The extract was purified by an extraction in solid phase.
The extract (approx. 1 g) was resuspended with 10 mL of acidified water with HCl at 0.15%. The C-18 Sep-Pack cartridge (Agilent Technologies) was activated passing through 10 mL of acidified methanol (0.15% of HCl), followed by 10 mL of acidified water (0.15% of HCl).