Structure and Activities of Natural Complex Polysaccharides

Glycosaminoglycans (GAGs), hyaluronic acid or hyaluronan (HA), keratan sulfate (KS), chondroitin sulfates (CSs) and heparin (Hep)/heparan sulfate (HS), are complex ubiquitous natural polysaccharides that exhibit a wide range of biological functions by participating and regulating multiple cellular events and (patho)physiological processes. They are generally present either as free chains (HA) or as side chains of proteoglycans (PGs) (CS/dermatan sulfate (DS), Hep/HS and KS) and are most often found in cell membranes and in the extracellular matrix. The recent emergence of improved analytical tools for the study of these complex sugars has produced a virtual explosion in the field of glycomics. In particular, the well-known therapeutic applications of some of these macromolecules, in particular Hep as an anticoagulant and antithrombotic (macro)molecule and CS in the treatment of osteoarthritis (OA), and the increased understanding of GAG structure-function relationship has led to the discovery of novel drugs for the possible treat¬ment of some serious diseases.