Enzymatic separation of epimeric 4-C-hydroxymethylated furanosugars: Synthesis of bicyclic nucleosides

• Neha Rana,
• Manish Kumar,
• Vinod Khatri,
• Jyotirmoy Maity and
• Ashok K. Prasad

Beilstein J. Org. Chem. 2017, 13, 2078–2086, doi:10.3762/bjoc.13.205

• hydroxy groups present in different sugars and sugar moieties of synthetic or naturally occurring glycosides, nucleosides, etc. Gotor et al. [11] have reported a lipase-mediated acylation of an equimolecular mixture of D/L-thymidine with acetonoxime levulinate as acylating agent and Pseudomonas cepacia

Intramolecular glycosylation

• Xiao G. Jia and
• Alexei V. Demchenko

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

• ). With primary glycosyl acceptors, such as 66 (Scheme 16), yields were slightly diminished due to the formation of the homocoupling products. Secondary alcohol acceptors were even less efficient showing a high substrate specificity of this approach. Other donor series including 2-azido and 2-deoxy sugars

Pd(OAc)₂/Ph₃P-catalyzed dimerization of isoprene and synthesis of monoterpenic heterocycles

• Dominik Kellner,
• Maximilian Weger,
• Andrea Gini and
• Olga García Mancheño

Beilstein J. Org. Chem. 2017, 13, 1807–1815, doi:10.3762/bjoc.13.175

• from renewable sources such as sugars has been considered as a competitive sustainable synthetic alternative [21][22]. Although the dimerization of isoprene is significantly more difficult compared to the dimerization of 1,3-butadiene, it would lead to synthetically useful linear monoterpenic

The chemistry and biology of mycolactones

• Matthias Gehringer and
• Karl-Heinz Altmann

Beilstein J. Org. Chem. 2017, 13, 1596–1660, doi:10.3762/bjoc.13.159

Chemical systems, chemical contiguity and the emergence of life

• Terrence P. Kee and
• Pierre-Alain Monnard

Beilstein J. Org. Chem. 2017, 13, 1551–1563, doi:10.3762/bjoc.13.155

• , and finally iv) systems could have conditioned the proliferation of functional systems. Chemical selection The investigation of synthetic pathways to biochemically relevant molecules has clearly underlined the need for some form of selection. Indeed, molecules of interest (nucleobases [57], sugars [58

• derivatives and even stabilize them [63]. The same observation was made for ribose over other sugars. Moreover, when the permeability of fatty acid vesicle bilayers towards sugars was examined, ribose was determined to have the highest diffusion rates among aldopentoses or hexoses [64], a fact that could also

Strategies toward protecting group-free glycosylation through selective activation of the anomeric center

• A. Michael Downey and
• Michal Hocek

Beilstein J. Org. Chem. 2017, 13, 1239–1279, doi:10.3762/bjoc.13.123

• ]. On the other hand, the disadvantage is the need to synthesize NDP-sugars as substrates for the GT which is typically a multistep laborious process. Another particularly interesting application of glycosyltransferases is the chemoenzymatic synthesis of nucleosides. This is an incredibly powerful tool

• isolate several exclusively β-glycosyl sulfonohydrazide (GSH) donors in very high yields (Figure 6) [92][93]. Furthermore, both C2–OH and 2-deoxy-2-NHAc saccharides were compatible with their conditions. Their initial study [92] focused on the diastereoselective glycosylation of 2-deoxy-2-NHAc sugars

• 1,2-trans-protected thiols in good to perfect stereoselectivity (Scheme 35). Furthermore, most protecting groups were compatible and the purification was simple [98]. The authors reported that the use of unprotected sugars initially proved to be slightly more difficult, due to the tendency of the

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

• ). During this study we observed common byproducts related to the reductive amination of sugars [19] (Scheme 1). All the reaction conditions tested (Table 1) showed the presence of alditol 4 as a result of sodium cyanoborohydride lack of selectivity [20] to reduce imines in the presence of aldehydes. When

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

• ][14][15]. However, most aromatic skeleton monomers are non-renewable and could generate additional environmental problems. Therefore, the selection and use of low cost, green, raw materials is critical. Sugars are a ubiquitous resource, which plays many different and important roles in the world [16

• -linker, the Friedel–Crafts cross-linking polymerization is promoted smoothly by anhydrous FeCl3 in dry 1,2-dichloroethane (DCE). The monomers were either commercially available (Sug-1) or prepared (Sug-2 and Sug-3) by benzylation of free sugars with benzyl bromide and sodium hydride. The chemical

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

• , UDP-Gal, GDP-Man, and the GTs that process them are often referred to as Leloir enzymes. In certain cases, lipid-linked sugars, e.g., dolichol phosphate saccharides and unsubstituted phosphates are also utilized. The transfer of saccharides by GTs is regio-specific and stereo-specific: depending on

• thrombin and antithrombin at 2.5 Å resolution. For the time being, this is one of the largest oligosaccharide structures ever established throughout macromolecular X-ray crystallography (Figure 12) [59]. Transporters: Soluble sugars serve many purposes in complex organisms. Their cellular exchange relies

• mediate an active uptake and efflux of various mono- and disaccharides. The low affinity of these proteins for sugars seems to be a characteristic feature of transporters involved in high turnover rates, rather than a highly specific transport at low levels of substrates. The structure of the first

From chemical metabolism to life: the origin of the genetic coding process

• Antoine Danchin

Beilstein J. Org. Chem. 2017, 13, 1119–1135, doi:10.3762/bjoc.13.111

• appearance of ribose is the following: Sugars involved in anabolism are essentially of the D-isomer type. This results from selective evolution involving competition with L-amino acids in early essential processes [33]. As a consequence, we can be fairly confident that ribose, and therefore nucleotides

• their environment. For example, there are receptors for taste with exquisite recognition of specific molecules, sugars for example. The sweet taste is triggered by a lock-and-key process in which sugars fit within a specific cavity of the receptor. This interaction can be mimicked by compounds that have

• nothing in common with sugars or with each other, such as the highly ”sweet” but completely unrelated proteins thaumatin and monellin [41]. Within cells, networks of protein interactions are mediated by rules following complementarity patterns that are yet to be discovered, but are central for the genetic

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

• resources are ideal starting materials in DOS, which aims at providing quick access to libraries of diverse molecules. To exploit the strategy, it was envisioned that different sugars could serve as precursor for the necessary alkyne–alkene and azide–alkene functionalities and could be connected through a

Conjecture and hypothesis: The importance of reality checks

• David Deamer

Beilstein J. Org. Chem. 2017, 13, 620–624, doi:10.3762/bjoc.13.60

• , simple sugars and phosphate. The organic solutes are likely to be present as very dilute solutions, so there should be a process by which they can be sufficiently concentrated to undergo chemical reactions relevant to cellular life. Energy sources must be present in the environment to drive a primitive

Novel β-cyclodextrin–eosin conjugates

• Gábor Benkovics,
• Damien Afonso,
• András Darcsi,
• Szabolcs Béni,
• Sabrina Conoci,
• Éva Fenyvesi,
• Lajos Szente,
• Milo Malanga and
• Salvatore Sortino

Beilstein J. Org. Chem. 2017, 13, 543–551, doi:10.3762/bjoc.13.52

• property can be utilized to protect the guest molecules from oxidation and degradation, to enhance their solubility and bioavailability, or to use the CD host as a drug carrier [1]. The potential application of these macrocyclic sugars in such pharmaceutical formulations required the understanding of the

Secondary metabolome and its defensive role in the aeolidoidean Phyllodesmium longicirrum, (Gastropoda, Heterobranchia, Nudibranchia)

• Alexander Bogdanov,
• Cora Hertzer,
• Stefan Kehraus,
• Samuel Nietzer,
• Sven Rohde,
• Peter J. Schupp,
• Heike Wägele and
• Gabriele M. König

Beilstein J. Org. Chem. 2017, 13, 502–519, doi:10.3762/bjoc.13.50

• yielding 11 fractions. 1H NMR analysis of these indicated the presence of chemically diverse secondary metabolites in the major fractions 3–8, whereas the hydrophilic fractions 1 and 2 merely contained sugars and the lipophilic ones, i.e., 9–11 simple lipids. Detailed UPLC–HRMS investigation was thus

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

• previously performed better than pyridine in the tin-catalyzed solvent-free regioselective benzylation or allylation of sugars [35]. The silylation rate was not appreciably influenced by tin catalysis (compare entries 2 and 3 in Table 1), although a previous report described the stoichiometric use of

Formose reaction controlled by boronic acid compounds

• Toru Imai,
• Tomohiro Michitaka and
• Akihito Hashidzume

Beilstein J. Org. Chem. 2016, 12, 2668–2672, doi:10.3762/bjoc.12.263

• macromolecular boronic acid compounds, i.e., sodium phenylboronate (SPB) and a copolymer of sodium 4-vinylphenylboronate with sodium 4-styrenesulfonate (pVPB/NaSS), respectively. The boronic acid compounds provided different selectivities; sugars of a small carbon number were formed favorably in the presence of

• SPB, whereas sugar alcohols of a larger carbon number were formed preferably in the presence of pVPB/NaSS. Keywords: boronic acid compounds; formose reaction; sodium phenylboronate; sodium 4-vinylphenylboronate/sodium 4-styrenesulfonate copolymer; sugar alcohols; sugars; Findings When an aqueous

• solution of formaldehyde is warmed in the presence of a basic catalyst, a mixture of sugars and sugar alcohols, i.e., ‘formose’, is obtained. This reaction is called ‘formose reaction’ and was first reported by Butlerow, a Russian chemist, in 1861 [1]. Studies on formose reactions have revealed that the

Formose reaction accelerated in aerosol-OT reverse micelles

• Makoto Masaoka,
• Tomohiro Michitaka and
• Akihito Hashidzume

Beilstein J. Org. Chem. 2016, 12, 2663–2667, doi:10.3762/bjoc.12.262

• mixture of sugars and sugar alcohols, called ‘formose’, from formaldehyde by heating under basic conditions. It has been considered that the formose reaction is a possible pathway for sugar formation under prebiotic conditions [1][2][3][4]. The formose reaction was first reported by Butlerow in 1861 [5

• rate-determining step of the formose reaction. It is known that glycolaldehyde acts as a cocatalyst. Thus, when the concentration of glycolaldehyde reaches a certain level, formaldehyde is consumed rapidly to form a complicated mixture of sugars predominantly via aldol reaction and aldose–ketose

• transformation in the sugar formation period. When formaldehyde is consumed quantitatively, the reaction mixture turns yellow. In the sugar degradation period, the sugars formed are decomposed dominantly through cross-Cannizzaro reaction and retro-aldol reaction to form a more complicated reaction mixture. The

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

• are, with proteins and lipids, essential constituents of living organisms because they are key biological intermediates for energy storage. In autotrophs, such as plants, sugars are converted into starch whereas for heterotrophic organisms, such as animals, they are stored as glycogen. However

• logical that D-glucose interacts weakly with native CDs due to its size and its hydrophilic property. However, from these conflicting results, Turner proposed to use kinetic measurements to determine the association constants of several sugars with β-CD [98]. This new method has been published in 2000 [99

Useful access to enantiomerically pure protected inositols from carbohydrates: the aldohexos-5-uloses route

• Felicia D’Andrea,
• Giorgio Catelani,
• Lorenzo Guazzelli and
• Venerando Pistarà

Beilstein J. Org. Chem. 2016, 12, 2343–2350, doi:10.3762/bjoc.12.227

• -promoted [28][29][30] pinacol coupling of dialdehyde derivatives). A strategy related to the latter approach relies on a base-promoted aldol condensation of aldohexos-5-uloses followed by reduction of the carbonyl group, as reported in the retrosynthetic Scheme 1. This method again uses sugars as starting

Enduracididine, a rare amino acid component of peptide antibiotics: Natural products and synthesis

• Darcy J. Atkinson,
• Briar J. Naysmith,
• Daniel P. Furkert and
• Margaret A. Brimble

Beilstein J. Org. Chem. 2016, 12, 2325–2342, doi:10.3762/bjoc.12.226

• investigations had revealed that the N- and O-sugars of the natural products were essential for potent antibacterial activity [35][38][39][41]. The most difficult challenge involved the preparation of the N-α-mannosyl-D-β-hydroxyenduracididine unit. N-Mannosylation was complicated by steric hindrance around 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

• [4], and were recently observed to inhibit cancer growth [5]. Because of the relevance of 2-deoxyglycosides, great efforts have been made in researching the assembly of oligosaccharides containing these sugars [6][7]. However, the absence of a neighbouring group at C2 causes poor stereoselectivity

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

• mutagenicity test; quaternary ammonium salt; Introduction Carbohydrates and alditols occur broadly in nature and possess many biological functions essential to living organisms. Sugars not only contribute as energetic substances, but also serve as building materials for fungi, microbes, plants, and animals

• located at the surface of the cell serve as potential targets for new drugs containing sugars [1][2][4]. Quaternary ammonium salts (QASs) constitute a class of organic compounds with a broad range of applications. A typical QAS consists of a positively charged nitrogen atom with four residues (aliphatic

• [22][23][24]. To overcome many problems associated with QASs, they were combined with sugars. We intended to obtain biologically active compounds – especially antibacterial and antifungal – with high biocompatibility and good biodegradation properties. Some examples of fused molecules containing QASs

Enantioselective carbenoid insertion into C(sp³)–H bonds

• J. V. Santiago and
• A. H. L. Machado

Beilstein J. Org. Chem. 2016, 12, 882–902, doi:10.3762/bjoc.12.87

• expensive than the use of other metals such as rhodium, copper and ruthenium, for example. Efforts should be directed toward the development of simpler ligands specially those based on inexpensive chiral building blocks like amino acids and sugars. The examples of works focused on copper-based catalysts are

Muraymycin nucleoside-peptide antibiotics: uridine-derived natural products as lead structures for the development of novel antibacterial agents

• Daniel Wiegmann,
• Stefan Koppermann,
• Marius Wirth,
• Giuliana Niro,
• Kristin Leyerer and
• Christian Ducho

Beilstein J. Org. Chem. 2016, 12, 769–795, doi:10.3762/bjoc.12.77

• ]. They contain a uridine moiety, two O-glycosidically linked sugars, the so-called tunicamine and a fatty acid moiety, which typically is terminally branched and unsaturated. Two closely related nucleoside antibiotics were isolated later on and named streptoviridins (isolated in 1975 from Streptomyces

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

• -2-azido-hexopyranoses have potential as synthons in oligosaccharide assembly. Keywords: amino sugars; cytotoxicity; fluorinated carbohydrates; fluorine; hexosamines; Introduction Derivatives of D-glucosamine (GlcN) and D-galactosamine (GalN) are essential amino sugar components of glycans in

• glycoproteins, glycolipids and proteoglycans. As such, they participate in functions performed by cell-surface glycans including cell adhesion and signaling [1]. Unnatural analogs of these amino sugars prepared by a selective replacement of a hydroxy group by fluorine have proved valuable tools to perturb

• glycan and glycosaminoglycan biosynthesis [2][3], to inhibit amino sugars processing enzymes [4][5], to probe interactions of amino sugars with their target enzymes and lectins [6][7], or to increase the hydrolytic stability of the glycosidic bond in amino sugar glycosides [8][9]. For example, acetylated