GAS–LIQUID CHROMATOGRAPHY OF TERPENES: XV. THE VOLATILE OIL OF MENTHA ARVENSIS VAR. GLABRATA RAY

Abstract

The volatile oil of the North American wild mint Mentha arvensis L. var. glabrata was found to consist mainly of d-pulegone (80-90%) and smaller amounts of [alpha]-pinene, [beta]-pinene, sabinene, limonene, 1,8-cineole, 1-octen-3-ol, menthone, isomethone, piperitone, cis- and trans-pulegone oxide, and piperitenone. Trace amounts of [gamma]-terpinene, menthofuran, [beta]-caryophyllene, and [epsilon]-, [delta]-, and [gamma]-cadinene were also isolated, and camphene, p-cymene, terpinolene, sabinene hydrate, isopulegone or its steroisomer, [beta]-elemene, and a-terpineol were tentatively identified. A labile autoxidation product of pulegone was also detected. A study of the seasonal variations in the oil composition showed that significant changes in the quantiative composition occurred only in very young plants. The maximum yield of oil was obtained at the start of flowering. Practically no variation in the composition of the oil was recorded for plants from different localities.