LC Quantification of RT-B: The Active Metabolite of a New Resveratrol Derivative RT-A in Rat Plasma

RT-A, a new prodrug based on resveratrol, is currently under investigation. Preclinical studies in rats indicate that RT-A is readily absorbed and rapidly split into an active metabolite RT-B by lysase of the ester bond. An LC method was developed for the determination of RT-B in rat plasma. The assay was performed on a 5 μm Elite C₁₈ column (200 mm × 4.6 mm) with a mobile phase consisting of acetonitrile–0.1% phosphoric acid (28:72, v/v, pH 1.8) at a flow rate of 1.0 mL min^?1. Detection was at 318 nm, and baicalin was used as an internal standard. Calibration was linear over the range of 0.04–10 μg mL^?1 with a correlation coefficient of 0.9994. The mean extraction recoveries of RT-B determined over the concentrations of 0.1, 1.0, and 5.0 μg mL^?1 were (86.5 ± 6.8) %, (82.6 ± 2.0) %, and (92.7 ± 7.9) %. The RSD of intra- and inter-day precisions were all less than 10%. This method was successfully applied to evaluate the pharmacokinetics of RT-B after intravenous administration of RT-A.