Durvillea Fucoidan is a fucan sulphate occurring in brown marine algae (Phaeophyta) typically Durvillea antarctica, and has been shown to have anti-coagulant activity. Other therapeutic indications are reported in the literature. The fucose content of this fucan is approx. 27.9% and it also contains galactose (approx. 6.2%), uronic acid (approx. 22.4%) and sulfate (approx. 21.4%). A recent publication describes the properties in more detail:
Fitton H. J., Stringer D. N. and Karpiniec S. S., Therapies from Fucoidan: An Update, Marine Drugs, 13, 5920-5946 (2015)