusion chromatography. It was demonstrated that the OPS contained 2-O-methyl-6-deoxyhexose, L-rhamnose (Rha), D-fucose (Fuc), D-xylose (Xyl), and D-glucose (Glc

Biosynthesis of α-pyrones

• Till F. Schäberle

Beilstein J. Org. Chem. 2016, 12, 571–588, doi:10.3762/bjoc.12.56

• a ppyS homologue. However, instead of the syntenic genomic region where pseudomonads usually harbor the ppyS homologue, it appeared that the gene has inserted between genes belonging to carbohydrate metabolism in P. putida BW11M1. An in-frame deletion mutant of the ppyS homologue was constructed and

A selective and mild glycosylation method of natural phenolic alcohols

• Mária Mastihubová and
• Monika Poláková

Beilstein J. Org. Chem. 2016, 12, 524–530, doi:10.3762/bjoc.12.51

• an iodobromonium ion) results in a carbohydrate-derived oxocarbonium ion that functions as the reactive intermediate [35]. In the first step, acceptor 6b and glucopyranosyl bromide 13 as the donor were selected and tested in the presence of the above mentioned promoters (see Table 1, entries 1–4) in

Recent advances in N-heterocyclic carbene (NHC)-catalysed benzoin reactions

• Rajeev S. Menon,
• Akkattu T. Biju and
• Vijay Nair

Beilstein J. Org. Chem. 2016, 12, 444–461, doi:10.3762/bjoc.12.47

• influence of these catalysts on the diastereoselectivity of the reaction was also studied using NMR techniques. An NHC-catalysed intramolecular benzoin condensation of carbohydrate-derived dialdehydes has been applied for the construction of carbocyclic sugars. Diastereoselective benzoin reactions of manno

• enals and β-oxo sulfones. Intramolecular benzoin condensation of carbohydrate-derived dialdehydes. Enantioselective intramolecular benzoin reactions of N-tethered keto-aldehydes. Asymmetric cross-benzoin reactions promoted by camphor-derived catalysts. NHC-Brønsted base co-catalysis in a benzoin–Michael

Self and directed assembly: people and molecules

• Tony D. James

Beilstein J. Org. Chem. 2016, 12, 391–405, doi:10.3762/bjoc.12.42

• group were developing carbohydrate receptors from what looked like simple molecules requiring just one or two steps to synthesize. Therefore, while working with the late Takaaki Harada, we developed a simple colorimetric system able to “read-out” the chirality of sugars. The system we developed used the

Natural products from microbes associated with insects

• Christine Beemelmanns,
• Huijuan Guo,
• Maja Rischer and
• Michael Poulsen

Beilstein J. Org. Chem. 2016, 12, 314–327, doi:10.3762/bjoc.12.34

• monophyletic termite subfamily Macrotermitinae propagates a basidiomycete fungal cultivar Termitomyces, which serves as a major food source for the termite colony [90]. The domestication of Termitomyces facilitates an increase in carbohydrate decomposition capacity relative to that of other higher termites [91

Spiro-fused carbohydrate oxazoline ligands: Synthesis and application as enantio-discrimination agents in asymmetric allylic alkylation

• Jochen Kraft,
• Martin Golkowski and
• Thomas Ziegler

Beilstein J. Org. Chem. 2016, 12, 166–171, doi:10.3762/bjoc.12.18

• benchmark test for selectivity, the palladium-catalyzed asymmetric addition of dimethyl malonate to 1,3-diphenylallyl acetate was often used in the literature for testing the scope of carbohydrate derived ligands for this purpose [9][10][11][12][13]. For instance, Kunz and Gläser have demonstrated the

• stereo-differentiating potential of carbohydrate ligands in this type of reaction where their gluco-PHOX ligand, derived from glucosamine, resulted in a high enantiomeric excess of up to 98% [14]. Recently, Vidal et al. reported on a spiro-bis(isooxazoline) ligand A (Figure 1) [15] prepared via 1,3

• substitution product only in traces. The authors attributed the inefficiency of ligand A to the cleavage of the spiro moiety resulting in the formation of thermodynamically more stable aromatic isoxazole B (Figure 1). As part of our ongoing research program towards the design of carbohydrate derived ligands

Exploring architectures displaying multimeric presentations of a trihydroxypiperidine iminosugar

• Camilla Matassini,
• Stefania Mirabella,
• Andrea Goti,
• Inmaculada Robina,
• Antonio J. Moreno-Vargas and
• Francesca Cardona

Beilstein J. Org. Chem. 2015, 11, 2631–2640, doi:10.3762/bjoc.11.282

• glycosidases. Keywords: dendrimers; glycosidase inhibitors; iminosugars; multivalency; piperidine alkaloids; Introduction Iminosugars are well-known naturally occurring glycomimetics with a nitrogen atom replacing the endocyclic oxygen, mainly recognized as inhibitors of carbohydrate-processing enzymes

• (glycosidases) [1][2]. In quite sharp contrast the multivalent effect, widely investigated in the field of carbohydrate–lectin interactions [3], has remained essentially unexplored concerning glycosidase inhibition up to 2010. Indeed, the first examples of multivalent iminosugars gave disappointing results in

Synthesis of bi- and bis-1,2,3-triazoles by copper-catalyzed Huisgen cycloaddition: A family of valuable products by click chemistry

• Zhan-Jiang Zheng,
• Ding Wang,
• Zheng Xu and
• Li-Wen Xu

Beilstein J. Org. Chem. 2015, 11, 2557–2576, doi:10.3762/bjoc.11.276

• mild conditions without the Cu(І). Notably, the CuAAC reaction between the terminal alkyne of 36 and various azides provided the desired bistriazoles 37 in good yield (Scheme 14). Bistriazoles have potential application in the synthesis of surfactants after introducing the carbohydrate moiety. In 2012

Versatile synthesis and biological evaluation of novel 3’-fluorinated purine nucleosides

• Hang Ren,
• Haoyun An,
• Paul J. Hatala,
• William C. Stevens Jr,
• Jingchao Tao and
• Baicheng He

Beilstein J. Org. Chem. 2015, 11, 2509–2520, doi:10.3762/bjoc.11.272

• ’-difluorocytidine has been routinely utilized to treat solid tumors [30]. However, 3’-fluorine-modified nucleosides have not been well-studied because of the challenges associated with the synthesis of modified carbohydrate moieties [31][32][33][34][35]. As a result, 3’-fluoro-6-heterocyclic-substituted purine

• the protecting groups [35]. Compound 2 has also been synthesized starting from xylofuranoside by manipulating the protecting groups on the carbohydrate moiety [36]. De Clercq and co-workers [37] developed a protocol for the synthesis of 3’-fluororibofuranose in 10 steps, and it requires epoxide

Biocatalysis for the application of CO₂ as a chemical feedstock

• Apostolos Alissandratos and
• Christopher J. Easton

Beilstein J. Org. Chem. 2015, 11, 2370–2387, doi:10.3762/bjoc.11.259

• (RuBisCO). The glycerate 2 is subsequently phosphorylated with ATP for the production of 1,3-bisphosphoglycerate (3), which is in turn reduced with NADPH to 3-phosphoglyceraldehyde (4). For every six equivalents of the aldehyde 4, one is diverted to carbohydrate biosynthesis, while the other five are used

Synthesis of D-fructose-derived spirocyclic 2-substituted-2-oxazoline ribosides

• Madhuri Vangala and
• Ganesh P. Shinde

Beilstein J. Org. Chem. 2015, 11, 2289–2296, doi:10.3762/bjoc.11.249

• in toluene through nucleophilic addition of electron-rich nitriles to the oxacarbenium ion intermediate of 1,2;3,4-di-O-isopropylidene-β-D-psicofuranose derivatives with concomitant intramolecular trapping of the C2 hydroxymethyl group on the electrophilic nitrilium carbon. These carbohydrate-derived

• carbohydrate chemistry, they are versatile intermediates in the synthesis of N-linked glycoproteins [20][21][22]. In the context of carbohydrate chemistry, there are two possible regioisomers for glycooxazolines. Firstly, the C1 O-linked 1,2-glycooxazolines (Figure 1, 5) are formed by intramolecular

• applied them to the synthesis of α(1→5)-arabinan [38]. Thus, the exploration of carbohydrate-based oxazolines [39][40] has been limited to serve as glycosyl donors or as intermediates for N-glycan synthesis. Although, a few pyranose-based oxazoline frameworks are known [41], the corresponding furanoid

Coupling of α,α-difluoro-substituted organozinc reagents with 1-bromoalkynes

• Artem A. Zemtsov,
• Alexander D. Volodin,
• Vitalij V. Levin,
• Marina I. Struchkova and
• Alexander D. Dilman

Beilstein J. Org. Chem. 2015, 11, 2145–2149, doi:10.3762/bjoc.11.231

• , unique stereoelectronic properties of the CF2-unit may be exploited in conformational analysis [3][4][5], carbohydrate and peptide research [6][7], and reaction engineering [8][9]. Typically, the difluoromethylene fragment is created by deoxyfluorination, which requires harsh or hazardous conditions [10

Synthesis, antimicrobial and cytotoxicity evaluation of new cholesterol congeners

• Mohamed Ramadan El Sayed Aly,
• Hosam Ali Saad and
• Shams Hashim Abdel-Hafez

Beilstein J. Org. Chem. 2015, 11, 1922–1932, doi:10.3762/bjoc.11.208

• pharmacophoric conjugates through CuAAC. Basically, these conjugates included cholesterol and 1,2,3-triazole moieties, while the third, the pharmacophore, was either a chalcone, a lipophilic residue or a carbohydrate tag. These compounds were successfully prepared in good yields and characterized by NMR, MS and

Towards inhibitors of glycosyltransferases: A novel approach to the synthesis of 3-acetamido-3-deoxy-D-psicofuranose derivatives

• Maroš Bella,
• Miroslav Koóš and
• Chun-Hung Lin

Beilstein J. Org. Chem. 2015, 11, 1547–1552, doi:10.3762/bjoc.11.170

• simulate the shape and functionality of the natural substrates in the ground and/or the transition state (TS) of the enzymatic reaction [14]. In the case of GTs inhibitors, the carbohydrate mimetics that imitate the TS of the enzymatic reactions should exhibit a higher inhibition activity than the natural

• carbohydrate substrates [9][16]. Investigations of the catalytic mechanism of inverting glycosyltransferases [18] and N-acetylglucosaminyltransferase I [19] by employing ab initio calculations resulted in the design of inhibitors based on carbohydrate mimetics that simulate the transition state of the

Synthesis and spectroscopic properties of β-triazoloporphyrin–xanthone dyads

• Dileep Kumar Singh and
• Mahendra Nath

Beilstein J. Org. Chem. 2015, 11, 1434–1440, doi:10.3762/bjoc.11.155

• porphyrins with diverse functionalities such as quinolone [19], ferrocene [20], carbohydrate [21] and fullerene [22] through a copper(I)-catalyzed Huisgen–Sharpless–Meldal 1,3-dipolar cycloaddition reaction [23][24]. Some of these triazolo-bridged porphyrin dyads have shown an efficient intramolecular energy

Selected synthetic strategies to cyclophanes

• Sambasivarao Kotha,
• Mukesh E. Shirbhate and
• Gopalkrushna T. Waghule

Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142

• cyclized product. The cleavage of the acetate groups with sodium methoxide in methanol gave the glycophane (a glycophane is a hybrid of carbohydrate and cyclophane) 143 (27%, Scheme 21). The synthesis of fullerene-related molecules with high binding affinity and/or high selectivity is an active research

• ] have reported the synthesis of a glycotriazolophane 309 (carbohydrate–triazole–cyclophane hybrid) from a sugar amino acid via a copper-catalyzed azide-alkyne cycloaddition sequence. An aminosugar acid was identified as a useful building block to generate cyclophanes. Thus, the treatment of 304 with

Are D-manno-configured Amadori products ligands of the bacterial lectin FimH?

• Tobias-Elias Gloe,
• Insa Stamer,
• Cornelia Hojnik,
• Tanja M. Wrodnigg and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2015, 11, 1096–1104, doi:10.3762/bjoc.11.123

• E. coli bacteria by means of molecular docking and bacterial adhesion studies. It turns out that Amadori rearrangement products have a limited activity as inhibitors of bacterial adhesion because the β-C-glycosidically linked aglycone considerably hampers complexation within the carbohydrate binding

• aromatic moiety with the so-called tyrosine gate at the entrance of the carbohydrate binding site, formed by Y48 and Y137. Additional interactions exerted by extended aglycone portions can further improve ligand affinity for FimH; for example ortho-chloro substitution of the phenyl ring (compounds 2 and 5

• consideration of Amadori products 9 and 10 as FimH ligands The complexation of MeMan (1, cf. Figure 1) as the most simple FimH ligand in the carbohydrate binding site of FimH has been described in detail [10]. It is depicted in a simplified cartoon fashion in Figure 2. The α-configured aglycone moiety (OCH3 in

Multivalency as a chemical organization and action principle

• Rainer Haag

Beilstein J. Org. Chem. 2015, 11, 848–849, doi:10.3762/bjoc.11.94

• [8][9][10][11][12] and studies the scope of multivalent lectin-glycointeractions in galectins [13], with iminosugars [14] and carbohydrate mimetics [15]. This Thematic Series in the Beilstein Journal of Organic Chemistry also investigates the enhanced multivalent binding of protein scaffolds [16