• We have investigated isolation and structure determination of natural products and evaluated mode of their actions. We have especially focused on marine natural products causative for a food poisoning, diarrheic shellfish poisoning (DSP), which has spread worldwide and threatened regional fishery industry. Dinophysistoxin produced by the dinoflagellate Dinophysis spp. and okadaic acid, are thought to be responsible for DSP. Acute toxicity test using mice has been the primary method for detection of DSP in the fish market, though an alternative method to quantify DSP without sacrificing mice has been requested. We isolated OABP2, a novel okadaic acid binding protein, from the marine sponge Halichondria okadai and succeeded in expression of the recombinant OABP2 in E. coli, which eventually showed high affinity to the DSP toxins.

We are now working on visualization of OA by utilizing OABP2 in order to provide an easy and quick quantification method for DSP.

• Food Poisoning
• Diarrhetic Schell Fish Poisoning
• Dinophysistoxin
• Okadaic Acid
• Quantification Method