THE DEGRADATION OF GLYCOSPHINGOLIPIDS BY AIR

Exposure of glycosphingolipids to air irreversibly destroys the integr ity of these lipids within a few hours. It was established that among the natural constituents of air, ozone, at commonly observed day-time levels, is responsible for the observed degradation As one product of the reaction of glycosphingolipids with air, an aldehydic fragment con taining the carbohydrate moiety was identified. This aldehydic fragmen t was identical to the one obtained by classical glycosphingolipid ozo nolysis. Identical with the latter, the air-induced product is further fragmented by mild alkali treatment with concomitant liberation of th e free reducing oligosaccharide. As a consequence of the alteration of glycosphingolipids by air, it was shown that the accuracy of methods of analysis of these glycoconjugates that depend on their physico-chem ical integrity, e.g., by tie-immune overlay, is severely influenced by their prior exposure to the atmosphere.