Die Polyuronsäuren der Braunalgen (Kohlenhydrate der Algen I)

Abstract

Hydrolysates of the cell walls of brown algae revealed on chromatography the presence of other uronic acids besides mannuronic acid which is the main constituent. Alginic acids were subjected to a prehydrolysis with 80% sulphuric acid for 14 hours at room temperature, followed by hydrolysis in 0.5% sulphuric acid at 100[degree]C for 6 hours. On chromatography guluronic acid anhydride was detected, and isolated, as well as mannuronic acid anhydride. The ratio of the two differed with the source of the sample and varied from 0.5 to 2.0. Tests showed that guluronic acid was not an artifact produced during the hydrolysis. Hydrolyses of whole algae showed the presence also of glucuronic acid, varying in amount from 1-10%) of the total uronic acids; but glucuronic acid was never found to be a constituent of the alginic acids. This is the first time that L-guluronic acid has been found as a natural product.