Solutions of 20, 10, and 2 mg/mL of extracts E1 and E2 were prepared in water and methanol (n = 3), respectively, and were analyzed by reverse-phase HPLC (RP-HPLC), coupled to an ACE-3-C18-AR (200 mm × 4.6 mm, 3 μm particle size) column from Advanced Chromatography Technologies (Aberdeen, UK), a photodiode array detector (PAD), and mass spectrometry (MS) detector with electrospray ionization source (RP-HPLC-PAD-MS(ESI)) as described by Silvan et al. [51]. Samples of 3,4-DHBA, 3,4-DHPE, 4-HPE, 3,4-DHPE-EA-glucoside, 4-HPE-EA-glucoside, 3,4-DHPE caffeoyl glucoside, quercetin, quercetin 3-O-glucoside, quercetin 3-O-rhamnoside, apigenin 7-O-glucuronide, apigenin 6,8-di-C-glucoside, apigenin 7-O-rutinoside, luteolin, luteolin 3′,7-di-O-glucoside, luteolin 7-O-glucoside, luteolin 4′-O-methyl, 7-O-glucoside, eriodictyol 7-O-rutinoside, eriodictyol 7-O-glucoside, EA, EA 2-glucoside, EMA 2-glucoside, trans-3,4-DHCA, trans-4-HCA, trans-3-M,4-HCA, and trans-4,5-DCQA were identified unambiguously by co-elution and comparison with their retention times, order of elution, UV spectra, and the pseudomolecular and fragment ion masses of the corresponding pure reference substances, and quantified according to the calibration curves of each. The 3,4-DHBA, 3,4-DHBA glucoside, and 3,4-DHPE glucosides were identified tentatively using their corresponding retention time, order of elution, UV spectra, pseudomolecular and diagnostic fragment ion masses, and bibliographic data [52,53,54]. Then, 3,4-DHBA glucoside was quantified as equivalents of 3,4-DHBA, and 3,4-DHPE glucosides as equivalents of 3,4-DHPE. Results of quantification were expressed as mean value standard deviation (n = 3) for dry matter (mg/100 g).