Pumiliotoxin alkaloids biological activity

Pumiliotoxin B, biological activity, 221-223 Pyridine alkaloids, 255-257 epibatidine, 255-256 noranabasamine, 256-257... 

Nothing is known of the biological activity of 251F. The alkaloid fraction from Minyobates bombetes, containing 251F as a major alkaloid, caused severe locomotor difficulties, muscle spasms, and labored breathing, followed by minor convulsions, on injection into a mouse. However, these effects could be due to the pumiliotoxin B and congeners also present in this alkaloid fraction 151). 

Structure-activity correlations for pumiliotoxin-A class alkaloids have not been delineated because of the limited supplies available from nature. Pumiliotoxin B is more active in potentiating frog muscle contraction than is pumiliotoxin A, which in turn is much more active than pumiliotoxin 251D (cited in 24). Thus, hydroxyl groups in the side chain appear important to at least one biological activity of this class of alkaloids. 

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