O-polysaccharides were isolated from the lipopolysaccharides of Escherichia coli O40 and Shigella dysenteriae type 9 and studied by chemical analyses along with (1)H and (13)C NMR spectroscopy. The following new structure of the O-polysaccharide of E. coli O40 was established: -->2)-beta-D-Galp-(1-->4)-beta-D-Manp-(1-->4)-alpha-D-Galp-(1-->3)-beta-D-GlcpNAc-(1--> TheO-polysaccharide structure o...

A novel continuous flow process for selective hydrogenation of α, β-unsaturated aldehyde (cinnamaldehyde, CAL) to the unsaturated alcohol (cinnamyl alcohol, COL) has been reported in a tube reactor coated with a Pt/SiO2 catalyst. A 90% selectivity towards the unsaturated alcohol was obtained at the aldehyde conversion of 98.8%. This is a six-fold improvement in the selectivity compared to a bat...

Photochemical excitation of a diaryldiazomethane with an ortho-acetal both in solution and in crystals led to products that originate from the expected diarylcarbene and form an intramolecular oxonium ylide. While crystals strongly favored the formation of a benzocyclobutane by intramolecular hydrogen abstraction in the triplet carbene, reactions in benzene led exclusively to products that deri...

Acetaldehyde diethyl acetal (herein called acetal) is an important pollutant of anhydrous ethanol. Isobaric vapor–liquid equilibrium (VLE) ethanol–acetal binary system was measured using a vapor condensate and liquid circulation VLE still. The experimental data were correlated with Wilson, nonrandom two-liquid (NRTL), universal quasichemical (UNIQUAC) activity coefficient models, which found su...

A synthetic strategy for the modeling construction of the highly bridged azatetracyclic ABEF ring system of numerous lycoctonine-type C19-diterpenoid alkaloids bearing a characteristic oxygenated quaternary center at C-7 has been successfully developed. The tetracyclic core was constructed rapidly from a readily prepared 6,7-bicyclic AB ring precursor through a 13-step sequence via an advanced ...

The reaction of 2-naphthol and also para-substituted phenols with glyoxal in presence of choline chloride: 2 ZnCl2 [ChCl: 2ZnCl2], a deep eutectic solvent (DES), as a green catalyst was studied. The amount of catalyst, solvent type, temperature, and time on the yield of reaction were investigated. It was found that the optimal condition included 10% mol ratio of catalyst (mol percentage of DES ...

Dimers and higher order oligomers, whether in the gas or particle phase, can affect important atmospheric processes such as new particle formation, and gas-particle partitioning. In this study, the thermodynamics of dimer formation from various oxidation products of α-pinene ozonolysis are investigated using a combination of Monte Carlo configuration sampling, semi-empirical and density functio...

A spur gear is one of the most common forms precision cylindrical gear. In industry, reducing weight gears while keeping their useful properties has become an even more pressing challenge. As a result, investigators have made many attempts to reduce gears. Despite these efforts, problem still requires research. This study presented gear's modeling and finite element analysis using different mat...