Composition and Biological Activity of Essential Oils from Protium confusum

The composition and biological activity of the essential oils from leaves, fruits, sterns and bark of Protium confusum are reported for the first time. Forty-six to sixty-three constituents were identified ranging from 73.8% to 98.5% of the samples. Limonene (60.2%) was the main component in the fruit oil, whereas spathulenol (19.3%), beta-caryophyllene oxide (14.1%) and P-caryophyllene (8.0%) reached the highest percentages in the oil from leaves. The volatile oils from bark and sterns showed tile same major constituents: p-cymen-8-ol (14.4% and 6.1%, respectively), spathulenol (9.5% and 9.0% respectively), and hexadecanoic acid (8.4% and 7.8%, respectively). The composition of the essential oils differed significantly from those of previously investigated Protium species. Three out of the four samples exhibited antibacterial activity against Slaphylococcus aureus and Mycobacterium smegmatis, the one from leaves being the most active, with MIC values of 62.5 mu g/mL in both cases. No activity against Candida albicans was detected. The bark oil showed the highest larvicidal activity against Aedes aegypti (LC100 = 125 mu g/mL).