Optimization of Baccharis punctulata volatile oil isolation extraction for enhanced yield of trypanocidal compounds

Abstract

This study examines how storage conditions affect the volatile oil composition of Baccharispunctulata, to enhance the yield of trypanocidal sesquiterpenes. Oils extracted from fresh leavesand inflorescences appear yellow, while those extracted from stored material turn green, primarilydue to guaiazulene formation. Short drying periods enhance yields of shyobunone and verbocci-dentafuran (15.33% and 10.93%, respectively), while longer storage times reduce these com-pounds, and increase oxidation products such as caryophyllene oxide and spathulenol. Femaleplants in the flowering stage are the best source, with a 4-h hydrodistillation yielding optimalresults. In biological assays of the isolated oil components, caryophyllene oxide showed thehighest trypanocidal activity (IC50 = 1.62 μg/mL, SI = 45.28), followed by spathulenol (IC50 =15.91 μg/mL), verboccidentafuran (IC50 = 20.71 μg/mL) and shyobunone (IC50 = 30.28 μg/mL).These findings emphasize the need to identify the best source and to refine isolation methodsto obtain pure compounds that ensure reproducible trypanocidal activity.