Distribution of uronic acid-containing polysaccharides in 5 species of shellfishes.

Mollusks are a rich source of uronic acid-containing polysaccharides (UACPs) possessing biological and pharmacological activities. In the present study, UACP compositions of different tissues from 5 species of edible shellfishes, namely Neverita didyma, Natica janthostomoides, Saxidomus purpurata, Cyclina sinensis, and Chlamys farreri were systemically analyzed. Totally 10 UACPs were observed, including chondroitin sulfate, heparin, an identified mannoglucuronan, 3 unknown glycosaminoglycans (GAGs, U1, U3 and U6) with hexuronic acid-hexosamine repeating units, and 4 unknown non-GAGs (U2, U4, U5 and U7) with hexuronic acid-hexose repeating units. U4-7 showed tissue- and species-specificity while the other UACPs prevalently existed in these shellfish tissues. UACP compositions in tissues from the same shellfish species were similar for S. purpurata and C. sinensis but different for C. farreri, N. didyma and N. janthostomoides. And this investigation also indicates that the similarity of UACPs composition between different shellfishes is related to the genetic relationship.