The powders obtained (1 g) were extracted 3 times in a solvent
mixture (100 mL the first time, 50 mL the next two times) comprising
methanol/water (70:30, v/v) using a Brinkmann homogenizer
(Polytron-Kinematica GmbH, Kriens-Luzern), at moderate speed for
1 min, while cooled in ice