Psoralen

The standard compounds of AC, HA, MA, BAC, BHC, BMA, Rb₁, Rb₂, Rc, Rd, Re, Rf, Rg₁, and psoralen (purity ≥98%, confirmed by LC-MS/MS, respectively) were purchased from Chengdu Must Bio-Technology Co., Ltd. (Chengdu, China). Fuzi and Hongshen were purchased from Hebei Anguo Medicina Material Company (Hebei, China) and authenticated by Professor Tian-xiang Li (Tianjin University of Traditional Chinese Medicine, Tianjin, China). Acetonitrile and methanol of HPLC grade were obtained from Merck (Darmstadt, Germany). Formic acid of HPLC grade was purchased from ROE SCIENTIFIC INC (Newark, USA). Ultrapure water was purified by a Milli-Q water purification system (Millipore, Milford, MA, USA).
The LC-MS/MS system consisted of an Agilent 1200 HPLC system coupled to an Agilent 6430 triple-quadrupole mass spectrometer equipped with ESI source. All the operations and analysis of data were performed by Mass Hunter Workstation Software from Agilent Technologies (version B.04.00).

Tofacitinib (purity >98%) was purchased from Beijing InnoChem Science & Technology Co., Ltd. Psoralen, isoPsoralen, psoralidin, bergapten, 8-methoxyPsoralen and xanthotoxol were purchased from Chengdu Must Bio-technology Co., Ltd.Midazolam (internal standard (IS); purity >98%) was purchased from the Tianjin King York Pharmaceutical Co. Ltd. (Tianjin, China). HLMs was purchased from Wuhan PrimeTox biomedicine technology Co., Ltd. (Wuhan, China). rCYP3A4 was gifted from Beijing Hospital. Acetonitrile and methanol were bought from Merck Co., Ltd. (Darmstadt, Germany). Carboxymethylcellulose sodium salt (CMC-Na) was purchased from Sinopharm Chemical Reagent Co., Ltd. (Shanghai China). Formic acid was bought from Sigma-Aldrich (St. Louis, MO, United States). Ultrapure water was obtained using a Milli-Q water purification system (Millipore, Billerica, MA, United States). RLMs was prepared in our laboratory. All other chemicals and biological substances were of analytical grade or higher.