Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Chemical ecology of pyrrolizidine alkaloids.

Abstract

Specific features and functions of pyrrolizidine alkaloids (PAs) in plants are reviewed in the following sections: chemistry, distribution and biological activities; biosynthesis; translocation, allocation and storage; conversion of senecionine N-oxide into species specific alkaloid patterns, a system of high plasticity; acquisition and utilization of plant PAs by specialized herbivorous insects (including members of the Lepidoptera, Coleoptera, Orthoptera and Homoptera); chemical transformation of plant-acquired alkaloids in adapted insects (including Tyria jacobaeae feeding on Senecio jacobaea, Creatonotos transiens, Zonocerus variegatus and Oreina speciosissima); PAs are maintained as N-oxides in plants and sequestering insects; toxic free base versus nontoxic N-oxide, the success of PAs in adapted insects; and conclusions.