Flavouring ingredient Piperitone is a natural monoterpene ketone which is a component of some essential oils. Both stereoisomers, the D-form and the L-form, are known. The D-form has a peppermint-like aroma and has been isolated from the oils of plants from the genera Cymbopogon, Andropogon, and Mentha. The L-form has been isolated from Sitka spruce. (Wikipedia)