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

Sea cucumber fucoidan is a major bioactive component of sea cucumber. Sea cucumber is widely consumed in East Asian countries as healthy food. Employing the degrading enzyme from the marine bacterium strain Flavobacteriaceae CZ1127, sea cucumber (Acaudina molpadioides) fucoidan oligosaccharides were prepared by enzymatic hydrolysis. The oligosaccharide profile of the hydrolysate was determined by liquid chromatography coupled with mass spectrometry (LC-MS). With the assistance of LC-MS, four major oligosaccharides in the hydrolysate were purified. By using tandem mass spectrometry and nuclear magnetic resonance, delicate structures of the oligosaccharides were verified as α-l-Fucp-1 → 3-α-l-Fucp(2,4OSO32-)-1 → 3-α-l-Fucp, α-l-Fucp-1 → 3-α-l-Fucp(2,4OSO32-)-1 → 3-α-l-Fucp-1 → 3-α-l-Fucp, α-l-Fucp-1 → 3-α-l-Fucp(2,4OSO32-)-1 → 3-α-l-Fucp-1 → 3-α-l-Fucp-1 → 3-α-l-Fucp-1 → 3-α-l-Fucp(2,4OSO32-)-1 → 3-α-l-Fucp and α-l-Fucp-1 → 3-α-l-Fucp(2,4OSO32-)-1 → 3-α-l-Fucp-1 → 3-α-l-Fucp-1 → 3-α-l-Fucp-1 → 3-α-l-Fucp(2,4OSO32-)- 1 → 3-α-l-Fucp-1 → 3-α-l-Fucp.