Chemical modification of maltose. IV. Synthesis of 4-O-.ALPHA.-D-altropyranosyl-D-glucopyranose.

Improved Synthesis of 1-O-Acyl-β-d-Glucopyranose Tetraacetates.

An improved synthesis of 1-O-acyl glucosyl esters that avoids the use of expensive Ag reagents as well as the hydrolysis of unstable glucosyl bromides is reported. Notably, β-configuration products were obtained exclusively in good yields.

Utilization and metabolism of [U-14C]4' galactosyllactose (O-beta-D-galactopyranosyl-(1----4)-O-beta-D-galactopyranosyl-(1----4)- D-glucopyranose) in rats.

O-beta-D-Galactopyranosyl-(1----4)-O-beta-D-galactopyranosyl- (1----4)-D-glucopyranose (designated as 4'GL) are produced from lactose with Cryptococcus laurentii OKN-4. Excretion and metabolism of 4'GL in rats were examined using a radioisotope technique. [U-14c]4'GL was synthesized from [U-14C]lactose by Cryptococcus laurentii OKN-4. The 14CO2 in expired air was counted after oral administrati...

Chemical modification of erythromycins. IV. Synthesis and biological properties of 6-O-methylerythromycin B.

6-O-Methylerythromycin B has been synthesized from erythromycin B via regioselective methylation of the 6-hydroxyl group in 71% overall yield. This compound shows in vitro antibacterial activity comparable to erythromycins A and B and exhibits superior in vivo activity with improved pharmacokinetic properties.

Antiferromagnetic 4-d O(4) Model

We study the phase diagram of the four dimensional O(4) model with first (β1) and second (β2) neighbor couplings, specially in the β2 < 0 region, where we find a line of transitions which seems to be second order. We also compute the critical exponents on this line at the point β1 = 0 (F4 lattice) by Finite Size Scaling techniques up to a lattice size of 24, being these exponents different from...

O - acetylation of G D : An Enigmatic Modification Regulating Apoptosis ?