Water-soluble polysaccharides of some brown algae of the Russian Far-East. Structure and biological action of low-molecular mass polyuronans

The contents and structural characteristics of water-soluble polysaccharides such as polyuronans, fucoidans and laminarans dependent on species, age of algae and the year of collection were studied for four species of brown algae - Alaria fistulosa, A. marginata, Fucus evanescens and Laminaria cichorioides, widespread on the Russian Far-East. The mature L. cichorioides was shown to be the richest source of both laminarans and fucoidans, F evanescens - fucoidans. However, the Alaria species and young age algae F evanescens contained practically polyuronans only. Alaria marginata and A. fistulosa were revealed to have a little of fucoidan and negligible quantity of laminaran (less than 1%). Contents of water-soluble polyuronans in A. fistulosa were approximately 2 times more, than in A. marginata. Water-soluble polyuronans of these seaweeds are represented by polymannuronans (Mm about 40 kDa). It was shown, that the young age algae E evanescens contains the water-soluble low-molecular mass mannuronans along with the high-molecular mass laminarans. Stimulating action of polyuronans on the sea urchin developing embryos was revealed. (c) 2005 Elsevier B.V. All rights reserved.