ABSTRACT A validation study of a reverse-phase high-performance liquid chromatographic assay for the quantification of two furanocoumarins (psoralen and bergapten) in soft extract obtained from Brosimum gaudichaudii Trécul, Moraceae, roots was conducted. The developed method was sensitive, rapid, reproducible, easy and precise, and showed linearity (r > 0.99) in the range of 10–64 µg/ml for psoralen, and 9–56 µg/ml for bergapten. It also showed a good efficiency for the photodegradation analysis of psoralen and bergapten in the soft extract. The photostability results showed that the Higuchi model presented the best fitting to the obtained data. Both chemical markers showed stability over 2.6 days, suggesting potential applications of the extract in obtaining intermediate products from this plant material. Furanocoumarins take around 30 min to be activated by UV light, reaching the maximum biological potential. Thus, the results obtained to the Higuchi model, corresponding to 2.6 days of stability, shows feasibility with future applications of these chemical markers.

RESUMO: As fitoalexinas são compostos que vêm sendo estudados há alguns anos, apresentando principalmente atividade antimicrobiana. As plantas da família Poaceae são as geograficamente mais difundidas e se destacam por sua importância econômica, uma vez que são os cereais que compõe a base da alimentação, em todos os continentes. Essa família se destaca por apresentar uma variedade de fitoalexinas, sendo que as mais importantes são sintetizadas a partir da via do ácido chiquímico. A caracterização desses compostos com atividade antimicrobiana é realizada por meio de técnicas cromatográficas, sendo que a cromatografia líquida de alta eficiência (HPLC) acoplada com espectrometria de massas é a técnica mais eficiente nesse processo. O trabalho apresenta como objetivo uma abordagem da função, caracterização, biossíntese e aplicações das fitoalexinas em plantas da família Poaceae.

ABSTRACT: Phytoalexins are compounds that have been studied a few years ago, which present mainly antimicrobial activity. The plants of the family Poaceae are the most geographically widespread and stand out for their economic importance, once they are cereals used as staple food. This family stands out for having a variety of phytoalexins, which can be synthesized via the shikimic acid (the phenylpropanoids), or mevalonic acid, being considered terpenoid phytoalexins. The characterization of these compounds with antimicrobial activity is carried out using chromatographic techniques, and the high-performance liquid chromatography (HPLC) coupled with mass spectrometry are the most efficient methods in this process. This research aimed to present an approach of the function, characterization and biosynthesis of phytoalexins in plants of the family Poaceae.