3.1. Plant Material and Essential Oil Extraction

Six plants were chosen for this study. Four plants belonging to the Lamiaceae family; Origanum compactum, Mentha spicata, and Thymus serpyllum collected in August 2012, and Origanum majorana in February 2012. One myrtaceae (Myrtus communis) collected in August and one astraceae (Artemisia herba-alba) in July. All plants are from Taounate region (Morocco). A voucher specimen of each plant was deposited at the herbarium of the National Agency of Medicinal and Aromatic Plants (NAMAP), Morocco. To obtain essential oils, the fresh aerial part (leaves and stems) of each plant were subjected separately to hydrodistillation for 3 h using a Clevenger apparatus. The obtained essential oils were stored at 4 °C in dark until use.