Effect of Geographic Location, Ontogenesis on Essential Oil Composition and Spontaneously Emitted Volatile Organic Compounds of Inula viscosa (L.) Greuter. (Astraceae) Grown in Jordan

The present study aimed at investigating the variation in the chemical composition of emitted volatile organic compounds (VOCs) and essential oils obtained from fresh aerial parts of Inula viscosa (Asteraceae) as affected by growth stage and geographical location zone. VOCs were extracted by solid phase microextraction (SPME) method from whole aerial parts of I. viscosa during the vegetative (spring-August) period, and from fresh leaves, closed pre-flowering buds and fully expanded flowers during the full flowering season (October). The essential oils were extracted by hydrodistillation form fresh organs during the flowering stage. GC/MS analysis of VOCs during the vegetative period revealed sesquiterpene hydrocarbons as main components in the samples collected from the Mediterranean zone (MID-1: 64.72-27.48%, MID-2: 32.09-76.77%). The profile of the samples from the Irano-Turanian zone (IT) was quite different. Myrcenol was the main component in the leaves, pre-flowering buds and fully expanded flowers from all locations (0.61-39.01%). E-nerolidol was the main component in the hydrodistilled oil of all organs from the different locations (73.72-88.66 %). Principle component and cluster analysis revealed that the chemical composition of the essential oils and VOCs belonging to MID-zone were similar and quite different when compared to the composition of the samples belonging to IT-zone. The results indicated the possible use of E-nerolidole as a stable chemotype marker in I. viscosa taxonomy.