Comparison of chemical composition of the essential oil from Marrubium vulgare L. and M. incanum Desr. during the second year of cultivation

Horehound herb (Marrubium vulgare L.) is harvested from plantations in Poland. In our country, there are also favorable conditions for M. incanum Desr. growing. The aim of the study was to compare the chemical composition of essential oils from M. vulgare L. and M. incanum Desr. in the second year of cultivation. The study revealed the presence of 31 compounds in the essential oil from M. vulgare L. and 24 compounds in the essential oil from M. incanum Desr. Chromatographic analysis revealed that the main compounds in the essential oil of M. vulgare L. from a two-year plantation were as follows: E-caryophyllene (34.51–36.78%), germacrene D (22.45–27.18%), bicyclogermacrene (9.54–11.12%), δ-amorphene (6.15–8.18%), and carvacrol (4.71–6.64%), whereas the following compounds prevailed in the oil from M. incanum Desr.: germacrene D (28.75–32.14%), E-caryophyllene (23.18–29.57%), α-cadinol (13.59–20.84%), and carvacrol (2.08–7.47%)