Oversulfated dermatan sulfate and heparinoid in the starfish Lysastrosoma anthosticta: structures and anticoagulant activity

Abstract Crude anionic polysaccharides extracted from the Pacific starfish Lysastrosoma anthosticta were separated by anion-exchange chromatography into fractions LA-F1 and LA-F2. The main fraction LA-F1 was solvolytically desulfated giving rise to preparation LA-F1-DS with a structure of dermatan core [→3)-β- d -GalNAc-(1→4)-α- l -IdoA-(1→]n. Reduction of LA-F1 afforded preparation LA-F1-RED composed mainly of the repeating disaccharide units →3)-β- d -GalNAc4R-(1→4)-α- l -Ido2S3S-(1→, where R was SO3– or H. Analysis of the NMR spectra of the parent fraction LA-F1 led to determine the main component as the oversulfated dermatan sulfate LA-Derm bearing sulfate groups at O-2 and O-3 of α- l -iduronic acid, as well as at O-4 of some N-acetyl- d -galactosamine residues. The minor fraction LA-F2 contained a mixture of LA-Derm and heparinoid LA-Hep, the latter being composed of the fragments →4)-α- d -GlcNS3S6S-(1→4)-α- l -IdoA2S3S-(1→ and →4)-α- d -GlcNS3S-(1→4)-α- l -IdoA2S3S-(1→. The presence of 2,3-di-O-sulfated iduronic acid residues is very unusual both for natural dermatan sulfate and heparinoid. Preparations LA-F1, LA-F2 and LA-F1-RED demonstrated significant anticoagulant effect in vitro.