• Journal of Food Hygiene and Safety
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• v.10 no.2
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• pp.73-79
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• 1995

Incidents of seafood and massive fish kills have been rapidly increasing in both frequency and geographical distribution and the socioeconomic impacts brought by those incidents. However, the biological origins of those marine toxins have not been well clarified. Most of the marine organisms investigated are filter-feeder, which accumulate toxins from their food and/or their symbiotic microalgae. We have examined the action on rabbit platelets of marine toxins isolated from cultured dinoflagellates and sponge collected at Okinawa. Maitotoxin (MTX) is a water-soluble toxin isolated from the cultured dinoflagellate Gambierdiscus toxicus which causes a seafood poisoning in tropical regions. Zooxanthellatoxin A (ZT-A) was isolated from exteracts of cultured symbiotic dinoflagellate Symbiodinium sp. (socalled zooxanthella) from flatworms of the genus Amphiscolops collected at Okinawan marine sponge Theonella sp. MTX caused a disaggregation and a dissolution of large aggregates. ZT-A caused a dissolution of small aggregates followed by a increment of light tranmission. TZ-A caused an initial and transient shape change followed by a sustained aggregation and a increment of large aggregates. In conclusion, marine toxins exert unique patterns on the light trasmission and the size of aggregates in rabbit platelets by their concentrations and kinds

• 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.

• Journal of the Korean Magnetic Resonance Society
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• v.28 no.3
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• pp.25-31
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• 2024

Toxins produced by marine toxigenic algae have garnered growing attention due to their detrimental impacts on marine ecosystem, aquaculture, and human health. Among these, diarrhetic shellfish poisoning (DSP) toxins, such as okadaic acid (OA), are of particular concern. In this study, we report the successful isolation and structural elucidation of three new derivatives of OA from the marine dinoflagellate Prorocentrum lima. These newly identified compounds, OA-2Me-C7, OA-2-Me-C8, and OA-1-Me-C8, were characterized through a comprehensive series of NMR experiments, combined with structural comparisons to the well-known OA. The identification of these derivatives contributes to the expanding knowledge of DSP toxin diversity and provides new insights into the structural variations of these harmful algal toxins.

• Korean Journal of Environmental Biology
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• v.17 no.3
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• pp.217-232
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• 1999

The author made a special review on/red-tides from the following points: definition, terms, yearly progress of researches, causative organisms, searching the causes, toxins, a loss of lives, damages of aquatic products, reducing aquacultural damages and removal efficiency. Red-tides in Korea were caused by diatoms in the early 1960’s, in the end of 1970’s it was caused by non-toxic dinoflagellates when marine pollutions were growing more and more serious. In the end of 1980’s, red-tides were caused by toxic dinoflagellates. Red-tide was only found in selected areas at first, but recently large-scaled red-tides are frequently found in the southern coastal waters of Korea, causing huge losses of marine life. A plan is greatly needed to reduce the damaging red-tides, and removal systems need to be developed.

• Journal of Food Hygiene and Safety
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• v.35 no.4
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• pp.291-303
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• 2020

Marine organism-derived toxins have negative effects not only on human health but also in aquaculture, fisheries, and marine ecosystems. However, traditional analytical methods are insufficient in preventing this threat. In this paper, we reviewed new rapid methods of toxin detection, which have been improved by adopting diverse types of nanomaterials and technologies. Moreover, we herein describe the main strategies for toxin detection and their related sensing performance. Notably, to popularize and commercialize these newly developed technologies, simplifying the process of pre-treating real samples real samples is very important. As part of these efforts, numerous studies have reported pretreatment methods based on the antibody-immobilized magnetic nanoparticles, and some cases have applied nanoparticles to enhance the sensing performance by utilizing the intrinsic catalytic activity. Furthermore, some reports have introduced fluorescent nanoparticles, such as quantum dots, to represent the lower detection limits of conventional enzyme-based colorimetric methods and lateral flow assays. Some studies using electrochemical measurements based on aptamer-nanoparticle complexes have also been announced. In addition, as the response to new toxins generated by changes in the marine environment is still lacking, further research on diagnostic and detection is also greatly needed for these kinds of marine toxins and their derivatives.

• Toxicological Research
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• v.17
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• pp.105-108
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• 2001

Several marine toxins with macrolide structure have been found to act on actin. One of these toxins is mycalolide B isolated from the genus Mycale. This compound belongs to macrolide antibiotics and consists of tris-oxazole with strong cytotoxic activity ($IC_{50}$: 10-50 nM for growth of L1210 murine leukemia cells). This compound was found to be an actin-depolymerizing agent with the mode of action distinct from that of the known actin inhibitor, cytochalasin D. Tolytoxin, a macrolide isolated from cyano-bacteria with similar chemical structure to mycalolide B, seems to have similar effect. Another macrolide compound, aplyronine A, showed the effects similar to those of mycalolide B. Although bistheonellide A, a dimeric macrolide, did not show a severing effect, it de polymerized F-actin and sequestered G-actin by forming 1 : 2 complex with G-actins. Swinholide A has a structure and effects similar to those of bistheonel-lide A. In conclusion, mycalolide B, tolytoxin, aplyronine A, bistheonellide A and swinholide A are the members of "actin de polymerizing macrolide" the mechanism of which is different from that of cytochalasin D.halasin D.

• Toxicological Research
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• v.32 no.3
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• pp.215-223
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• 2016

This study is to investigate the biological, biochemical and cytotoxic effects of puffer fish (Arothron stellatus) toxin extracts under in-vitro condition. Extracted toxins from various organs of puffer fish were purified by using active charcoal column, and Bio-gel-P2 column chromatography. The lethality of toxin was tested in crabs, which consists of neurotoxic compounds. The degree of the brine shrimp lethality assay was found directly proportional to the concentration of the toxin extracts, which was well supported by hemolytic assay. The experimental results suggested that the gonad was found higher toxins than the liver and muscles. The mortality rate of brine shrimp nauplii was increased with the raise of concentrations of toxin level. Among the different doses and time dependent cytotoxic effect of human cervical carcinoma (HeLa) cells were showed $4.0{\mu}g/mL$ of toxin, which was effectively inhibited cancer cell proliferation. HPLC and TLC analysis was revealed that the A. stellatus toxin contains tetrodotoxin (TTX), related compounds 4-epi TTX and anhydro-TTX. The present results suggested that the A. stellatus contain TTX as a major and anh-TTX as a minor toxin. It could be the potential candidate in the field of anticancer drug discovery against human cervical cancer cells. The present data is confirming that the puffer fish toxin as an interesting source of novel bioactive natural compounds with potent applications in pharmacology.

• Fisheries and Aquatic Sciences
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• v.12 no.3
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• pp.227-235
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• 2009

The marine toxic dinoflagellate Alexandrium catenella has been implicated in numerous paralytic shellfish poisoning (PSP) events in many countries. Due to difficulties in rapidly identifying A. catenella, field-based study of this species has been problematic. The present study developed a TaqMan format A. catenella-specific probe for real-time PCR assay (specific to Korean genotype) based on LSU rDNA sequence information for studying geographic and temporal distribution of the species in surface sediments and water columns of Jinhae Bay, Korea. The field survey from 2007 to 2008 revealed that A. catenella occurred in most seasons at low densities, mostly below 1 cell $mL^{-1}$, and was more abundant in spring (maximum cell density of 2 cells $mL^{-1}$) when shellfish exceed the quarantine toxin level for PSP toxins in Jinhae Bay.

• Journal of Environmental Science International
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• v.18 no.12
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• pp.1331-1338
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• 2009

Marine dinoflagellate Alexandrium minutum producing paralytic shellfish toxins is responsible for paralytic shellfish poisoning (PSP). To investigate its temporal distributions in Chinhae Bay where PSP occurs annually, SYBR Green I based A. minutum-specific real-time PCR probe was developed on the LSU rDNA region. Assay specificity and sensitivity were tested against related species, and its specificity was further confirmed by sequencing of field-derived samples. Ten months field survey in 2008 (a total 100 surface water samples) by using the real-time PCR probe showed that A. minutum was detected at very low densities of 1-4 cells $L^{-1}$ in May and June being spring in Chinhae Bay, Korea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.6
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• pp.669-674
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• 2017

Paralytic shellfish toxins (PSTs) are produced by marine dinoflagellate phytoplankton Alexandrium spp. and Gymnodinium spp. These toxins accumulate in filter feeding organisms such as bivalves and the ingestion of contaminated shellfish can cause illness in humans. The mouse bioassay (MBA) has been the preferred PST testing method worldwide for more than 50 years. However, this assay has several disadvantages, such as detection limits, non-toxic-profiles, and the ethical issues of using animals. The aim of this study was to establish an alternative to the MBA method for testing for PSTs. We optimized the analysis conditions of a post-column oxidation-high performance liquid chromatography (PCOX-HPLC) method and the Scotia Rapid Test Kit, and then compared the accuracy of these methods to the MBA method. The results demonstrated a strong correlation between the PCOX-HPLC method and the MBA, although the PCOX-HPLC method required expensive equipment and standard material, and was time consuming. The Scotia Rapid Test Kit promises to be a useful tool, as it provided rapid and qualitative results, although the method sometimes gave a false positive result that could not be explained by toxin profiles.