Gas chromatographic-mass spectrometric characteristics of essential oils of plants of the genus Pycnanthemum (Lamiaceae) and peculiarities of their application in practice

Abstract

Background. Not all plants are capable of producing essential oil (EO). There are 3.000 different plant EOs described in the world, but only 10 % of them are widely used by humans. In particular, perfumery and the food industry use the largest amount of natural EOs – 30 % and 40 % of the world production, respectively. A thorough study of EOs, knowledge of their components in both chemical and pharmacological sense will facilitate the improvement of the quality of human life. The purpose of our experimental study was to determine the EO potential of four species of the genus Pycnanthemum Michx. (Lamiaceae): P. montanum Michx., P. muticum (Michx.) Pers., P. tenuifolium Schrad., P. verticillatum var. pilosum (Nutt.) Cooperr. introduced in the forest-steppe zone of Ukraine. The above plants are representatives of the flora of North America. Methods. The EOs were obtained in laboratory conditions by hydrodistillation using a Clevenger apparatus. The raw material of the plants – a blended mass of leaves, inflorescences and the herbaceous part of the stem was used in an air-dry state. Harvesting of raw materials was carried out during the flowering phase of plants. The EOs content is given in terms of an absolute dry weight. The identification of compounds and their amount in each EO was determined by the method of gas chromatography-mass spectrometry. Results. In the conditions of the forest-steppe of Ukraine, the introduced species of plants of the genus Pycnanthemum show a high level of EOs biosynthesis – 0.53–3.34 %. The dominant compounds common to the obtained essential oils are Pulegone, Isomenthone, and Isopinocamphone. The indicators of the content of pulegone exceed those of other compounds and reach 48.14–73.93 %. Pulegone is a controversial organic compound, since it exhibits a high biological activity and possesses pharmacological properties suitable for use in medical practice, but when cleaved, it forms toxic metabolites, in particular mentofuran. Conclusions. The obtained results indicate that plants of the genus Pycnanthemum, which are little known in Ukraine, have a high EO potential under the proposed growth conditions. Due to this, they are potential objects for use in domestic cultural phytocenoses. Considering the component composition of EOs with the dominant Pulegone, their consumption requires correct dosage.