Levan-based Heparin-mimetic Polysaccharides

Ayca Akcay, Ebru Toksoy Oner

Industrial Biotechnology and Systems Biology (IBSB) Research Group, Department of

Bioengineering, Faculty of Engineering, Marmara University, Istanbul, Turkey

Exopolysaccharides (EPSs), which are secreted by microorganisms are natural, nontoxic,

biocompatible and biodegradable polysaccharides. Chemical modifications of

exopolysaccharides, such as phosphorylation, sulfation, oxidation, carboxylation, provide an

opportunity to increase their biological activities or their solubilities (Wu et al., 2007; Huang

et al., 2008; Mendes et al., 2009). Sulfated polysaccharides have important bioactivities

including antivirus, antioxidant, antitumor, and anticoagulant activities. (Mendes et al., 2009).

Levan is an EPS composed of fructose units joined by β-(2-6) linkages (Poli et al., 2009).

Considering the increasing interest in levan and its potential applications in medical industry,

the main aim of this study was to investigate the anticoagulant activity of this polysaccharide

and its sulfated derivatives with different sulfation degrees. The PT, APTT and TT assays

were performed for evaluating anticougulant activity. Results showed that the heparin-

mimetic activity increased with increasing degree of sulfation. On the other hand, natural or

aldehyde activated forms of levan showed no anticougulant activity. These results suggested

that sulfated levan derivatives could be explored as promising anticoagulant agents as

alternatives to heparin. These studies hold great importance for the medicinal applications of

levan and its chemical modifications. Financial support: TUBITAK, Project No. MAG-

111M232.

References

Huang et al., Carbohydrate Polymers, 303-308 (2008).

Mendes et al., International Journal of Biological Macromolecules, 305-309 (2009).

Poli et al., Carbohydrate Polymers, 651-657 (2009).

Wu et al., International Journal of Molecular Sciences, 670-679 (2007).