Chemical Composition and Biological Activity of Nepeta parnassica Oils and Isolated Nepetalactones

Abstract

Essential oils of Nepeta parnassica, collected at different developmental stages, were analyzed by means of GC/MS. From the fifty-five identified constituents in samples A and B, representing 94.8% and 98.7% of the oils respectively, 4aα,7α,7aβ-nepetalactone (22.0%), 1,8-cineole (21.1%), α-pinene (9.5%) and 4aα,7β,7aβ-nepetalactone (7.9%) were the major components of sample A (vegetative stage), whereas in sample B (flowering stage) the main contributors were 1,8-cineole (34.6%), 4aα,7α,7aα-nepetalactone (17.3%), α-pinene (11.4%) and 4aα,7α,7aβ-nepetalactone (8.9%). The oils were tested on human health important insects such as the Pogonomyrmex sp. ants and the Culex pipiens molestus mosquitoes with promising results on insect repellency/toxicity.