HPLC analyses were performed on the apparatus Agilent 1200 RR HPLC (Agilent, Waldbronn, Germany), equipped with a DAD detector, using reverse-phase analytical column Zorbax SB-C18 (Agilent), as previously described in detail [73 (link)]. Orthophosphoric acid in water (1% v/v) and acetonitrile were mobile phases A and B, respectively. The parameters were as follows. Flow rate: 1 mL/min; gradient elution: 98–90% A (0–5 min); 90% A (5–15 min); 90–85% A (15–20 min); 85–70% A (20–25 min); 70–40% A (25–30 min); 40–0% A (30–34 min); detection—260 and 320 nm. The quantity of investigated compounds in the PEx (PG, PN, and EA) and GA was determined using calibration curves of their standards, and the results were expressed as mg/gram of dry weight. As shown in our previous paper [24 (link)] and the Supplementary Figure S1 of this paper, the main compounds of PEx were PG (67.26 ± 0.81 mg/g), PN (31.91 ± 0.22 mg/g), EA (25.11 ± 0.06 mg/g), and GA (9.75 ± 0.05 mg/g).
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