Renealmia thryrsoidea (Ruiz & Pav.) Poepp. & Endl is a plant used by the Amazonian indigenous people of Ecuador for its various medicinal properties. Its leaves exhibit a remarkable aroma with a hint of spiciness. The essential oil extracted from its leaves was analyzed by GM/MS, using two systems with columns of different polarity, in both was confirmed the presence of terpinolene (26.32%), α-felandrene (17.16%), γ-terpinene (6.55%), β-pinene (5.97%) and p-cymol (4.70%). Free radical scavenging activity was analyzed through 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) spectrophotometric methods ; by applying ABTS method , the activity was comparable to that of the essential oil of Thymus vulgaris. The trials of antimicrobial activity show a strong inhibition against Gram negative bacteria as Escherichia coli and Pseudomonas aeruginosa.
Key words: Renealmia thryrsoidea, essential oil, DPPH, ABTS, minimum inhibitory concentration (MIC).