A Siphonotid Millipede (Rhinotus) as the Source of Spiropyrrolizidine Oximes of Dendrobatid Frogs

  title={A Siphonotid Millipede (Rhinotus) as the Source of Spiropyrrolizidine Oximes of Dendrobatid Frogs},
  author={Ralph A. Saporito and Maureen A. Donnelly and Richard L. Hoffman and H Martin Garraffo and John W. Daly},
  journal={Journal of Chemical Ecology},
Poison frogs of the neotropical family Dendrobatidae contain a wide variety of lipophilic alkaloids, which are accumulated from alkaloid-containing arthropods. A small millipede, Rhinotus purpureus (Siphonotidae), occurs microsympatrically with the dendrobatid frog Dendrobates pumilio on Isla Bastimentos, Bocas del Toro Province, Panamá. Methanol extracts of this millipede contain the spiropyrrolizidine O-methyloxime 236, an alkaloid previously known only from skin extracts of poison frogs… 

Formicine ants: An arthropod source for the pumiliotoxin alkaloids of dendrobatid poison frogs.

The presence of pumiliotoxins in formicine ants of the genera Brachymyrmex and Paratrechina, as well as the presence of these ants in the stomach contents of the microsympatric pumiliaotoxin-containing dendrobatid frog, Dendrobates pumilio, support the significance of ant-specialization and alkaloid sequestration in the evolution of bright warning coloration in poison frogs and toads.

Melyrid beetles (Choresine): a putative source for the batrachotoxin alkaloids found in poison-dart frogs and toxic passerine birds.

The presence of high levels of batrachotoxins in a little-studied group of beetles, genus Choresine (family Melyridae), and their high toxin concentrations suggest that they might provide a toxin source for the New Guinea birds.

Alkaloids in Bufonid Toads (Melanophryniscus): Temporal and Geographic Determinants for Two Argentinian Species

The alkaloid profile for Melanophryniscus stelzneri from a location in the province of Córdoba, Argentina, changed significantly over a 10-year period, probably indicating changes in availability of alkaloids from dietary arthropods, and that of M. rubriventris from four locations in the provinces of Salta and Jujuy, Argentina strongly differed.


A new, monophyletic taxonomy for dendrobatids is proposed, recognizing the inclusive clade as a superfamily (Dendrobatoidea) composed of two families (one of which is new), six subfamilies (three new), and 16 genera (four new).

Piperidine alkaloids from fire ants are not sequestered by the green and black poison frog (Dendrobates auratus)

It is possible that D. auratus are unable to sequester fire ant piperidines due to their long hydrocarbon side chains, a feature that makes them structurally different than most known alkaloids in poison frogs.

Individual and Geographic Variation of Skin Alkaloids in Three Species of Madagascan Poison Frogs (Mantella)

Alkaloid compositions in mantellid poison frogs are diverse and highly dependent on geographic location that appear to be largely determined by the nature and availability of alkaloid-containing prey items.

A Review of Chemical Defense in Poison Frogs (Dendrobatidae): Ecology, Pharmacokinetics, and Autoresistance

A summary of the ecological and evolutionary contexts underlying the origin and maintenance of chemical defenses across Dendrobatidae is presented and aspects of the pharmacokinetics of acquiring defensive substances in these amphibians are reviewed.


The most significant findings and studies that led to the proposal of the 'dietary hypothesis', which states that most of these alkaloids are sequestered unchanged from dietary arthropods, are reviewed.

First characterization of toxic alkaloids and volatile organic compounds (VOCs) in the cryptic dendrobatid Silverstoneia punctiventris

This study establishes HS-SPME/GC-MS as a new application for a simultaneous approach to amphibian alkaloids and VOCs in poison frogs while opens up new research questions to assess the co-occurrence of both type of compounds and to investigate the evolutionary significance of a defence gradient that includes olfactory avoidance, unpalatability, and toxicity in dendrobatids.

Sequestered Alkaloid Defenses in the Dendrobatid Poison Frog Oophaga pumilio Provide Variable Protection from Microbial Pathogens

The present study provides the first evidence that alkaloid variation in a dendrobatid poison frog is associated with differences in inhibition of anuran pathogens, and offers further support that alkAloid defenses in poison frogs confer protection against both pathogens and predators.



Dietary source for skin alkaloids of poison frogs (Dendrobatidae)?

The results indicate a dietary origin for at least some “dendrobatid alkaloids,” in particular the pyrrolizidine oximes, the tricyclic coccinellines, and perhaps the histrionicotoxins and gephyrotoxins.

Arthropod–Frog Connection: Decahydroquinoline and Pyrrolizidine Alkaloids Common to Microsympatric Myrmicine Ants and Dendrobatid Frogs

Panamanian poison frogs raised in a large, screened, outdoor cage and provided for six months with leaf-litter from the frog's natural habitat, accumulated a variety of alkaloids into the skin, including two isomers of the ant pyrrolizidine 251K and two isomer of the 3,5-disubstituted indolizidine 195B.

Alkaloids from bufonid toads (Melanophryniscus): decahydroquinolines, pumiliotoxins and homopumiliotoxins, indolizidines, pyrrolizidines, and quinolizidines.

Skins of bufonid toads of the genus Melanophryniscus contain several classes of alkaloids, including precoccinelline [193A] and alkaloid 236, an oxime methyl ether, which are present in one population of Melanophile toads stelzneri.

Alkaloids from Australian frogs (Myobatrachidae): pseudophrynamines and pumiliotoxins.

Australian frogs of the genus Pseudophryne contain two distinct classes of alkaloids: pseudophrynamines and pumiliotoxins, which were the predominant class in both species from Western Australia and all of the eastern species.

Bioactive alkaloids of frog skin: Combinatorial bioprospecting reveals that pumiliotoxins have an arthropod source

  • J. DalyT. Kaneko M. A. Donnelly
  • Biology, Environmental Science
    Proceedings of the National Academy of Sciences of the United States of America
  • 2002
“combinatorial bioprospecting” demonstrates that further collection and analysis of individual taxa of leaf-litter arthropods should reveal the taxa from which PTX, alloPTXs, and 5,8-disubstituted indolizidines are derived.

Buzonamine, a new alkaloid from the defensive secretion of the millipede, Buzonium crassipes.

Defensive Secretions of Millipeds

The millipeds, comprising the arthropodan class Diplopoda, are an ancient group dating back to Devonian times, and they have held their own to this day, despite the evolutionary diversification of those very animals, the vertebrates, insects, and arachnids, that have come to include the primary predacious enemies of milliped.

Spiropyrrolizidines: a new class of blockers of nicotinic receptors.