Composition of Free and Glycosidically Bound Volatiles of Mentha aquatica L.

Free and glycosidically bound volatiles of mentha aquatica L. were investigated. Free volatile compounds were isolated from the dried plant material by hydrodistillation and glycosides by extraction with water during hydrodistillation. Free volatile compounds (essential oil) as well as the aglycones obtained after the hydrolysis of glycosides were analyzed by gas chromatography-mass spectrometry (GC-MS). The essential oil was composed of monoterpene hydrocarbons (10.47%), sesquiterpene hydrocarbons (20.09%) and oxygen containing compounds (68.42%). The major components of the essential oil were: menthofuran (3978.08 mg kg-1), 1,8-cineole (1716.44 mg kg-1) and trans-caryophyllene (1109.20 mg kg-1). After enzymatic hydrolysis, the major volatile aglycones were: 1-octen-3-ol (30.22 mg kg-1), eugenol (10.21 mg kg-1), 2-phenylethanol (6.81 mg kg-1), 3-hexen-1-ol (5.35 mg kg-1), perilla alcohol (4.13 mg kg-1), 1-hexanol (3.58 mg kg-1), and 3-octanol (2.44 mg kg-1). Moderate similarity was found between volatile aglycones and the corresponding free volatiles in the essential oil. Acidic hydrolysis, after enzymatic hydrolysis, liberated additional amounts of aglycones. Approx. 38% of the glycosides were not hydrolyzed by the used enzyme