Essential oil composition of Pistacia lentiscus L. and Myrtus communis L.: Evaluation of antioxidant capacity of methanolic extracts

The seasonal variation of the essential oil composition, the antioxidant activity (DPPH, FRAP assays) and the total phenolic content (Folin-Ciocalteu assay) of two aromatic wild plants, Pistacia lentiscus L. (Anacardiaceae) and Myrtus communis L. (Myrtaceae), grown in Zakynthos, a Greek island, was investigated. The essential oil was obtained by hydrodistillation and subsequently analysed by GC–MS.The essential oil composition of P. lentiscus L. was characterised by a high monoterpene hydrocarbon fraction (45.0–68.3%), which was found in greater amounts during the flowering stage (May). At the same stage, the extracts showed the highest free radical-scavenging activity (IC50 = 5.09 mg/l) and antioxidant capacity (131 mmol/l), as well as the highest phenolic content (588 mg gallic acid/g plant material). The strongest antioxidant activity and the highest phenolic content for M. communis L. were obtained during full flowering stage (August). Its essential oil composition was characterised by a high oxygenated monoterpene fraction (70.1–73.2%), the highest accumulation of which was also observed during the same flowering stage.