• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.7
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• pp.926-931
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• 2007

Diarrhetic shellfish poisons (DSP) such as okadaic acid (OA), dinophysistoxin-1 (DTX1), pectenotoxin-1(PTX1), PTX2, PTX6 and yessotoxin (YTX) were determined simultaneously by LC-MS/MS and mouse bioassay in the shellfishes (oyster, mussel, Washington purple clam, ark shell, scallop and short necked clam) collected at Tongyeong, from March to September, 2006. Oyster and mussel were found to contain DSP (0.05${\sim}$0.1 MU/g) in March by mouse bioassay; however, no DSP components were detected on the LC-MS/MS. Also, a small amount of DTX1 (0.05 ${\mu}g/g$) in mussel (June) and OA (0.01${\sim}$0.02 ${\mu}g/g$) in 5 species of shellfishes(August) were determined by LC-MS/MS.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.3
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• pp.193-202
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• 1991

Antimicrobial substances were screened by paper disk plate method in marine sponges, Halichondria okadai, Halichendria sp., H iaponica and Haliclona Pemollis, collected from the south coast of Korea. Antibacterial components were detected in two species, H okadai and Halichondria sp.. Three components such as benzoic acid, okadaic acid(OA) and dinophysistoxin-1(DTX1) were identified from these sponges as the antimicrobial compounds by MS and NMR spectral data. OA$(550{\~}600{\mu}g/kg)$ and $(400{\~}490{\mu}g/kg)$ were determined from the wet H okadai and Halichondria sp., respectively, by using fluorometric HPLC analysis with 9-anthryldiazomethane(ADAM) as fluorescent labelling reagent.

• Korean Journal of Food Science and Technology
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• v.44 no.4
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• pp.390-392
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• 2012

Diarrhetic shellfish poisoning toxins were investigated by liquid chromatography-electrospray ionization mass spectrometry (LC-MS/MS). Okadaic acid (OA), Dinophysistoxin-1 (DTX1), Pectonotoxin2, (PTX2) and Yessotoxin (YTX) in bivalves were quantified. OA were found in four samples; mussel Mytilus edulis (0.001 ${\mu}g/g$), Oyster Crassostrea gigas (0.004 and 0.001 ${\mu}g/g$) and manila clam Ruditapes philippinarum (0.001 ${\mu}g/g$). DTX1, PTX2, and YTX were not detected from all of the samples examined.

• Korean Journal of Food Science and Technology
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• v.41 no.4
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• pp.458-463
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• 2009

To establish and validate a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the rapid and accurate quantitation of diarrhetic shellfish poisoning (DSP) toxins, we compared the results from different mobile phases and columns used for their analysis and collision energies for MS/MS experiments. Clear peaks of okadaic acid (OA) and dinophysistoxin-1 (DTX1) were obtained by using a mobile phase comprising aqueous acetonitrile containing 2 mM ammonium formate and 50 mM formic acid. The collision energies were optimized to facilitate the most sensitive detection for each toxin, namely, OA, DTX1, pectenotoxin-2 (PTX2), or yessotoxin (YTX). Further, the maximum ion response was obtained at a collision energy of 48 V for OA and DTX1. We compared the analytical performance of $C_8$ and $C_{18}$ columns. A wide range of toxins namely, OA, DTX1, PTX2, and YTX, except DTX3, were detected by both the columns. Although DTX3 was only detected by the $C_8$ column, we found that the $C_{18}$ column was also suitable for the quantitation of OA and DTX1 the toxins responsible for inducing diarrhea. The limit of detection of OA and DTX1 by the established LC-MS/MS conditions was 1 ng/g, and the limit of quantitation of the toxins under the same conditions was 3 ng/g. The process efficiencies were 91-118% for oysters (Crassostrea gigas) and 96-117% for mussels (Mytilus galloprovincialis) further, we observed no significant effect of matrix during the ionization process in LC-MS/MS. The comparison between mouse bioassay (MBA) and LC-MS/MS yielded varying results because low concentrations of OA and DTX1 were detected by LC-MS/MS in some shellfish samples, which provided positive results on MBA for DSP. The analysis time required by MBA for DSP analysis can be reduced by LC-MS/MS.

• Journal of Food Hygiene and Safety
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• v.37 no.3
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• pp.159-165
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• 2022

In this study, heavy metals (lead, cadmium, and mercury) and shellfish poisoning toxins (diarrhetic shellfish poisoning toxins, amnesic shellfish poisoning toxins) were investigated in a total of 104 shellfishes. According to the analysis of heavy metals, lead (Pb) was detected in the range of 0.0177-0.5709 mg/kg, cadmium (Cd) was detected in the range of 0.0226-1.4602 mg/kg, and mercury (Hg) was detected in the range of 0.0015-0.0327 mg/kg. Levels of Pb, Cd, and Hg were acceptable by Korean standards. Okadaic acid (OA) and dinophysistoxin-1 (DTX-1) were investigated for monitoring of diarrhetic shellfish poisoning toxins and OA and DTX-1 were not detected. As a result of monitoring of amnesic shellfish poisoning toxins, domoic acid was detected in 5 of 104 samples and detection ratio was 4.8%. The detection period was found as follows; 1 case in January, 1 case in February, 1 case in May, 2 cases in September. These showed that continuous monitoring for the management of shellfish poisoning toxins and heavy metals is required. In addition, this study can be used as reference data to strengthen managing heavy metals in fishery products.

• Journal of Food Hygiene and Safety
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• v.38 no.6
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• pp.409-419
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• 2023

Okadaic acid (OA) group toxins, including OA and its analogs, such as dinophysis toxins (DTXs), have been reported to cause diarrheal shellfish poisoning (DSP). These toxins are primarily produced by dinoflagellates and are accumulated in bivalves. Recently, the presence of Dinophysis sp., a causative alga of DSP, has been reported along the coasts of Korea, posing a potential risk of contamination to domestic seafood and exerting an impact on both the production and consumption of marine products. Accordingly, the European Food Safety Authority (EFSA) and the World Health Organization (WHO) have established standards for the permissible levels of OA group toxins in marine products for safety management. Additionally, in line with international initiatives, the domestic inclusion and regulation of DTX2 among the substances falling under the purview of management outlined by the 2022 diarrheal shellfish toxin standard have been implemented. In this study, we reviewed the physicochemical properties of OA group toxins, their various exposure routes (such as acute toxicity, genotoxicity, reproductive and developmental toxicity), and the relative toxicity factors associated with these toxins. We also performed a comparative assessment of the methods employed for toxin analysis across different countries. Furthermore, we aimed to conduct a broad review of human exposure cases and assess the international guideline for risk management of OA group toxins.