Chrysogeside B, a natural cerebroside, was efficiently synthesized from commercial feedstocks. The bioassays showed that compounds 4, 5 and 6 exhibited enhanced biological activities compared Chrysogeside B. Further studies revealed that free hydroxyl groups and glycosidic bond have significant impact on the antimicrobial activities. The synthesis of Chrysogeside B and analogues designed to all...

A seven-step synthesis of orthogonally O-protected 2-deoxy-streptamine has been developed from readily available neomycin, with an overall yield of 28%. Key chemical transformations include a chemoselective glycosidic bond hydrolysis and two regioselective protective group manipulations involving acetylation and deacetylation. The synthetic route is amenable to scale-up for the production of mu...

Cyclodextrins are non-reducing cyclic glucose oligosaccharides resulting from the cyclomaltodextrin glucanotransferase (E.C. 2.4.1.19; CGTase) catalyzed degradation of starch. Their structures have been reviewed. There are three common cyclodextrins with 6, 7 or 8 D-glucopyranonsyl residues (α-, β-, and γ-cyclodextrin respectively) linked by α-1,4 glycosidic bonds. The glucose residues have the...

We describe the construction of peptide-carbohydrate conjugates, namely glycopeptides, capable of self-assembling in water. We found that disaccharide structures (epimer or glycosidic-bond geometry) appended to the glycopeptides have a noticeable effect on the hydrogel formation ability as well as the morphology of the self-assembled structures. The soft materials consisting of self-assembled s...

Negative-ion matrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spectra and tandem mass spectra of flavonoid mono-O-glycosides showed the irregular signals that were 1 and/or 2 Da smaller than the parent deprotonated molecules ([M - H](-)) and the sugar-unit lost fragment ions ([M - Sugar - H](-)). The 1 and/or 2 Da mass shifts are generated with the removing of a neutral h...

Atomic force microscope manipulations of single polysaccharide molecules have recently expanded conformational chemistry to include force-driven transitions between the chair and boat conformers of the pyranose ring structure. We now expand these observations to include chair inversion, a common phenomenon in the conformational chemistry of six-membered ring molecules. We demonstrate that by st...

X-ray crystallography, molecular modeling, and site-directed mutagenesis were used to delineate the catalytic mechanism of purine nucleoside phosphorylase (PNP). PNP catalyzes the reversible phosphorolysis of purine nucleosides to the corresponding purine base and ribose 1-phosphate using a substrate-assisted catalytic mechanism. The proposed transition state (TS) features an oxocarbenium ion t...

The syn-anti equilibrium about the glycosidic bond in adenosine and some related analogues was studied by means of 1H NMR spectroscopy, with the aid of several model analogues fixed in given conformations either by intramolecular bonding, or by introduction of a bulky substituent. A model unambiguously and exclusively in the syn conformation is 8- (alpha-hydroxyisopropyl) adenosine; while one f...

The glycosaminoglycan chondroitin sulfate is essential in human health and disease but exactly how sulfation dictates its 3D-structure at the atomic level is unclear. To address this, we have purified homogenous oligosaccharides of unsulfated chondroitin (with and without (15)N-enrichment) and analysed them by high-field NMR to make a comparison published chondroitin sulfate and hyaluronan 3D-s...

Our previous study revealed that the antioxidant activity of polysaccharide (coded as FGFP) extracted from Grifola frondosa by enzymolysis treatment was significantly superior than that (coded as GFP) extracted by boiling-water. In this study, one purified polysaccharide fractions (coded as FGFP-11) was obtained from FGFP by purified using DEAE-52 column and Sephacryl S-500HR column. Results in...