STRUCTURES AND CONFIGURATIONS OF CIGUATOXIN FROM THE MORAY EEL GYMNOTHORAX-JAVANICUS AND ITS LIKELY PRECURSOR FROM THE DINOFLAGELLATE GAMBIERDISCUS-TOXICUS
STRUCTURES AND CONFIGURATIONS OF CIGUATOXIN FROM THE MORAY EEL GYMNOTHORAX-JAVANICUS AND ITS LIKELY PRECURSOR FROM THE DINOFLAGELLATE GAMBIERDISCUS-TOXICUS
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DOI：
10.1021/ja00167a040
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发表时间：
1990-05-23
影响因子：
15
通讯作者：
YASUMOTO, T
中科院分区：
文献类型：
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作者：
MURATA, M;LEGRAND, AM;YASUMOTO, T
雪卡毒素（Ciguatoxin， CTX）是雪卡毒素的主要成分，是引起最广泛的非细菌性食物中毒的原因。该毒素分别来自于海鳗裸鼠（Gymnothorax javanicus）和其同系物冈比亚铁鱼（Gambierdiscus toxicus）。结合1H NMR二维相关和NOE实验进行结构解析，实验中CTX不超过0.35 mg，同系物不超过0.74 mg。在-20度的温度下，由于九元环周围的缓慢构象变化，1H NMR信号的展宽得到了加强，其中所有的3J质子连接和角质子周围的NOE都被清楚地显示出来。CTX的分子式为C60H86O19，其结构为由13个连续醚环（7/6/6/7/7/9/7/6/8/6/7/6-spiro-5）组成的短链毒素型聚醚。该同系物被证明是一种含氧较少的CTX类似物。通过1H NMR NOE实验、MM2能量计算和光谱模拟的详细分析，阐明了除CTX的C2外，它们的相对立体化学性质。
Ciguatoxin (CTX) is the topic principle of ciguatera, which is responsible for the most widespread food poisoning of nonbacterial origin. The toxin, isolated from the moray eel Gymnothorax javanicus, and its congener, from the causative dinoflagellate Gambierdiscus toxicus, were used for this study. The structure elucidation was carried out by combined use of 1H NMR 2D correlation and NOE experiments done with no more than 0.35 mg of CTX and 0.74 mg of the congener. Broadening of 1H NMR signals due to a slow conformational change around a nine-membered ring was sharpened by measurements at -20.degree.C, in which all 3J proton connectivities and NOE''s around angular protons were clearly indicated. The structure of CTX, which had a molecular formula of C60H86O19, was disclosed to be a brevetoxin-type polyether comprising 13 continuous ether rings (7/6/6/7/7/9/7/6/8/6/7/6-spiro-5). The congener was shown to be a less oxygenated analogue of CTX. Their relative stereochemistries, except for C2 of CTX, were clarified by detailed analyses of 1H NMR NOE experiments, MM2 energy calculations, and spectral simulations.