Essential oils with 1,2-epoxy-p-menthane derivatives from Mentha spicata plants growing across the Island of Crete

Abstract

The essential oil content and composition of Mentha spicata plants, collected from 11 localities, scattered across the island of Crete (S. Greece), have been studied. The qualitative and quantitative essential oil analyses by means of GC and GCMS, have shown that these are characterized by a high quantity of trans-piperitone oxide and/or piperitenone oxide. The pattern of essential oil quantitative variation follows a NW → SE direction on Crete. Along this direction, the total essential oil content of the plants increased whereas, the essential oil components formed via the pathway leading to the formation of cis-piperitone oxide are gradually substituted by those leading to the formation of trans-piperitone oxide.