Water-soluble polysaccharides of some far-eastern brown seaweeds. Distribution, structure, and their dependence on the developmental conditions

Abstract

The comparative study of the content and structure characteristics of water-soluble polysaccharides, laminarans and fucoidans, of some wide-spread in the far-eastern seas brown seaweeds, collected in different places, at various stages of development, and in different seasons was conducted. The contents and structures of these glycans from Laminaria cichorioides vary depending on the season of yield and seaweed's age. The mature L. cichorioides was shown to be the richest source of both polysaccharides with almost equal of their contents (ca. 10%). The content and structure of both laminarans and fucoidans in Fucus evanescens were shown to vary considerably with the place of growth. The samples of Laminaria japonica were taken from two subspecies with 1-year and 2-year cycles of the development. Both subspecies were revealed to have a little of fucoidan (about 5%) and negligible quantity of laminaran (less than 1%). Fucoidans isolated from the mature L. cichorioides algae are practically pure high-sulfated α- l-fucans. Fucose was the predominant monosaccharide in fucoidans from F. evanescens and L. japonica; however, fucoidans of F. evanescens were enriched with xylose while those from L. japonica were enriched with galactose. The structure of highly sulfated α- l-fucan from mature L. cichorioides having the strongest activity towards APC was studied in detail.