Indolizidine 239Q and quinolizidine 275I. Major alkaloids in two Argentinian bufonid toads (Melanophryniscus).
Alkaloid profiles in skin of poison frogs/toads (Dendrobatidae, Mantellidae, Bufonidae, and Myobatrachidae) are highly dependent on diet and hence on the nature of habitat. Extracts of the two species of toads (Melanophryniscus klappenbachi and Melanophryniscus cupreuscapularis) from similar habitats in the Corrientes/Chaco Provinces of Argentina have similar profiles of alkaloids, which differ considerably in profiles from other Melanophryniscus species from Brazil, Uruguay and Argentina. Structures of two major alkaloids 239Q (1) and 275I (2) were determined by mass, FTIR, and NMR spectral analysis as 5Z,9Z-3-(1-hydroxybutyl)-5-propylindolizidine and 6Z,10E-4,6-di(pent-4-enyl) quinolizidine, respectively. A third alkaloid, 249F (3), is postulated to be a homopumiliotoxin with an unprecedented conjugated exocyclic diene moiety.
Laboratory of Bioorganic Chemistry, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, DHHS, Bethesda, MD 20892, USA.
John W
JW
Daly
H Martin
HM
Garraffo
Thomas F
TF
Spande
Herman J C
HJ
Yeh
Paola M
PM
Peltzer
Pedro M
PM
Cacivio
J Diego
JD
Baldo
Julián
J
Faivovich
D000470:Alkaloids / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D000818:Animals; D001118:Argentina; D002025:Bufonidae / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D005766:Gastrointestinal Contents / Q000737:chemistry; D054836:Indolizidines / Q000032:analysis / Q000737:chemistry* / Q000302:isolation & purification; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D054837:Quinolizidines / Q000032:analysis / Q000737:chemistry* / Q000302:isolation & purification; D012867:Skin / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
D000470:Alkaloids; D054836:Indolizidines; D054837:Quinolizidines