GC-MS ANALYSIS OF THE ESSENTIAL OIL OF SATUREJA SUBSPICATA BARTL. EX VIS. OF MOLDOVAN ORIGIN

For the fi rst time the results of GC-MS analysis of Satureja subspicata L. oil of Moldovan origin are reported. The chemical profi le includes forty-four constituents and consists mostly (97.86%) of phenolic monoterpenes, monoterpene hydrocarbons, bicyclic sesquiterpenes and their oxygenated derivatives. A substantial quantitative and qualitative chemical differentiation of S. subspicata oil of Moldovan origin and reported oil of Croatian origin were found. The essential oil of S. subspicata L. plants cultivated in Republic of Moldova belongs to the carvacrol chemotype.


Introduction
Numerous studies have been conducted on Satureja L. species, growing in different world regions, particularly on its volatile oil composition. According to these data, essential oils from Satureja species have a very complex composition, which includes phenolic monoterpenes, monoterpene hydrocarbons, bicyclic sesquiterpenes, other terpene derivatives and fl avonoids [1][2][3][4].
The present studies are related to Satureja subspicata Bartl. ex Vis. cultivated in the Botanical Garden (Institute) of Academy of Science of Moldova (ASM), Collection of Medicinal Plants. Climate of the Republic of Moldova is favourable for S. subspicata, where plants have normal growth rhythms and successfully attain the generative period.
Up to date a few reports on essential oil composition and biological activity of S. subspicata species have been published. The volatile oil of S. subspicata possesses a big part of activities mentioned before, and is therefore a potential source of antimicrobial ingredients for the food and pharmaceutical industry.
The aim of this work is to reveal the chemical composition of S. subspicata essential oil cultivated in climatic and soil conditions specifi c for Republic of Moldova by means of GC-MS analysis.

Materials
The plant material Satureja subspicata of Moldovan origin (aerial parts with infl orescence) for the chemical analyses was collected during fl owering stage in July 2016 from experimental fi elds of the Botanical Garden (Institute) of ASM. The plants were cultivated in ecological conditions and without fertilizer use. Voucher specimen is deposited in the Herbarium of the Botanical Garden (Institute) of ASM.

Methods
Essential oil of S. subspicata was obtained by hydrodistillation (600 mL) of the aerial parts of the plant (200 g) for 2 hours in a Clevenger apparatus. After phase separation, volatile oil was dried over anhydrous sodium sulphate, and then used for chromatographic measurements.
Another team of researchers reported α-pinene (24.2%) as main compound of the essential oil from wild-grown S. subspicata in the Mediterranean part of Croatia, while carvacrol constitutes only 2.7% [14]. The S. subspicata species originating from Bosnia and Herzegovina contain thymol (28.6%) and carvacrol (27.9%) as main compounds of their essential oils [15]. The list of secondary components of essential oils of Moldovan and Croatian origin, correspondingly, is comparable but differs quantitatively and includes: α-pinene, limonene, α-terpinene, thymol, linalool, β-myrcene, limonene, geraniol and others. In contrast with essential oil of Croatian origin, the studied by us oil is characterized by high content of unreported before components like γ-terpinene, (E)-and (Z)-citral, β-bisabolene, nerol, β -caryophillene, germacrenes (B and D) and others. As a result, biological activity, pharmaceutical and perfumery value of S. subspicata oil of Moldovan origin can be much higher.

Conclusions
The quantitative and qualitative chemical differentiation of essential oil obtained from S. subspicata plants growing in Moldova and Croatia can be correlated with different geographic location and ecological conditions. The high content of the phenolic terpene carvacrol as a main component (47.56%) suggests that S. subspicata plants cultivated in Republic of Moldova belong to a new high yielding carvacrol genotype.