Essential oils of three taxa of the Nepeta argolica aggregate from Greece

Abstract

The essential-oil composition of three not previously studied taxa belonging to the Nepeta argolica aggregate was examined. The oils of N. argolica ssp. malacotrichos and N. argolica ssp. vourinensis (both Greek endemics) are rich in 1,8-cineole (30.9-55.6% of the total oil composition), while those of the Balkan endemic N. spruneri are rich in either sesquiterpenes (mainly caryophyllene oxide, 14.6-19.8%) or in 4aα,7α,7aβ- and 4aα,7α,7aα-nepetalactones (total content 17.5-40.5%), accompanied by caryophyllene oxide (11.5-11.7%) and 1,8-cineole (up to 16.5%). The comparison of our results with published information concerning the related taxa of the N. argolica aggregate showed that while oils with as main components nepetalactones or 1,8-cineole are common, sesquiterpene-rich oils are reported for the first time within the aggregate.