Simultaneous determination of homoeriodictyol-7-O-beta-D-Glccopyranoside and its metabolite homoeriodictyol in rat tissues and urine by liquid chromatography-mass spectrometry

A liquid chromatographic-mass spectrometric (LC-MS) method was developed and validated for the simultaneous determination of homoeriodictyol-7-O-beta-D-glycoside (HEDT-Glc) and its active metabolite homoeriodictyol (HEDT) in rat tissues and urine. The analytes and internal standard (dihydromyricetin, IS) were detected by using negative atmospheric pressure chemical ionization mass spectrometry in selected ion monitoring (SIM) mode at m/z 464, 301 and 319 for HEDT-Glc, HEDT and IS, respectively. These compounds were eluted on a Luna reverse phase column. The mobile phase was a methanol-water mixture (70:30, v/v) containing 0.1% of formic acid at a flow rate of 0.8 ml/min. The limit of quantification (LOQ) for both HEDT-Glc and HEDT was 10 ng/ml and their limit of detection (LOD) was 1 ng/ml. Calibration curves were linear (r>0.995) over a wide range of the analytes in tissues and urine. The mean extraction recoveries were >or=75.6% for HEDT-Glc and >or=82.4% for HEDT from biological matrixes. Accuracy, expressed as the relative error, ranged from -4.0% to 3.8% for HEDT-Glc and from -2.8% to 4.7% for HEDT. The method was successfully applied to the estimation of HEDT-Glc and its metabolite HEDT in rat tissues and urine.