2.3.1. HPLC-DAD

For the analysis of the extracts, a High Performance Liquid Chromatography system equipped with a quaternary pump with degasser PU-2089 was used, with an AS-950 autosampler and coupled to a diode array spectrophotometric detector MD-2010 (all modules were Jasco International Co., Tokyo, Japan). Data were acquired and processed using the ChromNav software. The working conditions were as follows: acquisition of the spectra in the range 200–650 nm with a resolution of 1 nm; chromatographic separation conducted at room temperature (25 ◦C) on an analytical column TC-C18 (2) (4.6 × 150 mm, particle size 5 μm, Agilent) with a guard column TC-C18 (2) (4.6 × 12.5 mm, particle size 5 μm, Agilent), flow rate 1 mL/min. The injection volume was 20 μL. The two eluent solutions were: A: trifluoroacetic acid (TFA 0.1% *v*/*v*) in bi-distilled water; B: TFA (0.1% *v*/*v*) in acetonitrile (ACN, HPLC grade). The elution program started at 15% B, held for 5 min, then a linear gradient to 50% B was applied in 25 min; re-equilibration time took 15 min.
