Comparison on the Compositions and Antioxidant Activity of Essential Oil from the Fruits of Phellodendron amurense Rupr. Under Four Different Picking Stage

Abstract

The chemical composition of the essential oils (EOs) from Phellodendron amurense Rupr. fruits in four different stages were analysed by GC-MS. Sixty-three compounds were identified. There were 35 mutual compounds existed in four various stages. Three constituents, which accounted for 38.15% of the EOs, were dominated by α-myrcene (20.27%), (±)-cembrene (11.24%) and Linalool (6.64%), followed by α-pinene, geranyl acetate, 2-undecanone, Geraniol, Germacrene and so on. In addition, the EOs of the third stage (III) exhibited a significant antioxidant activity in all conducted assays, with an IC50 value of 1.613 mg/mL, using 1, 1-diphenyl-2-picrylhydrazyl (DPPH) assay, 1.390 mg/mL in β-carotene/linoleic acid bleaching assay and 2.601 mg/mL in peroxide scavenging activity assay. Peroxide scavenging activity of the EOs at the third stage had significant difference from L-ascorbic acid (Vit C) as positive control, which showed antioxidant activity (IC50, 2.601 mg/mL) was almost two times stronger than Vit C (IC50, 5.213 mg/mL). While the other two assays in scavenging DPPH and β-carotene/linoleic acid bleaching assay had little significance with positive control. The resrults suggest that α-myrcene is one of the active ingredients responsible for the antioxidant activities of the EOs, but other chemical ingredients are also involved in regulating the biological actions of them. The results obtained are of availability for determining the most favorable time for picking fruits.