Green Extraction of Volatile Terpenes from Artemisia annua L

In the present study, the extraction of volatile terpenes from A. annua with supercritical CO2 (sc-CO2) was optimized by a full factorial design procedure and compared with conventional distillation. The influence of pressure (100–220 bar) and temperature (40–60 °C) on sc-CO2 extraction was investigated to obtain extracts rich in the desired components while maintaining a high yield. Extraction yields (m/m) varied from 0.62% (130 bar/40 °C) to 1.92% (100 bar/60 °C). Monoterpenes were the most abundant constituents of the sc-CO2 extracts, among which artemisia ketone (16.93–48.49%), camphor (3.29–18.44%) and 1,8-cineole (4.77–11.89%) dominated. Arteannuin B (3.98–10.03%) and β-selinene (1.05–7.42%) were the major sesquiterpenes. Differences were found between the terpene profiles of the sc-CO2 extracts and the essential oils obtained by conventional hydrodistillation and steam distillation, as well as between the distilled essential oils. Our results demonstrate the optimal conditions for the rapid and effective supercritical extraction of certain monoterpenes and sesquiterpenes from A. annua, which have promising antimicrobial, antioxidant, antiviral, anti-inflammatory and antitumor properties.