dried materials were powdered and kept in a desiccator, in the dark.
Samples Preparation. For the identification of phenolic compounds
ca. 0.15 g of leaves and stems and ca. 0.01 g of petals were thoroughly
mixed with 1.5 and 1 mL of methanol:water (1:1), respectively. To
check for possible anthocyanins in petals, a methanol:acetic acid:water
(25:4:21) extract was also prepared. About 0.5 g of seeds was powdered
using a mortar and pestle and extracted with 1.5 mL of methanol:water
(1:1). These mixtures were then ultrasonicated (1 h), macerated for
15 h and ultrasonicated again (1 h). Suspensions obtained were
centrifuged (12000 rpm, 5 min), and the supernatant was collected and
filtrated trough a 0.45 µm size pore membrane. The complete extraction
procedure was performed at room temperature.