Properties of highly purified fucan.

Fucan was first isolated by Kylin from brown seaweed and named fucoidin by him (1). More recently fucan was isolated by Percival and Ross (2) from several Phaeophyceae. They considered it to be a polymeric salt of fucose monosulfate. However, their most highly purified preparation still contained approximately 5.6% sugars other than L-fucose and 3.3 ‘% uranic acid. A branched structure was suggested (3) for fucan with 1,2 links predominating (3, 4). The molecular weight of fucan determined by osmometric means was 133,000 f 20,000 (4). Anticoagulant active fractions were isolated from crude fucan in a yield of about 25% (5). Other fractions, although less active as anticoagulants, were potent lipemia clearers (6). All of these fractions contained a still unidentified sugar with chromatographic properties similar to but not identical with 3-O-methylfucose (5, 7). In the present work, highly purified fractions were prepared from crude fucan and their physical, chemical, and biological properties investigated. It is hoped that the study of physical behavior and the chemistry of these fucan fractions will contribute to a better understanding of the relation of biological activity to physical and chemical characteristics of fucan and other sulfated high polymers.