Elysia timida

When the sacoglossan Placobranchus ocellatus was immersed in seawater containing 14C sodium hydrogen carbonate, 14C label was incorporated into both 9,10-deoxytridachione (Structure 2.124) and the photorearrangement product photodeoxytridachione (Structure 2.125).242 In Elysia viridis, sodium [l-14C]propionate was incorporated into elysione (Structure 2.126), an ichthyotoxic metabolite found in the mollusc s mucus secretions.237 Attempts to repeat this propionate labeling experiment in Elysia timida and to test the putative role of acetate in the biosynthesis of 15-norphotodeoxytridachione (Structure 2.127) were unsuccessful.237 243 The metabolites shown in Structures 2.124, 2.125, 2.126, and 2.128, some of which were toxic, were present in the mucus secretion of Elysia timida, consistent with a defensive role.243 The hypothesis that these complex pyrones function as suncreens242 has been disputed.243... 

Isol. from the mollusc Elysia timida. [a] +26.5 (c, 0.5 in CHCI3). Similar to Crispatene, C-02004. 

Isol. from Elysia timida and Placobranchus ocellatus. [aj ... 

Gavagnin, M., Spinella, A., Castellucio, E., Cimino, G., and Marin, A. (1994c) Polypropionates from the Mediterranean mollusk Elysia timida.J. Nat. Prod., 57, 298-304. 

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