Characterization of volatile compounds in <i>Eugenia uniflora</i> L. essential oil by GC×GC/TOFMS: exploring its antioxidant potential and <i>in vitro</i> ocular irritation assessment

The specie of Eugenia uniflora L., commonly known as Pitanga, is a tree from the Myrtaceae family widely distributed in Brazil and South American. Presents recognized ethnopharmacological activities, mainly due to leaves essential oil (EO). However, few studies have investigated the correlations between composition and biological activities, all of them using one-dimensional gas chromatography (GC/MS). This study discusses the chemical composition of pitanga OE by GC×GC/TOFMS, in vitro antioxidant activity (DPPH and ORAC assay), and in vitro ocular irritation using Hen’s Egg Test-Chorioallantoic Membrane (HET-CAM). 89 compounds were identified by GC×GC/TOFMS, more than the usual in literature by GC/MS, including selina-1,3,7(11)-trien-8-one epoxide (20.09%) a marker of this specie. Isospathulenol, dimethyl-bicyclo[octanone]-diisopropylidene, 14-oxi-α-muurolene, 2-α-acetoxy-amorpha-4,7(11)-dien-8-one were also found. OE’s DPPH and ORAC assays showed 95.5/mL and 685.6 μmol TE/g, respectively, while HET-CAM assay showed non-ocular irritating potential. Therefore, one can consider this study to be the most complete involving pitanga essential oil.