Study of qualitative and quantitative changes in Nepeta crispa Willd. essential oil in natural habitats and agronomical conditions

Nepeta crispa Willd. Locally known as Mofarrah belongs to Lamiaceae family. It is an Iranian endemic self-growing medicinal plant to Alvand Mountains in Hamadan province. N. crispa has carminative, anti-inflammatory, antinociceptive, antibacterial and antifungal properties. The aim of this study was to investigate the phytochemical composition of essential oil compounds of this plant in the vegetative stage, which cultivated in Tarbiat Modares University of Tehran at an altitude of 1283 m above sea level, and compare with samples taken from natural habitats in Arzanfood and Gashani with the altitude of 3015 and 2489 m above sea level, respectively. The plants were harvested during the late July 2018. The essential oils of all samples were obtained by hydrodistillation and were analyzed by GC-MS and GC-FID. The yield of essential oil in the sample collected from Arzanfood, Gashani and field samples were 2.13, 1.97 and 0.55% (w/w), respectively. Twenty components were identified among the samples, representing 93-96% of the oils. The main components were 1, 8-cineole (40.25%, 48.5, 49.9%), 4aα, 7β, 7aα-nepetalactone) 34.8%, 3.7%, 24.7%) and β- pinene) 6.2%, 5.4%, 5.4%) for cultivated field, Gashani and Arzanfood samples, respectively. Although the percentage of oil and 1, 8-cineole in the cultivated sample were low, but the amount of nepetalactome compounds was high. According to the results, the environmental conditions had an important role in the qualitative and quantitative changes in the essential oil of this plant but cultivation of N. crispa in a place with more than 1200 m difference in altitude, lower than the main habitat, was a promising sign for domestication of N. crispa. Optimization of other factors including, cultivation in an area close to the natural habitat, nutrition, biotic and abiotic stresses treatment could even improve the quality of this plant compared to the self-growing ones.