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|Section2= |Section3= |Section4= |Section5= |Section6= |Section7= |Section8= }} Okadaic acid, C44H68O13, is a toxin produced by several species of dinoflagellates, and is known to accumulate in both marine sponges and shellfish. One of the primary causes of diarrhetic shellfish poisoning, okadaic acid is a potent inhibitor of specific protein phosphatases and is known to have a variety of negative effects on cells. A polyketide, polyether derivative of a C38 fatty acid, okadaic acid and other members of its family have shined light upon many biological processes both with respect to dinoflagellete polyketide synthesis as well as the role of protein phosphatases in cell growth. == History == As early as 1961, reports of gastrointestinal disorders following the consumption of cooked mussels appeared in both the Netherlands and Los Lagos. Attempts were made to determine the source of the symptoms, however they failed to elucidate the true culprit, instead implicating a species of microplanctonic dinoflagellates.〔 In the summers of the late 1970s, a series of food poisoning outbreaks in Japan lead to the discovery of a new type of shellfish poisoning. Named for the most prominent symptoms, the new Diarrhetic Shellfish Poisoning (DSP) only affected the northern portion of Honshu during 1976, however by 1977 large cities such as Tokyo and Yokohama were affected. Research into the shellfish consumed in the affected regions showed that a fat soluble toxin was responsible for the 164 documented cases, and this toxin was traced to mussels and scallops harvested in the Miyagi prefecture. In northeastern Japan, a legend had existed that during the season of paulownia flowers, shellfish can be poisonous. Studies following this outbreak showed that toxicity of these mussels and scallops appeared and increased during the months of June and July, and all but disappeared between August and October.〔 Elsewhere in Japan, in 1975 Fujisawa pharmaceutical company observed that the extract of a black sponge, ''Halichondria okadai'', was a potent cytotoxin, and was dubbed Halichondrine-A. In 1981, the structure of one such toxin, okadaic acid, was determined after it was extracted from both the black sponge in Japan, ''Halichondria okadai'', for which it was named, and a sponge in the Florida Keys, ''Halichondria Melanodocia''. Okadaic acid sparked research both for its cytotoxic feature and for being the first reported marine ionophore. One of the toxic culprits of DSP, dinophysistoxin-1 (DTX-1), named for one of the organisms implicated in its production, ''Dinophysis fortii'', was compared to and shown to be very chemically similar to okadaic acid several years later, and okadaic acid itself was implicated in DSP around the same time.〔 Since its initial discovery, reports of DSP have spread throughout the world, and are especially concentrated in Japan, South America and Europe.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「okadaic acid」の詳細全文を読む スポンサード リンク
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