Essential oil composition, antioxidant capacity and antifungal activity of Piper divaricatum

The major components of the essential oil of Piper divaricatum from Marajó Island, PA, Brazil, were methyleugenol (63.8%) and eugenol (23.6%), which were identified by GC and GC-MS. Essential oils of Piper species from the Brazilian Amazon are rich in either mono- and sesquiterpenes or phenylpropanoids, as seen in this study. The oil was able to scavenging the DPPH radical, displaying an inhibition varying from 19% to 74%, with an EC50 value of 16.2 +/- 1.9 microg mL(-1). In the bleaching of beta-carotene, the inhibition of the oil oxidation was 60.0 +/- 2.7%. The oil gave minimum inhibitory concentrations for the fungi Cladosporium cladosporioides and C. sphareospermum of 0.5 microg and 5.0 microg, respectively. The oil also showed significant brine shrimp larvicidal activity (LC50, 38.8 +/- 0.8 microg mL(-1)).