Determination of rosmarinic acid and its N‐substituted analog A1 in rat plasma using high‐performance liquid chromatography–tandem mass spectrometry and its application in pharmacokinetics

Abstract

AbstractBackgroundThe aim of this study was to determine the concentration of rosmarinic acid (RA) and its analog (E)‐3‐(3,4‐dihydroxyphenyl)‐2‐(3‐(3,4‐dihydroxyphenyl)acrylamido)propanoic acid (A1) in rat plasma following oral administration. The significance of this study lies in the development of a rapid, sensitive, and alternative method using liquid chromatography‐tandem mass spectrometry for the accurate quantification and identification of RA and A1 in vivo.MethodsLiquid chromatography‐tandem mass spectrometry was employed to analyze RA and A1 in rat plasma. A C18 column (1.9 µm, 2.1 × 100 mm) with a C18 guard column (5 µm, 2.1 × 10 mm) and a triple‐quadrupole mass spectrometer combined with an electrospray ionization source were utilized. Sample pretreatment involved a one‐step protein precipitation using isopropanol:ethyl acetate (20:80, v/v) as the solvent. Pseudoephedrine hydrochloride served as a standard.ResultsThe developed method exhibited a linear relationship within the concentration ranges of 5‐750 ng/ml for both RA and A1. Relative standard deviations in daily courses were less than 15%, and the relative errors recorded were within 15%. This is the first study to concentrate on determining A1 and RA in rat plasma through oral administration.ConclusionsThe liquid chromatography‐tandem mass spectrometry method developed in this study offers a rapid, sensitive, and alternative approach for the accurate quantification and identification of RA and A1 in vivo. The findings serve as a significant foundation for evaluating the clinical applications of the medicine.