Polyether sponge

Tachibana, K., et al., Okadaic acid, a cytotoxic polyether from two marine sponges of the genus Halichondria, JACS, 103, 2469, 1981. 

Hirata Y, Uemura D. (1986) Halichondrins — antitumor polyether macrolides from a marine sponge. Pure Appl Chem 58 701-710. 

Some 1,2-dioxanes and 1,2-dioxolanes derivatives such as the two diastereomers of methyl esters of peroxyplakoric acid (A3 and B3) (85) isolated from marine sponges Plakortis sp., have proven to possess good antimalarial activity, with IC50 values of about 50 ng/mL for both compounds. Furthermore, a polyether (86) recently isolated from marine Streptomyces sp. H668 also displayed a useable antimalarial activity, with an IC50 value of about 150 ng/mL. ... 

This paper describes a method for improving hydrophilicity by using radiation-induced grafting of flexible polyurethane (polyether) foam with polar vinyl monomers. By this procedure, the normally hydrophobic material can be converted into a remarkably water-wettable sponge. 

Litaudon, M., Hickford, S. J. H., and Lill, R. E., Antitumor polyether macrolides new and hemisyn-thetic halichondrins from the New Zealand deep-water sponge Lissodendoryx sp., J. Org. Chem., 62, 1868, 1997. 

During a synthesis of the polyether antibiotic X-206. Evans and co-workers503 accomplished the protection of a hindered secondary alcohol with benzyl bro momethyl ether (BOMBr) in the presence of proton sponge [l,8-bis(dimethyl-amino )naphthalene], without racemising the two stereogenic centres adjacent to the ketone function [Scheme 4.281],... 

Sakai, R., and Rinehart, K.L. 1995. A new polyether acid from a cold water marine sponge, a. Phakellia species. J Nat Prod 58, 773-777. 

Schmitz, F.I, Prasad, R.S., Gopichand, Y, Hossain, M.B., van der Helm, D., and Schmidt, P. 1981. Acanthifolicin, a new episulfide-containing polyether carboxylic acid from extracts of the marine sponge Pandaros acanthifolium. J Am Chem Soc 103, 2467-2469. 

Tachibana, K., Scheuer, P.J., Tsukitani, Y, Kikuchi, H., Van Engen, D, Clardy, I, Gopichand, Y, and Schmitz, EJ. 1981. Okadaic acid, a cytotoxic polyether from two marine sponges of the genus Halichondria. J Am Chem Soc 103, 2469-2471. 

A diverse array of polyketide metabolites are found in marine organisms, which range from simple oxylipins to highly complex polyethers and macrolides. Particularly intriguing are ladder-shaped polyethers of dinofragellate origin and sponge macrolides. 

The sponge Halichondria okadai contains a polyether metabohte named okadaic acid (16) that was also isolated as a causative agent of diarrhetic shellfish poisoning (DSP) from mussels and other bivalves (14). However, the real producers are dinoflagellates of the genus Dinophysis. It is a potent cancer promoter that was found to be caused by inhibition of protein phosphatases 1 and 2A at nanomolar levels. Pectenotoxins are also involved in DSP and are produced by Dinophysis spp. pectenotoxin 2 (17) inhibits actin polymerization (14). 

Halichondrin B (28), which is a polyether macrolide isolated from H. okadai, shows promising antitumor activity and has entered phase 1 clinical trials (2, 15). It inhibits polymerization of tubulin by binding to the colchicine domain. The macrocyclic portion seems to be essential for the activity (2). Halichondrins have been found in several species of sponges, which indicates their microbial origin (6). 

Okadaic acid is a polyether derivative of a 38-carbon fatty acid elaborated by marine dinoflagellates and accumulated in sponges and in mussels Halichondria okadal). It acts as a selective inhibitor of protein phosphatase-1 and -2A, and is used as a pharmacological and biochemical tool. 

Protein phosphatases inhibitors. Okadaic acid from marine dinoflagellates that accumulates in a black sponge (Halichondria okadal) and mussels, is a polyether fatty acid derivative. It causes a contracture of smooth and cardiac muscle, is a tumour promoter and selectively inhibits protein phosphatase-1 and phosphatase-2A. It is a causative agent in diarrhoretic shellfish poisoning. 

The complex marine polyether halichondrin B (Eigure 8.15) was first isolated from a Japanese sponge by Uemura et and was subsequently reisolated by Pettit from... 

Diverse polyketides ranging from simple oxylipins to highly complex polyethers and macrolides have been reported from marine sponges. 

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