Distribution analysis of polysaccharides comprised of uronic acid-hexose/hexosamine repeating units in various shellfish species.

Acidic polysaccharides are attractive functional ingredients in shellfish which are consumed as delicious and nutritious foods world widely. In the present study, acidic polysaccharides from 21 species of edible shellfish were characterized and quantified by analyzing their repeated disaccharides using the multiple reaction monitoring (MRM) mode of triple quadrupole mass spectrometer upon acid degradation and 1-phenyl-3-methyl-5-pyrazolone (PMP) derivatization. A total of 6 glycosaminoglycans (GAGs) and 8 non-GAGs with repeated disaccharide units of a hexuronic acid linked to a hexosamine or a hexose were detected. Among them, chondroitin sulfate, heparin, →4)-β-GlcA-(1 → 2)-α-Man-(1 → and →3)- β-GlcA-(1 → 3)-α-Gal-(1 → were identified unambiguously by comparing with the references. The quantification results revealed that the contents of these polysaccharide varied greatly among shellfish species with a maximum over 100 mg/100 g. Furthermore, the dendrogram of hierarchical clustering analysis indicated that the composition of acidic polysaccharides in some shellfish species was related with the genetic relationship. Thus, the present study provides a more comprehensive knowledge about the distribution of acidic polysaccharides in various shellfish species.