Almost all aromatic plants are also medicinal plants and the volatiles contribute to their medicinal properties. Essential oils are complex mixtures of monoterpenes and phenylpropanes and their analysis is mainly performed via gas chromatography and mass spectrometry.

• Mountain tea

The "mountain tea" (herb of different Sideritis taxa) that is frequently consumed as an infusion in Greece, is the subject of studies of its composition and its neuroprotective action. At present, we are developing efficient methods (among them ultrasound-assisted extraction with organic solvents after treatment of the dried herb material with enzymes) for the GC-MS analysis of its essential oil and compare them to the classical Clevenger hydrodistillation, since this plant gives a low yield of essential oil. We apply this methodology to the monitoring of the composition of different indigenous and cultivated Sideritis taxa.

• Common and Greek sage

We have developed and validated GC-MS methods for the study of essential oils of different populations of Salvia officinalis, Salvia fruticosa and Salvia pomifera. Moreover, we are monitoring the essential oil content of wild plants cultivated in the Botanical Garden throughout the year.