Umbraculum mediterraneum

The ichthyotoxic diacylglycerol umbraculumin C (203) was isolated from the Mediterranean ophistobranch Umbraculum mediterraneum [206], The stereochemistry of compound 203 was determined by chemical interconversion and total synthesis [207]. 

Umbraculumin C (90), characterized by the presence of a trans-3-(methylthio)-acrylic acyl residue, is a diacylglycerol obtained from the skin of the opisthobranch mollusc Umbraculum mediterraneum [96]. Taylor and co-workers determined the absolute configuration of 90 by total synthesis [97] while Sodano et al. reached the same conclusion by derivatisation of the natural compound [98]. Compound 90 displayed ichthyotoxic activity against the mosquito fish at 0.1 pg/ml and should represent the deterrent of this organism against predators [96]. 

Cimino, G., Crispino, A., Spinella, A., and Sodano, G. (1988a) Two ichthyotoxic diacylglycerols from the opisthobranch mollusc Umbraculum mediterraneum. Tetrahedron Lett., 29, 3613-3616. 

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