The solution conformation of the disaccharide of avermectin B1a was examined by combining NMR data with theoretical conformational energy calculations. Carbon and proton resonances were assigned unambiguously using high-field, high-resolution 2D NMR correlation spectroscopy. 3JHH coupling constants were determined at 600 MHz. The minimum-energy conformation was attained through an extended hard...

The unusual stability of bis- and tris-peroxides contradicts the conventional wisdom - some of them can melt without decomposition at temperatures exceeding 100 °C. In this work, we disclose a stabilizing stereoelectronic effect that two peroxide groups can exert on each other. This stabilization originates from strong anomeric nO → σ*CO interactions that are absent in mono-peroxides but reintr...

Crystalline samples of D-xylose have been vaporized by laser ablation and probed in the gas phase using Fourier transform microwave spectroscopy. The rotational spectrum revealed the existence of two α-D-xylopyranose conformers stabilized by the anomeric effect and cooperative hydrogen bond networks. The experiment spectroscopically tracked fine structural changes upon clockwise and countercloc...

Spatial orientation of carbohydrates is a meaningful parameter in carbohydrate recognition processes. To vary orientation of sugars with temporal and spatial resolution, photosensitive glycoconjugates with favorable photochromic properties appear to be opportune. Here, a series of azobenzene glycosides were synthesized, employing glycoside synthesis and Mills reaction, to allow "switching" of c...

The subject paper presented the ®rst confor-mational analysis of the anomeric e€ect within the context of molecular orbital theory, discussed the utility of Fourier decomposition of a torsional coordinate as a method for analyzing disparate electronic in¯uences on that coordinate, and helped settle debate on the nature of anomeric stabilization. Sugars are the stepchildren of the biomonomer fam...

Glycolipid antigens recognized by αβ T-cell receptors (TCRs) drive the activation of invariant natural killer T (iNKT) cells, a specialized subset of innate T lymphocytes. Glycolipids with α-linked anomeric carbohydrates have been identified as potent microbial lipid antigens for iNKT cells, and their unusual α-anomeric linkage has been thought to define a "foreign" lipid antigen motif. However...

When using benzyl ethers as permanent protecting groups in oligosaccharide synthesis selective oxidative debenzylation with NaBrO(3) + Na(2)S(2)O(4) under biphasic conditions is efficient and compatible with anomeric azides and many other functions.

Acid-base catalyzed glycosyl donor and then glycosyl acceptor activation with phenylboron difluoride or diphenylboron fluoride permits hydrogen bond mediated intramolecular S(N)2-type glycosidation in generally high anomeric selectivity.

α-Nitrophenyl derivatives of glycosides are convenient substrates used to detect and characterize α-N-acetylgalactosaminidase. A new procedure combining chemical biocatalytic steps was developed prepare 4-nitrophenyl-2-acetamido-2-deoxy-α-D-galactopyranoside (4NP-α-GalNAc). The α-anomer prepared through synthesis an anomeric mixture followed by selective removal the β-anomer using specific enzy...