The essential oil and glycosidically bound volatile compounds of Calamintha nepeta (L.) Savi

Results of the investigation of the essential oil and glycosidically bound volatile compounds of Calamintha nepeta (L.) Savi are presented in the paper. The essential oil was isolated by hydrodistillation and glycosides were extracted with ethyl acetate. The yield of essential oil was W = 0.91%. The essential oil was fractionated on a microcolumn with solvents of different polarity. One fraction of terpene hydrocarbons and four fractions of oxygenated terpene compounds were obtained. All fractions were analyzed by gas chromatography-mass spectrometry (GC-MS) on two columns with different polarity of the stationary phases. The purpose of the fractionation was to obtain a more completely analysis. In this way, sixty-five compounds were identified. In contrast, only twenty-four compounds were identified in the essential oil without fractionation. The main components were piperitone oxide, piperitenone oxide, limonene, caryophyllene, thymol, linalool, S-octanol and other compounds in smaller amounts. After isolation, final purification of the glycosides by >>flash<< chromatography on silicagel column and enzymatic hydrolysis, the liberated aglycones were analyzed in the same way as the essential oil fractions. The content of volatile aglycones was W = 0.00081% or 8.1 mg kg(-1) of the plant material. Eighteen compounds were identified. The main aglycones were eugenol, carveol, 3-octanol, 3-hexene-1-ol, 2-butanol, 2-phenylethanol, methyl salicylate, benzyl alcohol, acetophenone derivates, and others. Some of the aglycones were the same or structurally similar to the essential oil components. Glycosidically bound volatiles in this plant have not been investigated so far.