Chemical composition and antioxidant activity of the essential oil of Renealmia alpinia (Rottb.) Maas

Renealmia alpinia (Rottb.) Maas was collected in Serra do Tepequem, municipality of Amajari, state of Roraima, Brazil. The essential oil was obtained from the fresh leaves by hydrodistillation using a Clevenger apparatus and analysed using GC-FID and GC-MS. The oil provided a yield of 0.6% (w/w), which, in the analysis of its contents, presented a higher concentration of sesquiterpenes, with alpha-phellandrene (23.10%), 16-oxo-8(17),12(E)-labdadien-15-oic acid (17.05%), beta-caryophyllene (10.28%), valencene (5.27%) and allo-aromadendrene (3.52%) being the most abundant. The antioxidant activity of the essential oil was determined using two methods, and indicated significant activity by both. Using the DPPH method, the essential oil presented an IC50 of 1.470 +/- 0.0264 mg.L-1 and an inhibition of the beta-carotene/linoleic acid oxidation system of 76.43 +/- 0.80%.