Essential oil composition and variability of Artemisia herba-alba Asso. growing in Tunisia: comparison and chemometric investigation of different plant organs

Abstract

This study was conceived to investigate the composition of four essential oils (EOs) extracted by hydrodistillation from four parts (leaves, stems, leaves/stems, roots) of Artemisia herba-alba growing wild in the center of Tunisia. Artemisia herba-alba aerial and roots parts were shade dried at room temperature with ventilation. The material was cut into small pieces and subjected to hydrodistillation using a Clevenger-type apparatus. The GC analyses were accomplished with a HP-5890 Series II instrument. A total of 152 compounds were characterized by GC and GC-MS, representing 91.3-99.7% of the total oil compositions. All four oils are dominated by monoterpene derivatives (68.2-99.5%) and the major volatile constituent was α-thujone (18.2-45.5%). Qualitative and quantitative differences between the four essential oils have been observed for some compounds. The main compounds of the essential oil from the leaves were α-thujone (45.5%), β-thujone (11.4%), trans-sabinyl acetate (10.1%), 1,8-cineole (7.4%) and camphor (6.8%). α-thujone (27.5%) was also the main compound in the essential oil of leaves/stems, followed by camphor (22.9%), 1,8-cineole (8.3%), β-thujone (8.2%) and camphene (5.6%). The essential oil of stems was dominated by α-thujone (28%) followed by β-thujone (11.4%) and chrysantenone (11%). In the essential oil of roots, α-thujone was less represented (18.2%), followed by camphor (14.6%) and curcumen-15-al (14.3%). Curcumen-15-al has been reported for the first time in Artemisia herba-alba oil and should be considered as a new chemotype. The results showed a variation in chemical compositions and yield of the EOs from Artemisia herba-alba. Curcumen-15-al is a new chemotype that was found in Artemisia herba-alba from Tunisia.