Antiviral activity of some natural and synthetic sugar analogues.

A number of natural and synthetic sugar analogues have been tested for their antiviral activity, using an influenza virus strain as a model. Hemagglutinating titres (HA) and cytopathic effect (CPE) were surveyed to estimate the virus production. It was found that introduction of the benzyl group into these sugars generally causes them to become antivirally active. Substitution with methyl, acetyl, uridyl and thiocyanyl groups or derivatization with azido, isopropylidene and benzylidene groups were without effect. All sugars containing the 2-deoxy-2-acetamido group were inactive.

Structural and dielectric properties of synthetic glycolipids in mixtures with water.

Three synthetically produced glycolipids, N-(beta-D-glucopyranosyl)-N-octadecyl-stearoylamide (OSGA), N-(beta-D-glucopyranosyl-N-octadecyl-oleoylamide (OOGA), N-(beta-D-galactopyranosyl)-N-octadecyl-lauroylamide (OLGA) have been studied in different mixtures with water by x-ray diffraction and dielectric measurements with microwaves at 9.4 GHz. The measurements were performed in the temperature range -50-70 degrees C. X-Ray diffraction revealed a direct L(beta') --> H( parallel) transition at 20 degrees C, 60 degrees C, and 45 degrees C depending on the glycolipid species but nearly not on the water content. The hexagonal phases are saturated at a water content of approximately 20 wt%. The lamellar phase absorbs even less water (< 10 wt%). The dielectric data show that in the H( parallel) phase the binding of water is stronger than in the L(beta') phase. In the temperature range below 0 degrees C, OSGA and OOGA show a "subzero transition" due to the freeze-out of water in a separate ice phase. This transition can be seen in an abrupt decrease of the dielectric function because the dielectric response of ice is much smaller at microwave frequencies. OLGA does not show the subzero transition but an additional transition, hexagonal --> distorted hexagonal at 60 degrees C.

[Synthesis of a disaccharide with antibiotic activity]. / Synthese eines Antibiotisch Aktiven Disaccharids.

The aminodisaccharide glycoside methyl 2,4-diamino-2,4-dideoxy-6-O-(2,6-diamino-2,6-dideoxy-alpha-D-glucopyranosyl)- beta-D-glucopyranoside (4), which exhibits a structural resemblance to neamine, was synthesized via the azido method. Starting from 6-O-acetyl-2-azido-3,4-di-O-benzyl-2-deoxy-alpha-D-glucopyranosyl bromide, the alpha-D-glycosylation of O-6 of methyl 2,4-diazido-3-O-benzyl-2,4-dideoxy-beta-D-glucopyranoside was accomplished stereoselectively at low temperatures in the presence of mercury bromide. Against some gram-negative test-organisms, the activity of 4 was found to be in the same range as neamine, but directed against different germs.