Picking structures out of a lineup Pharmaceutical research relies critically on determining the correct numerous complex molecules. When well-ordered crystals are not available for x-ray analysis, nuclear magnetic resonance (NMR) spectroscopy is most common structure-elucidation method. However, sometimes it hard to distinguish isomers with similar spectra. Liu et al. showcase protocol that combines computer modeling anisotropic NMR data acquired using gel-aligned samples. Because its...

The glycopeptides vancomycin and teicoplanin are clinically important antibiotics. carbohydrate portions of these molecules affect biological activity, there is great interest in developing efficient strategies to make derivatives. To this end, genes encoding four glycosyltransferases, GtfB, C, D, E, were subcloned from Amycolatopsis orientalis strains that produce chloroeremomycin (GtfB, C) or (GtfD, E) into Escherichia coli. After expression purification, each glycosyltransferase (Gtf) was...

Life-threatening allergies to peanuts and tree nuts can be revealed by detecting antibodies (IgEs) their allergens in patient serum. Herein, we compare several immunosensor-like methodologies for sensitive detection of a peptide sequence from the major peanut allergen, Arachis hypogaea 2 (Ara h2). The sensors feature synthetic layer IgE-binding epitope Ara h2 attached dense gold nanoparticle (AuNP) film on pyrolytic graphite (PG) electrode. AuNP−peptide sensor was used determine model...

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTRecognition and Stabilization of an α-Helical Peptide by a Synthetic ReceptorMark W. Peczuh, Andrew D. Hamilton, Jorge Sánchez-Quesada, Javier de Mendoza, Thomas Haack, Ernest GiraltView Author Information Department Chemistry, University Pittsburgh Pittsburgh, Pennsylvania 15260 Departmento Química Orgánica Universidad Autonoma Madrid Cantoblanco, 28049-Madrid, Spain Orgànica Universitat Barcelona, Martí i Franqués 1-11 08028-Barcelona, Cite...

The cardiac glycosides ouabain and digitoxin, established Na(+)/K(+) ATPase inhibitors, were found to inhibit MDA-MB-231 breast cancer cell migration through an unbiased chemical genetics screen for motility. acts both as ion-transporter a receptor glycosides. To delineate which function is related migration, structure-activity relationship (SAR) profiles of at the cellular (cell inhibition), molecular (Na(+)/K(+) atomic (computational docking) levels. SAR their analogs revealed similar...

Interacting with lectins, mannose can be mimicked seven-membered ring analogues but at the price of a substantial entropy penalty.

Because teicoplanin and vancomycin are the last line of defense for many bacterial infections, emergence resistance to glycopeptide antibiotics in enterococci streptococci has aroused concern. Despite their similarity terms structure mechanism action, induces expression genes that leads resistance, does not. We have used a combination chemical enzymatic methods produce sets analogues allow us consider whether aglycon, carbohydrate, or other parts these molecules stimulate VanB resistance....

We report the synthesis of methyl α-d-glycero-d-idoseptanoside (1) and β-d-glycero-d-guloseptanoside (2) characterization their preferred solution conformations by computational chemistry 1H NMR 3JH,H coupling constant analysis. Central to synthetic approach was epoxidation glucose-derived oxepine 3 using DMDO. Nucleophilic attack on resulting 1,2-anhydroseptanose NaOCH3 in CH3OH followed deprotection provided 1,2-trans diastereomers 1 2. The for determining low energy septanose began with a...

The first peptide-carbohydrate SPR imaging immunoarray aimed at diagnosing severity of peanut allergies is reported. SPRi chip features a peptide epitope protein allergen Ara h2, β-xylosyl glycoside, and anti-IgE antibody to achieve epitope-specific detection human IgEs sub-attomol levels.

The ability of the jack bean lectin concanavalin A (ConA) to bind seven membered ring (septanose) monosaccharides has been investigated by isothermal titration calorimetry (ITC) and saturation transfer difference (STD) NMR spectroscopy.

The recognition of tetraaspartate peptide (2) by tetra-guanidinium (1) in (a) water and (b) aqueous methanol (10% H2O/90% CH3OH) has been investigated. conformations the free its complex with 1 have characterized both solvent systems CD 2D NMR spectroscopies. Increased α-helicity as a result composition receptor binding are discussed. Control experiments show that stems from complementary electrostatic interactions, hydrogen bonding, matching surface topologies.

Reported here are details on the discovery of a phosphine-catalyzed isomerization hemiketals and subsequent reactions cyclic keto enol ether products. The new cycloisomerization complements previously reported amine-catalyzed process that gave oxepinones from same hemiketal starting materials. In absence functionality (R(2)) ether, rapid facile dimerization occurs, giving spiroketal When enone is substituted (i.e., R(2) = Ph), sufficiently stable so it can be isolated; then further reacted...

Spiroketals organize small molecule structures into well-defined, three-dimensional configurations that make them good ligands of proteins. We recently discovered a tandem cycloisomerization-dimerization reaction alkynyl hemiketals delivered polycyclic, enol-ether-containing spiroketals. Here we describe rearrangements those compounds, triggered by epoxidation their enol ethers completely remodel structures, essentially turning "inside out". Due to the high level substitution on carbon...

An S-phenyl α-d-idoseptanoside donor was used in the selective preparation of a series α-d-idoseptanosyl glycosides. Glycosylation methyl β-d-glycero-d-guloseptanoside acceptor with new constituted first synthesis septanose disaccharide.

The facial selectivity in the DMDO epoxidation of carbohydrate-based oxepines derived from glucose, galactose, and mannose has been determined by product analysis density functional theory (DFT, B3LYP/6-31+G**//B3LYP/6-31G*) calculations. Oxepines 3 4, d-galactose d-mannose, largely favor α- over β-epoxidation. results reported here, along with selectivities DMDO-mediated d-xylose-based oxepine 1 d-glucose-based 2 5 earlier, support a model which electronic effects, guided stereochemistry...

DMDO epoxidation of carbohydrate fused [13]-macro-dilactones was found to be highly diastereoselective. Facial selectivity the depended on identity carbohydrate. Gluco-configured macro-dilactones gave R, R epoxide, whereas galacto- configuration S, S epoxide. The epoxide stereochemisty confirmed by independent syntheses dimethyl 4 R,5R-epoxyoctanedioate via Shi E-oct-4-enedioate and transesterification derived from gluco-[13]-macro-dilactone. We demonstrate diastereoselectivity in alkene...

Peanut allergy can be life-threatening and is mediated by allergen-specific immunoglobulin E (IgE) antibodies. Investigation of IgE antibody binding to allergenic epitopes identify specific interactions underlying the allergic response. Here, we report a surface plasmon resonance imaging (SPRi) immunoassay for differentiating antibodies epitope-resolved detection. were first captured magnetic beads bearing ϵ-chain-specific then introduced into an SPRi array immobilized with from major peanut...

Ring-expanded 2-N-acetylamino sugar analogs of d-glucose, d-galactose, and d-mannose have been prepared by a new synthetic route. Aspects the highly substituted α-amino aldehyde intermediates made them central to approach. First, they were accessed via diastereoselective addition vinyl Grignard onto protected glycosyl amines. Also, sterics bis-protected amine favored formation only one glycoside anomer. The analogues reported here should prove useful in development tools investigate role...

Contrary to previous reports in the literature, reaction of polyhydric alcohols such as sorbitol or mannitol gives good yields tetrahydroxyoxepane derivative presence an acid catalyst, refluxing toluene, with complete retention stereochemistry.