Extraction and purification of PAs from Chinese bayberry
leaves were carried out essentially according to our previous
procedures [21]. In brief, the leaves were dried at 40uC for 12 h
and then ground well into a powder by milling. The finely ground
powder (4 kg) was extracted with 70% aqueous acetone (40 L)
containing 0.1% (w/v) ascorbic acid at room temperature for
12 h. The extraction was performed two times. The acetone
extracts were pooled and rotary-evaporated under vacuum at
40uC to remove acetone. The aqueous phase (,20 L) was
recovered and washed with hexane (2620 L) to remove nonpolar
material, and then the organic solvents were evaporated under
vacuum. Finally, the aqueous phase was lyophilized to dryness to
obtain the bayberry leaf extracts (BLEs, ,400 g).