| Project/Area Number |
06044022
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| Research Category |
Grant-in-Aid for international Scientific Research
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| Allocation Type | Single-year Grants |
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| Section | Joint Research |
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| Research Institution | Faculty of Agriculture, Tohoku University |
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Principal Investigator |
YASUMOTO Takeshi Faculty of Agriculture, Tohoku University, 農学部, 教授 (20011885)
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| Co-Investigator(Kenkyū-buntansha) |
KASPAR Heirich f. Cawthron Institute, Nelson, New Zealand, 研究部長
SATAKE Masayuki Faculty of Agriculture, Tohoku University, 農学部, 助手 (90261495)
OSHIMA Yasukatsu Faculty of Agriculture, Tohoku University, 農学部, 助教授 (60111267)
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| Project Period (FY) |
1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1994: ¥2,100,000 (Direct Cost: ¥2,100,000)
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| Keywords | New Zealand / shellfish toxins / Neurotoxic shellfish toxins / Gymnodimine / Paralytic shellfish toxins / Gymnodinium cf.breve / Gymnodinium cf.mikimotoi / Alexandrium ostenferdii |
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| Research Abstract |
Chemical, toxicological, and etiological studies were conducted on the following three types of toxins found in shellfish and phytoplankton samples collected in New Zealand : neurotoxic shellfish toxins (NSP) in green mussels, a novel toxin found in oysters collected at Foveaux Strait, and paralytic shellfish toxins (PSP) in the dinoflagellates Alexandrium ostenferdii and A.minutum. Isolation of plankton and collection of toxci shellfish were undertaken by the researchers in the Cawhron Institute, Nelson, New Zealand. Structural studies of the toxins were conducted at Tohoku University.
NSP toxins in the mussels differed from any of the brevetoxins previously isolated from the Gymnodinium breve culture. The first toxin (TX1) presumably has a formula C53H79NO17S (Mw 1033), shares the same polycyclic ether skeleton with brevetoxin B (BTXB), but differs from BTXB in the side chain. The second toxin (TX2) was deduced to have a modified skeleton in which the ether bond of ring D of BTXB was cleaved, and the resulting -OH was esterified by a fatty acid (16 : 1 or 14 : 0). Presumably, 42-CHO in BTXB was oxidized to COOH in TX2. The structural determination of the third toxin (TX3) is underway. Both TX1 and TX3 activated Na channels, analogous with BTXB,but did not show any significant ichthyotoxicity.
From the Foveaux Strait oysters, a novel macrocarbocyclic imine named gymnodimine was isolated. The molecular formula C32H45NO4 (Mw 507) and the planar structure was established by spectroscopic analyzes. Presence of the toxin in the culture of G.cf.mikimotoi was confirmed by LC/MS analysis
PSP toxin profiles in four isolates of G.ostenferdii and one isolate of G.minutum were determined by HPLC analysis.
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