A mass of 200 mg of dry plant material was extracted three times with 3 mL of ethyl acetate (Fisher Chemicals, Reinach, Switzerland) in an ultrasound bath (30 minutes). The total solvent volume (c.a. 9 mL) was filtered through a paper filter and dried under an N2 flux. The residue was dissolved in methanol (2 mL) and passed through a pre-conditioned (according to the manufacturer) C18 SPE cartridge (1000 mg). The filtrate and the following washing (1 mL of 1:1 MeOH:EtOAc) were collected in the same vial. The solvent was dried under an N2 flux. The enriched extract was solubilized in DMSO (Sigma, St Louis, USA) to achieve a concentration of 5 mg/mL. See Figure .