Simultaneous determination and pharmacokinetic study of P-hydroxybenzaldehyde, 2,3,5,4′-tetrahydroxystilbene-2-O-β-glucoside, emodin-8-O-β-d-glucopyranoside, and emodin in rat plasma by liquid chromatography tandem mass spectrometry after oral administration of Polygonum multiflorum

Abstract

A rapid and specific liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed for the simultaneous analysis of P-hydroxybenzaldehyde, 2,3,5,4′-tetrahydroxystilbene-2-O-β-glucoside, emodin-8-O-β-D-glucopyranoside, and emodin in rat plasma, and it was applied to the pharmacokinetics (PK) studies of the four compounds from the herb Polygonum multiflorum. The analysis was carried out on a Phenomenex Hydro-RP C₁₈ (150 × 2.0 mm, 4 μm) reversed-phase column by gradient elution with a flow rate of 0.4 mL min⁻¹. All of the analytes including internal standards (I.S.) were monitored by selected reaction monitoring with an electrospray ionization source. Linear responses were obtained for P-hydroxybenzaldehyde, 2,3,5,4′-tetrahydroxystilbene-2-O-β-glucoside, emodin-8-O-β-D-glucopyranoside, and emodin ranging from 1 to 1000 ng mL⁻¹. The intra-day and inter-day precisions (RSD) were less than 8.61% and 8.75%, respectively. The extraction recovery ranged from 77.00 ± 5.54 to 91.30 ± 2.96, and the I.S. was 85.82 ± 3.58%. Stability studies showed that the accuracies of P-hydroxybenzaldehyde, 2,3,5,4′-tetrahydroxystilbene-2-O-β-glucoside, emodin-8-O-β-D-glucopyranoside, and emodin ranged from 94.66 ± 3.54 to 106.84 ± 6.91; the matrix effects ranged from 92.14 ± 3.63 to 103.98 ± 8.71. The validated method was successfully used to determine the concentration–time profiles of P-hydroxybenzaldehyde, 2,3,5,4′-tetrahydroxystilbene-2-O-β-glucoside, emodin-8-O-β-D-glucopyranoside, and emodin.