Smart molecules for imaging, sensing and health (SMITH)

• Bradley D. Smith

Beilstein J. Org. Chem. 2015, 11, 2540–2548, doi:10.3762/bjoc.11.274

• inexperienced group, we started out looking at synthetic transport carriers for biomolecules such as sugars, nucleotides, amino acids, and catecholamines [5] (Scheme 2). Later on we started looking at chloride transport and we enjoyed a very productive collaboration with the British group of A. P. Davis to

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

• formation and ring opening as well as reversion of the hydroxy group on the sugar ring. Jeong and co-workers [38][39][40] synthesized fluorine-substituted ribofuranose but isolation required a challenging separation. Therefore, the synthetic challenges for preparing 3’-fluorine modified sugars 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

• esterifications of sugars and steroids, using acylating agents different from simple aliphatic acids [7][8][9]. Specifically, years ago Dordick and coworkers proposed the so-called ‘combinatorial biocatalysis’ as an approach to easily produce small libraries of derivatives of bioactive natural compounds using a

Structure and conformational analysis of spiroketals from 6-O-methyl-9(E)-hydroxyiminoerythronolide A

• Ana Čikoš,
• Irena Ćaleta,
• Dinko Žiher,
• Mark B. Vine,
• Ivaylo J. Elenkov,
• Marko Dukši,
• Dubravka Gembarovski,
• Marina Ilijaš,
• Snježana Dragojević,
• Ivica Malnar and
• Sulejman Alihodžić

Beilstein J. Org. Chem. 2015, 11, 1447–1457, doi:10.3762/bjoc.11.157

• ; spiroketal; Introduction Macrolide antibiotics are natural or semi-synthetic products of polyketide origin, containing one or more desoxy sugars attached to a macrocyclic lactone aglycon. This large and structurally diverse category of compounds has traditionally been divided into classes based on the

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

• ligation method for conjugation of unprotected sugars and amines, when applied to suitable sugar substrates. Herein, we evaluated this synthetic method for the preparation of ligands for the α-D-mannose-specific type 1-fimbrial bacterial lectin FimH. The synthesis of heptopyranose 8 as a starting material

N-Alkyl derivatives of diosgenyl 2-amino-2-deoxy-β-D-glucopyranoside; synthesis and antimicrobial activity

• Agata Walczewska,
• Daria Grzywacz,
• Dorota Bednarczyk,
• Małgorzata Dawgul,
• Andrzej Nowacki,
• Wojciech Kamysz,
• Beata Liberek and
• Henryk Myszka

Beilstein J. Org. Chem. 2015, 11, 869–874, doi:10.3762/bjoc.11.97

• diosgenin. Very often this D-glucopyranose is substituted with α-L-rhamnopyranose at 2-OH and other sugars at 4-OH. The change of D-glucopyranose into 2-amino-2-deoxy-D-glucopyranose provides diosgenyl 2-amino-2-deoxy-β-D-glucopyranoside (7), a synthetic saponin, first reported by us [39]. It was also

• summarized and presented. We have studied different glycosyl donors, different amine group protections, different solvents and promoters to find the best way to obtain 7. The presented compilation is informative for all those interested in the glycosidation of 2-amino-2-deoxy sugars. Results and Discussion

Peptide–polymer ligands for a tandem WW-domain, an adaptive multivalent protein–protein interaction: lessons on the thermodynamic fitness of flexible ligands

• Katharina Koschek,
• Vedat Durmaz,
• Oxana Krylova,
• Marek Wieczorek,
• Shilpi Gupta,
• Martin Richter,
• Alexander Bujotzek,
• Christina Fischer,
• Rainer Haag,
• Christian Freund,
• Marcus Weber and
• Jörg Rademann

Beilstein J. Org. Chem. 2015, 11, 837–847, doi:10.3762/bjoc.11.93

• with an average MW of either 10 kDa (for Dex-1 and Dex-2) or 50 kDa (for Dex-3), both with a polydispersity index of 1.5. Under basic conditions the linear polysaccharide was alkylated with acrylamide selectively in the 2-positions of the sugars. The resulting 2-O-carboxyethyl dextran (2-O-CE-dextran

Orthogonal dual-modification of proteins for the engineering of multivalent protein scaffolds

• Michaela Mühlberg,
• Michael G. Hoesl,
• Christian Kuehne,
• Jens Dernedde,
• Nediljko Budisa and
• Christian P. R. Hackenberger

Beilstein J. Org. Chem. 2015, 11, 784–791, doi:10.3762/bjoc.11.88

• galactose 2 (see Supporting Information File 1). Lower concentrations of CuSO4 led to higher degrees of functionalization with 3–4 (10 mol %, Gal-3) galactose units, whereas higher amounts of Cu2+ led to lower degrees of functionalization with 1–2 clicked sugars (30 mol %, Gal-1). Further evidence for

Probing multivalency in ligand–receptor-mediated adhesion of soft, biomimetic interfaces

• Stephan Schmidt,
• Hanqing Wang,
• Daniel Pussak,
• Simone Mosca and
• Laura Hartmann

Beilstein J. Org. Chem. 2015, 11, 720–729, doi:10.3762/bjoc.11.82

• generally low affinity between sugars and receptors and possibly also by the high flexibility of the polymeric mannose linkers [9]. High molecular flexibility causes a high degree of conformational entropy that negatively affects complex formation between ligands and receptors [23]. Also the design of the

Synthesis of 1,2-cis-2-C-branched aryl-C-glucosides via desulfurization of carbohydrate based hemithioacetals

• Henok H. Kinfe,
• Fanuel M. Mebrahtu,
• Mandlenkosi M. Manana,
• Kagiso Madumo and
• Mokela S. Sokamisa

Beilstein J. Org. Chem. 2015, 11, 583–588, doi:10.3762/bjoc.11.64

• defensive low molecular weight thiol [7]. 2-C-acetamide and 2-C-acetonyl carbohydrate derivatives have also been reported to serve as inhibitors of the biosynthesis of lipids [8][9] and cell surface engineering [10], respectively. The main synthetic protocols for the synthesis of 2-C-branched sugars involve

• the regioselective ring opening of 1,2-cyclopropanated carbohydrates and the radical addition reaction of glycals [11][12][13][14][15]. Although the synthetic methodologies developed for the synthesis of C-glycosides and 2-C-branched sugars are extensively studied, the synthesis of 1,2-cis-2-C

• starting material. Compared to the previously reported protocols, especially via opening of 1,2-cyclopropanated sugars [30][31], the current strategy is superior in stereoselectivity and amenability of the 2-C-branch for further manipulation. The synthetic application of the 2-carbaldehyde of the aryl-C

3α,5α-Cyclocholestan-6β-yl ethers as donors of the cholesterol moiety for the electrochemical synthesis of cholesterol glycoconjugates

• Aneta M. Tomkiel,
• Adam Biedrzycki,
• Jolanta Płoszyńska,
• Dorota Naróg,
• Andrzej Sobkowiak and
• Jacek W. Morzycki

Beilstein J. Org. Chem. 2015, 11, 162–168, doi:10.3762/bjoc.11.16

• leads to sterol glycoconjugates. Initially, the reaction of cholesterol (1) with various sugars was studied. During anodic oxidation of cholesterol in dichloromethane (the choice of solvent is crucial as the reaction course may be different in other solvents) [1], splitting of the carbon–oxygen bond in

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

• group. When the galactosyl acceptor is water, a galactose molecule is produced and the hydrolysis of lactose occurs. However, this transfer can be performed onto other acceptors such as sugars, yielding oligosaccharides through a transglycosylation mechanism [5]. Hydrogels are 3D networks capable of

Enantioselective synthesis of polyhydroxyindolizidinone and quinolizidinone derivatives from a common precursor

• Nemai Saha and
• Shital K. Chattopadhyay

Beilstein J. Org. Chem. 2014, 10, 3104–3110, doi:10.3762/bjoc.10.327

• complement to those existing in the literature. The prepared compounds may also prove to be biologically important. Selected polyhydroxyindolizidine and quinolizidines of importance. Target bicyclic imino sugars Ia and Ib from a common intermediate IV. Selected nOe correlations (A) and coupling constants (B

Synthesis of divalent ligands of β-thio- and β-N-galactopyranosides and related lactosides and their evaluation as substrates and inhibitors of Trypanosoma cruzi trans-sialidase

• María Emilia Cano,
• Rosalía Agusti,
• Alejandro J. Cagnoni,
• María Florencia Tesoriero,
• José Kovensky,
• María Laura Uhrig and
• Rosa M. de Lederkremer

Beilstein J. Org. Chem. 2014, 10, 3073–3086, doi:10.3762/bjoc.10.324

• [32][33]. In the present work, we selected thioglycosidic and N-glycosidic bonds to link the acceptor sugars to a platform by click chemistry, taking into consideration that they are highly resistant to enzymatic hydrolysis [34][35]. We have previously described the synthesis of multivalent β

Preparation and evaluation of cyclodextrin polypseudorotaxane with PEGylated liposome as a sustained release drug carrier

• Kayoko Hayashida,
• Taishi Higashi,
• Daichi Kono,
• Keiichi Motoyama,
• Koki Wada and
• Hidetoshi Arima

Beilstein J. Org. Chem. 2014, 10, 2756–2764, doi:10.3762/bjoc.10.292

• various targeting-ligands such as antibodies, sugars and folic acid to LPs [30][31][32]. Recently, stimulus responsive LPs such as bubble LPs, pH responsive LPs and thermoresponsive LPs have been developed as smart drug carriers [33][34][35]. PEGylated LP (PEG-LP) is one of the most popular LP products

Gold(I)-catalysed synthesis of a furan analogue of thiamine pyrophosphate

• Amjid Iqbal,
• El-Habib Sahraoui and
• Finian J. Leeper

Beilstein J. Org. Chem. 2014, 10, 2580–2585, doi:10.3762/bjoc.10.270

• ., pyruvate dehydrogenase, pyruvate decarboxylase), the formation of amino acid precursors (acetohydroxy acid synthase), and ketol transfer between sugars (transketolase) [1]. One common feature of ThDP-dependent enzymes is to catalyse the cleavage and formation of bonds adjacent to the carbon of a carbonyl

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

• Markus Norrlinger Thomas Ziegler Institute of Organic Chemistry, University of Tuebingen, Auf der Morgenstelle 18, 72076 Tuebingen, Germany 10.3762/bjoc.10.256 Abstract New aromatic glycoconjugate building blocks based on the trifunctional 3-aminomethyl-5-aminobenzoic acid backbone and sugars

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

• . In this way, almost quantitative recovery of the activated sugars 11–13 was achieved. Active esters 11–13 were then coupled with the amino groups of the protein in sodium phosphate buffer (100 mM NaPi, pH 7.2) at room temperature for 24 h (Scheme 3). The glycoconjugates 14–16 were purified from the

• latter analytical technique enabled determination of the saccharide/protein molar ratio (saccharide loading). The characteristics of the prepared glycoconjugates are summarized in Table 1. A moderate loading (5–7 sugars/protein) was obtained in compounds 14–16 in respect to conjugates prepared by the

Multivalent glycosystems for nanoscience

• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2014, 10, 2345–2347, doi:10.3762/bjoc.10.244

• this field of research. Now, a third “sweet” Thematic Series is presented in which the borderline between Alice’s Wonderland and real-life applications of carbohydrates has been deliberately crossed. The structural world of natural sugars has been extended towards artificial carbohydrate architectures

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

• fact that it can be orthogonal to the azide–alkyne cycloaddition [22][26][27] which allows dual labeling of two different sugars within one experiment [19][21][23][24]. Among the dienophiles mentioned above, strained cyclopropenes have the highest reaction rates for DAinv reactions with tetrazines and

• sugars 1 and 2 we neutralized the corresponding hexosamine hydrochlorides 5 and 6 with sodium methoxide and coupled them to the activated cyclopropene 7 (Scheme 2), the synthesis of which we reported previously [24]. Subsequent acetylation of the carbamates 8 and 9 gave Ac4GlcNCyoc (1) and Ac4GalNCyoc (2

• ], followed by labeling with streptavidin–AlexaFluor647 (streptavidin–AF647) (Scheme 3). With all three sugars staining of the plasma membrane was detected by confocal laser scanning microscopy of living cells (Figure 2A, B, C). Only the solvent control did not show any membrane staining (Figure 2D, for

Indium-mediated allylation in carbohydrate synthesis: A short and efficient approach towards higher 2-acetamido-2-deoxy sugars

• Christopher Albler,
• Ralph Hollaus,
• Hanspeter Kählig and
• Walther Schmid

Beilstein J. Org. Chem. 2014, 10, 2230–2234, doi:10.3762/bjoc.10.231

Reaction of selected carbohydrate aldehydes with benzylmagnesium halides: benzyl versus o-tolyl rearrangement

• Maroš Bella,
• Bohumil Steiner,
• Vratislav Langer and
• Miroslav Koóš

Beilstein J. Org. Chem. 2014, 10, 1942–1950, doi:10.3762/bjoc.10.202

• simple alkyl or aryl branched-chain sugars involves the addition of Grignard reagents. In this regard, a wide variety of Grignard reagents have been added to the free or masked (as hemiacetal) carbonyl functionalities present in the molecule of a suitable fully O-protected saccharide, thereby making

• ketones affording the corresponding hydantoins (precursors of amino acids) via the Bucherer–Bergs reaction in the next step, which were finally transformed into sugar amino acids (precursors of biologicaly active iminosugars). Thus, using methylmagnesium iodide, some alanine-branched sugars were obtained

Synthesis of a bifunctional cytidine derivative and its conjugation to RNA for in vitro selection of a cytidine deaminase ribozyme

• Nico Rublack and
• Sabine Müller

Beilstein J. Org. Chem. 2014, 10, 1906–1913, doi:10.3762/bjoc.10.198

• RNA catalysts that support an aldol reaction between an aldehyde and a ketone, relevant to the synthesis of sugars [6], or the linkage of ribose to nucleobases to generate nucleotides [7]. Such ribozymes are seen as important functional entities underscoring the RNA world theory, where ribonucleic

Multicomponent reactions in nucleoside chemistry

• Mariola Koszytkowska-Stawińska and
• Włodzimierz Buchowicz

Beilstein J. Org. Chem. 2014, 10, 1706–1732, doi:10.3762/bjoc.10.179

• system (Scheme 27) [98][99]. Attempts to replace the aldehyde 73a with its 3,4,6-hydroxylated counterpart failed to give the expected product [99]. Dwivedi et al. showed that the isopropylidene-protected sugars 75 reacted efficiently with urea (or thiourea) and 1,3-dicarbonyl compounds in diethylene

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

• ; Introduction Anhydro sugars are formed by the intramolecular elimination of a water molecule, with the simultaneous formation of a new heterocyclic ring of different size. They are valuable intermediates not only in carbohydrate synthesis, but also as starting materials for other natural and non-natural

• complex products and bioactive compounds. Among the glycosans, the anhydro sugars involving the anomeric center in the ring formation, the 1,6-anhydro sugars are the most common and useful building blocks [1][2]. They can play a role in synthetic methodologies aiming at the obtainment of regioselectively

• functionalized sugars in a few steps, which could give easy access to convenient glycosyl donors and acceptors [3]. Some sugars, for example galactose, can afford not only the pyranosic derivative 1 but also the furanosic 1,6-anhydro derivative 2, both of which may be equipped with [3.2.1] bicyclic skeletons