For the first time, an insect-plant system, Pieris brassicae fed with Brassica rapa var. rapa, was
tested for its biological capacity, namely, antioxidant (DPPH•, •NO, and O2
•- radicals) and antimicrobial
(bacteria and fungi) activities. Samples from the insect’s life cycle (larvae, excrements, exuviae, and
butterfly) were always found to be more efficient than the host plant. Also, P. brassicae materials, as
well as its host plant, were screened for phenolics and organic acids. The host plant revealed higher
amounts of both compounds. Two phenolic acids, ferulic and sinapic, as well as kaempferol 3-Osophoroside,
were common to insect (larvae and excrements) and plant materials, with excrements
being considerably richer. Detection of sulfated compounds in excrements, absent in host plant,
revealed that metabolic processes in this species involved sulfation. Additionally, deacylation and
deglycosilation were observed. All matrices presented the same organic acids qualitative profile, with
the exception of excrements.
