Chemical Composition, Enantiomeric Distribution, and Antifungal Activity of the Oleoresin Essential Oil of Protium amazonicum from Ecuador

Resumen

<b>Background:</b><i>Protium</i> species (Burseraceae) have been used in the treatment of various diseases and conditions such as ulcers and wounds. <b>Methods:</b> The essential oil from the oleoresin of <i>Protium amazonicum</i> was obtained by hydrodistillation and analyzed by GC-MS, GC-FID, and chiral GC-MS. <i>P. amazonicum</i> oleoresin oil was screened for antifungal activity against <i>Candida albicans</i>, <i>Aspergillus niger</i>, and <i>Cryptococcus neoformans</i>. <b>Results:</b> A total of 54 components representing 99.6% of the composition were identified in the oil. The essential oil was dominated by δ-3-carene (47.9%) with lesser quantities of other monoterpenoids α-pinene (4.0%), <i>p</i>-cymene (4.1%), limonene (5.1%), α-terpineol (5.5%) and <i>p</i>-cymen-8-ol (4.8%). Chiral GC-MS revealed most of the monoterpenoids to have a majority of <i>levo</i> enantiomers present with the exceptions of limonene and α-terpineol, which showed a <i>dextro</i> majority. <i>P. amazonicum</i> oleoresin oil showed promising activity against <i>Cryptococcus neoformans</i>, with MIC = 156 μg/mL. <b>Conclusions:</b> This account is the first reporting of both the chemical composition and enantiomeric distribution of the oleoresin essential oil of <i>P. amazonicum</i> from Ecuador. The oil was dominated by (-)-δ-3-carene, and this compound, along with other monoterpenoids, likely accounts for the observed antifungal activity of the oil.