Structure and anticoagulant activity of a sulfated fucan from the sea cucumber Acaudina leucoprocta.

A sulfated fucan was extracted, purified, and characterized from Acaudina leucoprocta (a low value sea cucumber) to better understand and utilize this species. The structure of the sulfated fucan was elucidated using chemical and modern spectroscopic analyses including HPGPC, IR, AFM, GC-MS, and NMR, and its bioactivity was investigated. Our results showed that the sulfated fucan was mainly composed of → 3)-α-L-Fucp-(1→ linkage, and that the sulfate groups were substituted at the O-2 and/or O-4 positions of the fucose ring. In detail, the sulfated fucan consisted of Fuc0S (40%), Fuc2S4S (24%), Fuc2S (24%), and Fuc4S (12%). On average, there were seven sulfate groups on every eight fucose residues. Assay for anticoagulant activity indicated that the sulfated fucan displayed intrinsic anticoagulant activity and specific anti-thrombin activity through heparin cofactor II. Our results showed that this bioactive sulfated fucan could enable the high-value utilization of this low-value sea cucumber.