Polyether marine toxins

Fig. 10.19. IDR-HSQC-TOCSY spectrum of the complex marine polyether toxin brevetoxin-2 (7). The data were recorded overnight using a 500 pg sample of the toxin (MW = 895) dissolved in 30 pi of d6-benzene. The data were recorded at 600 MHz using an instrument equipped with a Nalorac 1.7 mm SMIDG probe. Direct responses are inverted and identified by red contours relayed responses are plotted in black. The IDR-HSQC-TOCSY data shown allows large contiguous protonated segments of the brevetoxin-2 structure to be assembled, with ether linkages established from either long-range connectivities in the HMBC spectrum and/or a homonuclear ROESY spectrum.

The formation of the six-membered ether ring via epoxy ester-ortho ester cyclic ether rearrangement supports the hypothesis that epoxy ester-ortho ester cyclic ether rearrangement may be involved in the biosynthesis of ladder-type marine polyether toxins. This reaction represents a biomimetic preparation of medium ring cyclic ethers. 

Morohashi, A., Satake, M., Oshima, Y., and Yasumoto, T. 2000. Absolute configuration at C45 in 45-hydroxyyessotoxin, a marine polyether toxin isolated from shellfish. Biosc Biotech Biochem 64, 1761-1763. 

Satake, M., Biosynthesis of marine polyether toxin, yessotoxin, Tennen Yuki Kagobutsu Toronkai Koen Yoshishu, 42, 259, 2000. 

Dickey, R.W. et al.. Liquid chromatographic mass spectrometric methods for the determination of marine polyether toxins. Bull. Soc. Path. Ex., 85, 514—515, 1992. 

Lewis, R.J. et al., lonspray mass spectrometry of ciguatoxin-1, maitotoxin-2 and -3, and related marine polyether toxins, Nat. Toxins, 2, 56-63, 1994. 

A marine polyether toxin from the dinoflagellate Gam-bierdiscus toxicus, together with brevetoxins, cigua-... 

Okadaic acid (1), a marine polyether toxin, was first isolated as a potent antitumor agent from two sponges Halichondria okadai and H. melanodocia, and... 

Yessotoxin (YTX) 46, isolated from Patinopecten yessoensis, is a marine polyether toxin (Figure 7.15). The molecular structures of YTX (C55Hg202iS2Na2) consisting of 6/6/6/6/7/6/8/6/6/676 ether rings trans-fused, was determined by MS and NMR. 

B. Paz, A.H. Daranas, M. Norte, P. Robio, J.M. Franco and J.J. Fernandez, Yessotoxins, a Group of Marine Polyether Toxins An Overview , Mar. Drugs, [online computer file], 2008, 6, 73, Avail. URL http //www.mdpi.net/ marinedrugs/papers/md6020073.pdf... 

Liu, TZ. and Isobe, M. (2000) Synthesis of the H-I-J tricyclic fragment of ciguatoxin, a marine polyether toxin, Synlett, 266-268. 

Fuwa, H., Sasaki, M., and Tachibana, K. (2001) Synthetic studies on a marine polyether toxin, gambierol stereoselective synthesis of the EFGH ring system via B-alkyl Suzuki coupling. Tetrahedron, 57, 3019-3033. 

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