Six different metal-ion complexes of D-glucobenzothiazoline were synthesized and characterized by analytical and spectral techniques. Formation of different types of species (ML and ML(2)) were observed with Cu(2+), Ag(+), Cd(2+), Hg(2+), and Zn(2+) ions. Existence of an anomeric mixture in the case of the Cu(2+) complex is identified from the EPR spectra, and the results were further supported...

A new series of monosaccharide-based glycolipids devoid of phosphate groups and with two lipid chains were rationally designed by varying the lipid chain lengths and saccharide structure of a α-GalCer-derived lead compound (CCL-34) that is a potent TLR4 agonist. The NF-κB activity of a 60-membered galactosyl serine-based synthetic library containing compounds with various lipid chain lengths wa...

The effect of N-aglycones at C1’ on the drive of two-state north (N (C3’-endo-C2’-exo)) * south ( S (C2’endo-C3’-exo)) pseudorotational equilibrium in 8-D-ribofuranosyl-N-nucleosides consists of two counteracting contributions from (i) the anomeric effect (stereoelectronic interactions between furanose 04’ and the nucleobase nitrogen at Cl’), which places the aglycone in the pseudoaxial orienta...

The HF/6-31G level of theory was used to calculate relaxed potential energy surfaces for 12 analogs of disaccharides. The analogs were made by replacing glucose with tetrahydropyran and fructose with 2-methyltetrahydrofuran. Molecules had zero, one or two anomeric carbon atoms, and di-axial, axial-equatorial, and di-equatorial linkages. Despite the absence of hydroxyl groups, the surfaces accou...

The proportions of axial anomers of various glucosylamines (2) and their conjugate acids were determined by 1H NMR. The change upon N-protonation is small and can be accounted for by steric effects, without any "reverse anomeric effect." To test whether N-protonation changes the steric bulk of an imidazolyl group, ring-inversion equilibria of cis-N-(4-alkylcyclohexyl)imidazoles (3c, 4c) and of ...

[2+2] Cycloadditions of methylene exo-glycal derivatives with chlorosulfonyl isocyanate and dichloroketene were studied in detail, investigating the effect carbohydrate moiety, protecting groups as well reaction temperature on yields transformations. These reactions gave new anomeric spiro-β-lactam spiro-cyclobutanone derivatives, whose structure was established by 1D 2D NMR MS experiments. The...

The aim of this work is to optimize the oxidation resistance of ZrB2-SiC-based composites with different additives. Effect of nine factors including SiC, Cf, MoSi2, HfB2 and ZrC contents, milling time of Cf (M.t) and SPS parameters such as temperature, time and pressure on oxidation resistance in four levels was investigated. Taguchi design was applied to explore effective parameters for ...

The determination of the energetics of the temperature-dependent two-state N $ S pseudorotational equilibrium through 3JHH analysis in 36 nucleos(t)ides and 3 abasic sugars has allowed us for the first time to quantify the strength of various nucleobase-dependent anomeric and gauche effects, and how their interplay finally steers the sugar conformation. The plots of the pDdependent thermodynami...

The biological significance of glycoconjugates has stimulated a great synthetic activity in the synthesis of these structurally demanding compounds. These efforts were in the beginning mainly concentrated on improvements of the well-known KOENIGS-KNORR METHOD providing finally a very valuable methodology for glycoconjugate synthesis. However, due to several, mainly inherent disadvantages other ...