major constituents, antioxidant and antibacterial activities of zanthoxylum armatum dc. essential oil

chemical compositions, antioxidant and antibacterial activities of zanthoxylum armatum essential oil was analyzed. a total of 3 samples (500 g/each) were collected 6:00 am; 12:00 noon; and 6:00 pm in the same day. the essential oil was extracted by hydro distillation in clevenger apparatus and their chemical compositions were determined by the gc-ms system. the eleven most abundant ingredients were bornyl acetate (16.61-22.66%), cymene (8.25-12.50%), ?-copaene (7.54-7.59%), ?-terpinene (5.33-7.66%), camphene (4.32-4.66%), limonene (2.66-4.68%), linalool (3.28-3.58%), ?-ocimene (3.24-3.36%), trans -caryophyllene (2.54-3.46%), ?-terpinolene (2.32-3.36%) and germacrene (2.02-2.85%). antioxidant activity was examined by 2,2'-diphenyl-1-picrylhydrazyl (dpph) radical scavenging method. ascorbic acid was used as standard. essential oil exhibited significant antioxidant activity. the ic 50 of the oil was found 27.0± 0.1 ?g/ml and that of ascorbic acid 15.0± 0.5 ?g/ml. essential oil of z. armatum also exhibited moderate antibacterial activity. the results showed that the gram-positive bacteria are more sensitivity to the essential oil than gram negative bacteria.