Auraptene

Deionized water was used for HPLC-Q-TOF-MS and HPLC-Q-TOF-MS/MS analysis and was purified using a Milli-Q system (Merck Millipore, Billerica, MA, USA). HPLC-grade acetonitrile and formic acid were purchased from Merck (Darmstadt, Germany) and ROE (Newark, New Castle, USA), respectively. Methanol (AR) was purchased from the National Institutes for Food and Drug Control (Beijing, China). The seventeen reference substances (seven flavonol glycosides, three flavonols, two polymethoxyflavonoids, three coumarins, one alkaloid, and one limonin), including synephrine (15), neoeriocitrin (36), poncirin (39), eriocitrin (40), naringin (42), naringenin (43), narirutin (44), neohesperidin (51), hesperidin (56), apigenin (59), hesperitin (61), xanthotoxol (71), scopoletin (76), auraptene (80), limonin (79), nobiletin (85), and tangeretin (87) were purchased from Shanghai Yuanye Bio-Technology Co., Ltd. (Shanghai, China).

Eleven samples of Aurantii fructus (AF) samples from different habitats were collected and identified by Associate Professor Tang Qi. Reference standards included synephrine, eriocitrin, neoeriocitrin, rutin, narirutin, naringin, hesperidin, neohesperidin, limonin, xanthotol, poncirin, naringenin, hesperetin, nobiletin, tangeretin and auraptene with a purity of over 98% were purchased from Yuan-ye Bio-Technology Co., Ltd. (Shanghai, China). Chromatographic grade formic acid, methanol, ethanol and acetonitrile were purchased from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China) and used for extractive and analytical procedures.