Antioxidant activities and chemical composition of essential oil of Pistacia atlantica from Algeria

A total number of 34 samples of leaves of Pistacia atlantica Desf. collected randomly from four different locations in Algeria were submitted to hydrodistillation. The essential oils obtained at a yield range of 0.02–0.12% (v/w) were screened for theirs antioxidant activities in vitro using two different and complementary assays: the DPPH
• (2,2-di-phenyl-1-picrilhydrazyl) free radical scavenging and the FRAP (Ferric Reducing Antioxidant Power). The result of the DPPH assay gives an IC50 range value of (8.8–27.48) mg/mL for all the samples studied. BHA (butylated hydroxyanisole), BHT (butylated hydroxytoluene) and ascorbic acid were used for comparison purposes. The FRAP antioxidant activity test of the oil was expressed using ascorbic acid as standard reference antioxidant. Others synthetic antioxidants were used for comparison. The antioxidant expressed as Ascorbic acid Equivalent Antioxidant Capacity (AEAC) has a range value of (2.8–11.1) mg/mL, i.e. that the sample oils are almost 3–11 times much more active than ascorbic acid. The essential oils were analyzed by GC and GC–MS. The essential oil was rich in monoterpenes and oxygenated sesquiterpenes. Forty-seven compounds were identified. The main compounds were not the same in the all analysed samples. The percentages ranges of the major components identified from the different locations were α-pinene + α-thujene (5.54–66.61%), camphene (0.75–20.85%), β-pinene (1.09–13.12%), p-cymene (0.39–10.19%), terpinen-4,ol (0.42–15.97%) and spathulenol (0.46–32.64%).