Influence of growth phase on the essential oil composition ofZiziphora clinopodioidesLam.

Ziziphora clinopodioides belongs to the Lamiaceae family, that are widespread all over Iran. The leaves, flowers and stems of the plant are frequently used as wild vegetables or additives in food to offer aroma and flavour. The chemical composition of the essential oils obtained from the aerial parts of Z. clinopodioides Lam. in different growth stages were analysed by GC and GC-MS, and 29 components were identified. Pulegone (30.1%), thymol (21.3%), p-mentha-3-en-8-ol (12.9%) and piperitenone (9.3%) were the main components in the pre-flowering stage. In the flowering stage, pulegone (44.6%), p-mentha-3-en-8-ol (10.5%), 1,8-cineoil (10.4%), piperitenone (8.7%) and thymol (6.7%) were identified as the main constituents and in the post-flowering stage, pulegone (41.3%), isomenthone (11.6%), p-mentha-3-en-8-ol (11%), p-mentha-3,8-diene (7.2%) and thymol (5.8%) were identified as the major components.