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

Autor(es)

Gonzalez, Mabel ^[1] ; Palacios-Rodriguez, Pablo ^[2] ; Hernandez-Restrepo, Jack ^[2] ; Gonzalez-Santoro, Marco ^[2] ; Amezquita, Adolfo ^[2] ; Brunetti, Andres E. ^{[3, 4]} ; Carazzone, Chiara ^[1]

Afiliação do(s) autor(es)

^[1] Univ Los Andes, Dept Chem, AA 4976, Bogota - Colombia

^[2] Univ Los Andes, Dept Biol Sci, AA 4976, Bogota - Colombia

^[3] Univ Sao Paulo, Fac Ciencias Farmaceut Ribeirao Preto, Dept Ciencias BioMol, BR-14040903 Ribeirao Preto, SP - Brazil

^[4] Univ Nacl Misiones, Fac Ciencias Exactas, Inst Biol Subtrop, Lab Genet Evolut, CONICET UNaM, N3300, Posadas - Argentina

• Tipo de documento: Artigo Científico
• Fonte: Frontiers in Zoology; v. 18, n. 1 AUG 26 2021.
• Citações Web of Science: 0

Resumo

Background Poison frogs are known for the outstanding diversity of alkaloid-based chemical defences with promising therapeutic applications. However, current knowledge about chemical defences in Dendrobatoidea superfamily has two sources of bias. First, cryptic, brown-colored species have been neglected in comparison to those conspicuously colored, and second, there has been little interest in characterizing metabolites other than alkaloids mediating defensive functions. In an effort to contribute to fill the gap of knowledge about cryptic species and broadening the spectrum of compounds analyzed we have applied head-space solid phase microextraction coupled to gas chromatography and mass spectrometry (HS-SPME/GC-MS) for extracting amphibian alkaloids and volatile organic compounds (VOCs) from Silverstoneia punctiventris. Results Using the skin from 8 specimens in 4 biological replicates we have found 33 different compounds. Twenty of them were classified as VOCs into 15 chemical classes including alkanes, alcohols, carbonyl compounds, methylpyridines, benzothiazoles, N-alkylpyrrolidines, pyrazines, and sesquiterpenoids, some of which were previously reported as repellents, defence compounds or defence pheromones in other organisms, and as sex pheromones in a treefrog. Interestingly, six of the remaining compounds were identified as alkaloids previously reported in other toxic/unpalatable dendrobatid frogs. Conclusions This is the first report of alkaloids and VOCs found in the Silverstoneia genus, which has been assumed for decades as non-chemically defended. 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. In addition, our results show that amphibian alkaloids could have a dual function (olfactory at distance, taste by contact) never explored before neither in Silverstonaeia nor in any other dendrobatid species. (AU)

• Processo FAPESP: 17/23725-1 - Análise genômico de bactérias simbióticas de pele em pererecas como fonte potencial de compostos voláteis
• Beneficiário: Andrés Eduardo Brunetti
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado
• Processo FAPESP: 14/20915-6 - Ecologia química em anuros: caracterização de compostos voláteis e feromônios peptídicos em secreções de peles de rãs
• Beneficiário: Andrés Eduardo Brunetti
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado