Planta Med 2013; 79 - PO2
DOI: 10.1055/s-0033-1348782

Analysis of Individual Frog Skin Extracts from Dendrobates Auratus with Capillary NMR

RW Fitch 1, A Weng 2, RA Saporito 2
  • 1Department of Chemistry and Physics, Indiana State University, Terre Haute, IN 47809. Terre Haute South Vigo High School, Terre Haute, IN, 47802
  • 2Department of Biology, John Carroll University, University Heights, Ohio 44118

Dendrobatid frogs contain a variety of defensive alkaloids obtained from dietary arthropods, typically ants and mites. We recently examined a collection of Dendrobates auratus from Oahu Hawai'i which contain a variety of pumiliotoxins and decahydroquinoline dimers as major alkaloids along with a variety of minor and trace compounds. We report here our preliminary correlation of 1D and 2D NMR at 400 MHz using differential analysis techniques. Comparison with GC-MS data and authentic NMR spectra readily identified the major alkaloids (PTX251D/aPTX267A) and facilitated identification of minor alkaloids in the skins. Use of a capillary NMR probe (Protasis) confers substantial sensitivity improvements enabling analysis of extracts from individual specimens collected using transcutaneous amphibian stimulation (TAS) and whole skin extracts. Current work is focused on application of LC-NMR using UPLC columns for high-resolution analysis with time-slice and triggered stop-flow analysis. Our results to date will be presented.