Indolizidine from Dendrobates auratus

The alkaloid 249H, Fig. (11), was isolated from the skin extracts of the poisonous frog Dendrobates auratus of the Isla Taboga of the Pacific coast of Panama [26]. A sample containing only traces of impurities was obtained by successive column chromatography of the methanolic skin extract. H and C NMR spectroscopy and correlation spectra were only consistent with a branched substituent, the first to be reported for simple indolizidines isolated from frog skin, and an unusual cw-fused trisubstituted indolizidine nucleus. 

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