Wild, greenhouse-acclimatized and tissue culture-derived plants
were seperated into aerial and underground parts, freeze-dried and
lypholized. The ground materials (100 mg/mL) were homogenized
with 80% methanol in a 2 mL Eppendorf, using an oscillation ball
mill (MM 301, Retsch, Haan, Germany) at a frequency of 27 l/s for
3 min. The resultant extracts were centrifuged for 10 min at 20
000 rpm and the supernatant was retained for subsequent analysis.