Production of keto-disaccharides from aldo-disaccharides in subcritical aqueous ethanol

Conformational kinetics of disaccharides in aqueous solutions.

Between 100 kHz and 2 GHz ultrasonic attenuation spectra of disaccharides in water have been measured at 25 degrees C. Some additional measurements have been performed at different temperatures between 10 and 35 degrees C and as a function of saccharide concentration c (0.5 mol/l</=c</=1.8 mol/l). The analytical description of the spectra in terms of relaxation spectral functions revealed four ...

Production of rare sugars from common sugars in subcritical aqueous ethanol.

A new isomerization reaction was developed to synthesize rare ketoses. D-tagatose, D-xylulose, and D-ribulose were obtained in the maximum yields of 24%, 38%, and 40%, respectively, from the corresponding aldoses, D-galactose, D-xylose, and D-ribose, by treating the aldoses with 80% (v/v) subcritical aqueous ethanol at 180°C. The maximum productivity of D-tagatose was ca. 80 g/(Lh). Increasing ...

Disaccharides and cystic fibrosis of the pancreas.

Disaccharide intolerance has been described in cystic fibrosis of the pancreas (Cozetto, 1963; Nordio et al., 1966; Sunshine and Kretchmer, 1964). However, the relation between clinical signs and symptoms, and biochemical investigations is not clear. For instance, Cozetto (1963) reported isolated depressed lactase activity in an otherwise normal mucosa, but gave no clear clinical evidence in su...

The Fermentation of Disaccharides by Streptococcus thermophilus.

Synthesis and Reactivity of 4′-Deoxypentenosyl Disaccharides

4-Deoxypentenosides (4-DPs) are versatile synthons for rare or higher-order pyranosides, and they provide an entry for structural diversification at the C5 position. Previous studies have shown that 4-DPs undergo stereocontrolled DMDO oxidation; subsequent epoxide ring-openings with various nucleophiles can proceed with both anti or syn selectivity. Here, we report the synthesis of α- and β-lin...