Essential oil of two chemotypes of Mentha suaveolens during ontogenesis

The composition of the main constituents of the essential oil of two different chemotypes of Mentha suaveolens has been investigated during development. In the first chemotype (6) a definite increase of 1,2-epoxymen-thylacetate was observed, but piperitone oxide was always the main constituent. In the second chemotype (12) an increase of neo- and dihydrocarveol and their corresponding acetates was observed and dihydrocarvone was the main constituent. The results have been used to formulate a new biosynthetic scheme for the cyclic oxygenated monoterpenes found in essential oils of the genus Mentha.