ALKALOIDS FROM DENDROBATID POISON FROGS - FURTHER PUMILIOTOXINS AND ALLOPUMILIOTOXINS AND A REASSIGNMENT OF THE KETO FUNCTION IN PUMILIOTOXIN-307F

Skin extracts from the Panamanian poison-frog Dendrobates pumilio have afforded further trace alkaloids of the pumiliotoxin-A class (6-alkylidene-8-hydroxy-8-methylindolizidines) and an allopumiliotoxin subclass (7-hydroxy-PTX-As). Structures for pumiliotoxins 209F and 225F and allopumiliotoxin 225E, all with four carbon 6-alkylidene side chains, for allopumiliotoxins 309D, 325A' and 325A'', all with ten carbon 6-alkylidene side chains, and a reassignment of the position of the keto function in the ten carbon 6-alkylidene side chain of pumiliotoxin 307F are presented. Carbon-13 magnetic resonance assignments for these and the 15-O-methyl ether artefacts of pumiliotoxin 307A and allopumiliotoxin 323B, are tabulated.