Studies On Essential Oils Extracted From Two Plants Of Artemisia And Antimicrobial And Antioxidant Activities Of The Essential Oils

Artemisia scoparia Waldst et kit and Artemisia sphaerocephala Krasch are belonged to Artemisia of Compositae, which are abundant in Inner Mongolia. Steam Distillation (SD) and Supercritical CO₂ Fluid Extraction (SCFE-CO₂) were applied to extract essential oils from Artemisia scoparia Waldst et kit and Artemisia sphaerocephala Krasch. It was done to obtain the optimal condition extracting essential oils from Artemisia scoparia Waldst et kit and Artemisia sphaerocephala Krasch by steam distillation, and the effects of material diameter, the ratio of material to water and distillation time were discussed. The result showed that the optimal technological parameters were: 0.3mm, 1∶13 and 5h,and the order of different effect factors on extraction amount was material diameter>distillation time>the ratio of material to water. The extraction rates of Artemisia scoparia Waldst et kit and Artemisia sphaerocephala Krasch were respectively 0.34% and 0.37%. It was done to obtain the optimal condition extracting essential oils from Artemisia scoparia Waldst et kit, Artemisia sphaerocephala Krasch and the seeds of Artemisia sphaerocephala Krasch by supercritical CO₂ fluid extraction, and the effects of extract pressure, temperature and time were discussed. The result showed that the optimal technological parameters were: 30MPa, 50℃and 3h, and the order of different effect factors on extraction amount was extract pressure>temperature>time. The extraction rates of Artemisia scoparia Waldst et kit , Artemisia sphaerocephala Krasch and the seeds of Artemisia sphaerocephala Krasch were respectively 3.2%, 3.5% and 11.2%.The five kinds essential oils had strong inhibition on microbial activities. The essential oil of Artemisia scoparia Waldst et kit had the strongest inhibition on Staphylococcus aureus, the weaker inhibition on Escherichia coli, Listera monocytogenes, Bacillus subtilis and Aspergillus niger. The essential oil of Artemisia sphaerocephala Krasch had the strongest inhibition on Escherichia coli, the weaker inhibition on Staphylococcus aureus, Listera monocytogenes, Bacillus subtilis and Aspergillus niger. The essential oil of the seeds of Artemisia sphaerocephala Krasch had the weaker inhibition than the essential oils of Artemisia scoparia Waldst et kit and Artemisia sphaerocephala Krasch. The essential oils extracted by supercritical CO₂ fluid extraction had the stronger inhibition microbial activities the essential oils extracted by steam distillation.The antioxidant activities in vitro of the five kinds essential oils were studied by DPPH·method. It was found that the five kinds essential oils had antioxidant activity, the larger the concentration, the stronger the antioxidant activity. The scavenging rates of the two kinds essential oils of Artemisia scoparia Waldst et kit of 5.12g/L were respectively 91.65% (SCFE-CO₂) and 77.15% ( SD) in 8 minutes. The scavenging rates of the two kinds essential oils of Artemisia sphaerocephala Krasch of 5.12g/L were respectively 92.33% (SCFE-CO₂) and 47.25% (SD) in 8 minutes. The scavenging rate of the essential oil of the seeds of Artemisia sphaerocephala Krasch by supercritical CO₂ fluid extraction of 5.12g/L was 72.18% in 8 minutes. GC-MS was applied to analyze the components of extracted essential oils. Components of essential oils extracted by the two methods varied, only 3 components in common for Artemisia scoparia Waldst et kit and 2 components in common for Artemisia sphaerocephala Krasch.