Elsevier

Carbohydrate Polymers

Volume 91, Issue 2, 16 January 2013, Pages 483-491
Carbohydrate Polymers

Selective sulfation of carrageenans and the influence of sulfate regiochemistry on anticoagulant properties

https://doi.org/10.1016/j.carbpol.2012.08.034Get rights and content
Under an Elsevier user license
open access

Abstract

Sulfated polysaccharides are recognized for their broad range of biological activities, including anticoagulant properties. The positions occupied by the sulfate groups are often related to the level of the inherent biological activity. Herein the naturally sulfated galactans, kappa-, iota- and theta-carrageenan, were additionally sulfated by regioselective means. The anticoagulant activity of the resulting samples was then studied using the aPTT in vitro assay. The influence of sulfate regiochemistry on the anticoagulant activity was evaluated. From kappa-carrageenan three rare polysaccharides were synthesized, one of them involved a synthetic route with an amphiphilic polysaccharide intermediate containing pivaloyl groups. Iota- and theta-carrageenan were utilized in a selective C6 sulfation at β-d-Galp units to produce different structures comprising trisulfated diads. All the samples were characterized by NMR (1D and 2D). The resulting aPPT measurements suggested that sulfation at C2 of 3,6-anhydro-α-d-Galp and C6 of β-d-Galp increased the anticoagulant activity.

Highlights

► Carrageenans were selectively sulfated to produce rare diads. ► The new diads synthesized were characterized by 1D and 2D NMR. ► Sulfated derivatives showed higher anticoagulant activities than native carrageenans. ► Sulfation at C2 of anhydro units and C6 of β-d-Galp improved anticoagulant activity.

Keywords

Sulfation
Carrageenans
Anticoagulant activity
Regiochemistry
Modified polysaccharides

Cited by (0)