Enzymatic preparation and structural determination of oligosaccharides derived from sea cucumber (Acaudina molpadioides) fucoidan

► Sea cucumber fucoidan oligosaccharide was enzymatically prepared and analyzed. ► Oligosaccharide profile of enzymatic hydrolysate was determined by LC-MS. ► Four major oligosaccharides from trisaccharide to octasaccharide were purified. ► Delicate structures of the oligosaccharides were clarified by ESI-CID-MS/MS and NMR.