Inclusion of the insecticide fenitrothion in dimethylated-β-cyclodextrin: unusual guest disorder in the solid state and efficient retardation of the hydrolysis rate of the complexed guest in alkaline solution

• Dyanne L. Cruickshank,
• Natalia M. Rougier,
• Raquel V. Vico,
• Susan A. Bourne,
• Elba I. Buján,
• Mino R. Caira and
• Rita H. de Rossi

Beilstein J. Org. Chem. 2013, 9, 106–117, doi:10.3762/bjoc.9.14

• structure of fenitrothion (1). Representative TGA (top) and DSC (bottom) traces for DIMEB·1. The asymmetric unit in DIMEB•1 viewed along [010] (top) and [100] (bottom). H atoms are omitted for clarity. The host molecules in the asymmetric unit of DIMEB·1 with the labelling of both residues and atoms

An improved synthesis of a fluorophosphonate–polyethylene glycol–biotin probe and its use against competitive substrates

• Hao Xu,
• Hairat Sabit,
• Gordon L. Amidon and
• H. D. Hollis Showalter

Beilstein J. Org. Chem. 2013, 9, 89–96, doi:10.3762/bjoc.9.12

• the labelling efficiency of the FP–PEG–biotin probe 1 synthesized by our new route, we utilized it in the purification of four arbitrarily mixed proteins including bovine serum albumin (BSA), porcine carboxylesterase (pCES), nucleoside phosphorylase (NP), and trypsin (Figure 2A). Thus, the protein

• by the Cravatt group [21]. Kinetic study of FP probe labelling activity An incubation-time control study is the key toward successfully monitoring the competition between FP probe 1 and a reversible substrate with a high turnover rate. Hence, over a long incubation time, the substrate will be

• , blotted by streptavidin alkaline phosphatase, and visualized by incubation with ECF substrate. Kinetic study on FP labelling reactions. Caco-2 cell homogenates (1 mg/mL) were treated at room temperature with FP–PEG–biotin 1 (4 μM) for the indicated times, followed by the termination of reaction with 5

The Amadori rearrangement as glycoconjugation method: Synthesis of non-natural C-glycosyl type glycoconjugates

• Katharina Gallas,
• Gerit Pototschnig,
• Florian Adanitsch,
• Arnold E. Stütz and
• Tanja M. Wrodnigg

Beilstein J. Org. Chem. 2012, 8, 1619–1629, doi:10.3762/bjoc.8.185

• surfaces (glycosylated surfaces, e.g., “glyco-chips”, gold, polystyrene plates, glass, nanoparticles), or labelling and imaging of carbohydrates (fluorescence markers, biotin, photolabelling) [27][28]. Herein we describe the application of the Amadori rearrangement as a key step for the synthesis of non

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

• way, the synthetic sialosides can be easily conjugated to probes for biological evaluation or labelled for instance with UV-active tags. Biotinylation is a typical example of a commonly employed labelling technique [30] and has been extensively used for instance as a functionalization technique for

Synthesis of trifunctional cyclo-β-tripeptide templates

• Frank Stein,
• Tahir Mehmood,
• Tilman Plass,
• Javid H. Zaidi and
• Ulf Diederichsen

Beilstein J. Org. Chem. 2012, 8, 1576–1583, doi:10.3762/bjoc.8.180

• ]-cycloaddition under mild conditions. The template approach allows for the preparation of constructs that, e.g., combine biological activity, fluorescence labelling and cell-penetrating or cell-directing units in one molecule to be used for in vivo studies. The defined spatial organization of recognition units

Chemo-enzymatic modification of poly-N-acetyllactosamine (LacNAc) oligomers and N,N-diacetyllactosamine (LacDiNAc) based on galactose oxidase treatment

• Christiane E. Kupper,
• Ruben R. Rosencrantz,
• Birgit Henßen,
• Helena Pelantová,
• Stephan Thönes,
• Anna Drozdová,
• Vladimir Křen and
• Lothar Elling

Beilstein J. Org. Chem. 2012, 8, 712–725, doi:10.3762/bjoc.8.80

• use of galactose oxidase, which can be combined with different chemical modifications. Galactose oxidase is a copper-containing enzyme that catalyses the oxidation of the C6-hydroxyl group of nonreducing D-galactose residues [28][29]. Several subsequent modifications, such as site-specific labelling

• moieties. Labelling of 6-aldehydes of poly-LacNAc oligomers The 6-aldehyde products of poly-LacNAc oligomers 3a–c were further reacted with BACH (12) to incorporate a site-specific biotin label for subsequent detection of immobilised glycans. Conversion with 12 and subsequent reduction were performed

• of 10a showing the potential to produce terminally as well as internally oxidised and modified poly-LacNAc oligomers (11a). A: Labelling of poly-LacNAc oligomers 3a–c and 9a with biotin hydrazide derivative BACH (12) yielding the hydrazone products (13a–c and 14a); 13a–c and 14a were subsequently

Thiophene-based donor–acceptor co-oligomers by copper-catalyzed 1,3-dipolar cycloaddition

• Stefanie Potratz,
• Amaresh Mishra and
• Peter Bäuerle

Beilstein J. Org. Chem. 2012, 8, 683–692, doi:10.3762/bjoc.8.76

• polymers [21][22][23], and was used for DNA labelling [24][25], sensors [26][27], and metal chelates [28][29][30], due to the mild reaction conditions and compatibility with a variety of functional groups. However, the electronic conjugation through the resulting 1,2,3-triazole rings is weak due to poor

Syntheses and applications of furanyl-functionalised 2,2’:6’,2’’-terpyridines

• Jérôme Husson and
• Michael Knorr

Beilstein J. Org. Chem. 2012, 8, 379–389, doi:10.3762/bjoc.8.41

• complex 62, which bears a thiocyanato group at the para-position (Scheme 11). Because of the presence of a thiocyanato moiety in its structural motif and due to its fluorescence properties, compound 62 could be used potentially as a labelling agent for biomolecules. In fact, reaction between the reactive

• . In all the examples cited above, furanyl-functionalised terpyridines were selected because of their capability to absorb light and to transfer the excitation energy to the chelated lanthanide metal ion. This gives rise to a strong fluorescence, a feature which is required for labelling studies

• -functionalised tpys as potential biomolecule-labelling agents. Synthetic sequence envisioned for biomolecules labelling by click-chemistry. Influence of solvent on U/S ratio. Complexes obtained by direct oxidation of furanyl-functionalised tpys. GI50 (μg/ml) for terpyridines 12 and 13 compared to doxorubicin

Novel fatty acid methyl esters from the actinomycete Micromonospora aurantiaca

• Jeroen S. Dickschat,
• Hilke Bruns and
• Ramona Riclea

Beilstein J. Org. Chem. 2011, 7, 1697–1712, doi:10.3762/bjoc.7.200

• isopropyl group (m/z = 43 and m/z =143) shifted to m/z = 50 and m/z = 145 in agreement with the deuterium labelling of this portion of the molecule. The labelling was also introduced into the iso-odd FAMEs 102 and 103 (Figures S3C to S3F of Supporting Information File 1) and the higher homologue methyl 15

• -methylhexadecanoate (not shown). Methyl 15-methylhexadecanoate was only found during feeding of [2H10]leucine, similar to the formation of methyl 14-methylhexadecanoate found only during feeding of [2H10]isoleucine. Feeding of [2H8]valine Feeding of [2H8]valine resulted in the incorporation of the isotopic labelling

• genome of M. aurantiaca, but the pathway seemed not to be active under the experimental conditions, judged by the fact that no incorporation of [2H8]valine into the iso-odd FAMEs was observed. Furthermore, no uptake of labelling from [2H10]leucine into the iso-even FAMEs was found, which also rules out a

Synthesis of dye/fluorescent functionalized dendrons based on cyclotriphosphazene

• Aurélien Hameau,
• Sabine Fuchs,
• Régis Laurent,
• Jean-Pierre Majoral and
• Anne-Marie Caminade

Beilstein J. Org. Chem. 2011, 7, 1577–1583, doi:10.3762/bjoc.7.186

• interesting for elaboration of the original dendrimeric architectures [13][14], or for labelling materials or biological entities. In many cases, it is desirable to concentrate a maximum number of functional groups in a small compound (a small size is particularly important so as not to disturb biological

Meta-metallation of N,N-dimethylaniline: Contrasting direct sodium-mediated zincation with indirect sodiation-dialkylzinc co-complexation

• David R. Armstrong,
• Liam Balloch,
• Eva Hevia,
• Alan R. Kennedy,
• Robert E. Mulvey,
• Charles T. O'Hara and
• Stuart D. Robertson

Beilstein J. Org. Chem. 2011, 7, 1234–1248, doi:10.3762/bjoc.7.144

• ]+ calcd for C8H9I2N, 372.8; found, 373.8. Molecular structure of 2 with selective atom labelling. Hydrogen atoms and minor disorder components are omitted for clarity [20]. Molecular structure of 3 with selective atom labelling and thermal ellipsoids drawn at the 50% probability level. Hydrogen atoms are

• ). Molecular structure of 4 with selective atom labelling and thermal ellipsoids drawn at the 50% probability level. Hydrogen atoms and disordered component of TMEDA are omitted for clarity. Secondary contacts between sodium and the anilide rings are denoted by dashed lines. Only one of the

Isotopic labelling studies for a gold-catalysed skeletal rearrangement of alkynyl aziridines

• Paul W. Davies,
• Nicolas Martin and
• Neil Spencer

Beilstein J. Org. Chem. 2011, 7, 839–846, doi:10.3762/bjoc.7.96

• Paul W. Davies Nicolas Martin Neil Spencer School of Chemistry, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom 10.3762/bjoc.7.96 Abstract Isotopic labelling studies were performed to probe a proposed 1,2-aryl shift in the gold-catalysed cycloisomerisation of alkynyl

• aziridines into 2,4-disubstituted pyrroles. Two isotopomers of the expected skeletal rearrangement product were identified using 13C-labelling and led to a revised mechanism featuring two distinct skeletal rearrangements. The mechanistic proposal has been rationalised against the reaction of a range of 13C

• - and deuterium-labelled substrates. Keywords: 1,2-aryl shift; cycloisomerisation; gold; isotopic labelling; pyrrole; skeletal rearrangement; Introduction Gold-catalysed cycloisomerisation reactions have emerged as powerful methods to construct a diverse array of hetero- and carbocyclic motifs under

High chemoselectivity in the phenol synthesis

• Matthias Rudolph,
• Melissa Q. McCreery,
• Wolfgang Frey and
• A. Stephen K. Hashmi

Beilstein J. Org. Chem. 2011, 7, 794–801, doi:10.3762/bjoc.7.90

• , and these could even be trapped by Diels–Alder reactions. In addition, labelling studies were carried out and the electronic influence of substituents was investigated [21]. Computational studies as well as side-products produced in the reaction pointed towards intermediates A and B (Scheme 1) [22][23

Bioorthogonal metabolic glycoengineering of human larynx carcinoma (HEp-2) cells targeting sialic acid

• Arne Homann,
• Riaz-ul Qamar,
• Sevnur Serim,
• Petra Dersch and
• Jürgen Seibel

Beilstein J. Org. Chem. 2010, 6, No. 24, doi:10.3762/bjoc.6.24

• )neuraminic acid (Neu5Hex) into the cell-surface glycocalyx of a human larynx carcinoma cell line (HEp-2) and its fluorescence labelling by click chemistry. Keywords: bioorthogonal metabolic glycoengineering; click chemistry; sialic acid; Introduction The surface of eukaryotic cells is heavily covered with

• (Scheme 2). Metabolic glycoengineering of human larynx carcinoma (HEp-2) cells by incorporation of N-(1-oxohex-5-ynyl)neuraminic acid (Neu5Hex, 3) The metabolic labelling of human larynx carcinoma (HEp-2) cell surfaces was carried out in order to study and characterize the influence of sialic acid in cell

• ester, azido-fluorescein (14). For the metabolic labelling of eukaryotic cells, HEp-2 cells were incubated in Dulbecco's modified Eagle's medium (DMEM) with 10% fetal calf serum (FCS). At 80% confluence they were split into 6-well plates with DMEM containing the functionalized carbohydrates (Ac4GlcNAz

A convenient method for preparing rigid-core ionic liquid crystals

• Julien Fouchet,
• Laurent Douce,
• Benoît Heinrich,
• Richard Welter and
• Alain Louati

Beilstein J. Org. Chem. 2009, 5, No. 51, doi:10.3762/bjoc.5.51

• view of compound 1a with partial labelling. The closest molecules are represented (with lower opacity) when connected by CH-π and/or non classical H-bonds (black thin lines). The ellipsoids enclose 50% of the electronic density. Symmetry operators for equivalent positions: d = ±1+x, y, z; e = 1+x, 1+y

Themed series in organo- fluorine chemistry

• David O'Hagan

Beilstein J. Org. Chem. 2008, 4, No. 11, doi:10.3762/bjoc.4.11

• the area of medical imaging, positron emission tomography (PET) has undergone a step change in growth across all developing countries, with an exponential increase in the installation of PET cameras and cyclotrons to generate isotope for labelling ligands and diagnostic probes. 18F is an important