Grantee Research Project Results

Biotransformation of Toxic Pyrrolizidine Alkaloids From Prestonia portobellensis by Tithorea tarricina Caterpillars

EPA Grant Number: MA916359
Title: Biotransformation of Toxic Pyrrolizidine Alkaloids From Prestonia portobellensis by Tithorea tarricina Caterpillars
Investigators: Ochaney, Monica
Institution: Florida International University
EPA Project Officer: Hahn, Intaek
Project Period: January 1, 2004 through December 31, 2006
Project Amount: $60,215
RFA: GRO Fellowships for Graduate Environmental Study (2004) RFA Text | Recipients Lists
Research Category: Academic Fellowships , Fellowship - Natural and Life Sciences , Biology/Life Sciences

Objective:

Many plants employ toxic compounds to defend against predators and pathogens. Some arthropods, particularly butterflies and their larvae, have coevolved to use phytotoxins for defense against predation. Butterflies belonging to the subfamily Ithomiinae of the Nymphalidae sequester secondary metabolites from plants, including pyrrolizidine alkaloids (PAs). The objective of my research project is to determine the fate of these alkaloids. PAs may be used directly, detoxified, or employed by caterpillars to synthesize new compounds.

Approach:

Tithorea tarricina caterpillars obtain PAs from the host plant, Prestonia portobellensis (Apocynaceae). First, PAs in P. portobellensis plants will be compared with those found in T. tarricina caterpillars. This will be done to determine if T. tarricina larval PAs are the same as those found in P. portobellensis. Second, the qualitative and quantitative variation of PAs among larval stages in T. tarricina caterpillars will be assesed. To determine alkaloid profiles of T. tarricina caterpillars and P. portobellensis, collections will be made at Gamboa in the Republic of Panama. I will sample during both the rainy and dry season and for 1 month in each season. The research will determine intraspecific alkaloid variation in both P. portobellensis and T. tarricina and compare alkaloid profiles of these species. PA profiles will be analyzed using gas chromatography.

Supplemental Keywords:

fellowship, phytotoxins, pyrrolizidine alkaloids, defense mechanisms, biotransformation, predator defense, host plants, Tithorea tarricina , Prestonia portobellensis,, RFA, Scientific Discipline, Ecosystem Protection/Environmental Exposure & Risk, Ecosystem/Assessment/Indicators, exploratory research environmental biology, Biochemistry, Ecology and Ecosystems, Ecological Indicators, adaption mechanisms, biotransformation, arthopods, caterpillars, phytotoxins, pyrrolizidine alkaloids

Progress and Final Reports:

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.