*2.1. Plant Material and Growing Conditions*

*Sideritis perfoliata* seedlings with 3–4 established leaves were purchased from the Cypriot National Agricultural Department and grown using an organic farming cultivation protocol. Plants were grown in a silt loam soil (6.76% clay, 39.2% sand and 54% silt) with organic matter of 3.02%, pH of 8.42, Electrical Conductivity (EC) of 0.85 mS/cm, and CaCO3 of 21.23%, allowing the seedlings to grow for 2.5 months. The plantation was fully irrigated with no pesticides or chemicals being applied during the growing period. Weeds were removed manually or mechanically. Above ground (~5 cm) plant material (~10 kg) including leaves, stems and flowers, was collected during spring at the early flowering stage and raw material processed in the lab.
