An aqueous containing emodin and emodin glucuronide was produced 3 times with dichloromethane to remove emodin. The extracted aqueous sample was therefore split into two equal parts, one element was incubated with water and then analyzed by the other one and UPLC by hydrolysis with glucuronidase at 37 C for 30 min and then analyzed by UPLC. The natural product libraries huge difference in peak regions of metabolite and emodin obtained from the samples before and after the hydrolysis, which were represented as Peak areaM and Peak areaE, was determined to be the ratio K Peak areaM Peak areaE e T. Therefore, the concentration of metabolite might be calculated using emodin standard curve. The average SD conversion factor was 1. 0054 0. 023 at a wavelength of 254 nm, determined independently at three different concentrations. UPLC and LC MS/MS Analysis of Emodin and its Glucuronides The conditions used to evaluate emodin and its metabolites were as follows: program, Waters Acquity UPLC with Empower software and photodiode array detector, column, BEH C18, 1. 85%A, wavelength, 254 nm for emodin and its glucuronide and testosterone, and injection volume, 10 L. The check linear Metastasis response range was 0. 625 C100 M for emodin. The mass spectrometer boundaries were established as follows: capillary voltage, 4. 5KV, ion supply temperature, 350 H, desolvation temperature, 108 H, nebulizer gas, nitrogen, 40 psi, turbo gas, argon gas, 20 psi. Identification of Emodin and its Glucuronide Metabolite by LC MS/MS and NMR A mixture of reaction products in aqueous solution was extracted with dichloromethane 3 times. The aqueous fraction was loaded onto an ODS column and cleaned using pure water. The mono glucuronide emodin was eluted using a solvent of H2O/MeOH. The structure of mono glucuronide emodin was identified by UPLC ESI Q TOF MS and 1H NMR. The mass spectrometer guidelines were set as follows: capillary voltage, 4. 5KV, ion source temperature, 350 D, desolvation pan HDAC inhibitor temperature, 108 C, nebulizer gas, nitrogen, 40 psi, turbo gas, argon gas, 20 psi. Kinetic Analysis Permeability of emodin was represented by R eff, which was obtained as described previously. Amounts of percentage metabolized values, portions of glucuronidated emodin excreted into the intestinal lumen, and the percentage absorbed and emodin absorbed were determined as described previously. Briefly, Mgut and Mab were expressed as Eqs. 1 and 2: Mab Qt CAin CAout elizabeth T e1T Mgut QtCMout e2T where Q may be the flow rate of perfusion, could be the interval time of sampling, CAin and CAout are the inlet and outlet concentrations of emodin, and CMout may be the concentration of emodin 3 E glucuronide. 1% Metabolized and self-absorbed were determined as: 1% Absorbed in the intestine Mab Mtotal e3T 1% Metabolites excreted in the intestine Mgut Mtotal e4T where Mtotal could be the total amount of compound perfused within the first 30 min period.