Abstract
The flavone C-glucoside, vicenin-2, in semi-purified extracts of the leaves of Lychnophora ericoides was quantified in rat plasma samples using a method based on reversed-phase high performance liquid chromatography coupled to tandem mass spectrometry. Vicenin-2 was analyzed on a LiChrospher® RP18 column using an isocratic mobile phase consisting of a mixture of methanol: water (30:70, v/v) plus 2.0% glacial acetic acid at a flow rate of 0.8 mL min−1. Genistein was used as internal standard. The mass spectrometer was operated in positive ionization mode and analytes were quantified by multiple reaction monitoring at m/z 595 > 457 for vicenin-2 and m/z 271 > 153 for internal standard. Prior to the analysis, each rat plasma sample was acidified with 200 μL of 50 mmol L−1 acetic acid solution and extracted by solid-phase extraction using a C18 cartridge. The absolute recoveries were reproducible and the coefficients of variation values were lower than 5.2%. The method was linear over the 12.5 – 1500 ng mL−1 concentration range and the quantification limit was 12.5 ng mL−1. Within-day and between-day assay precision and accuracy were studied at three concentration levels (40, 400 and 800 ng mL−1) and were lower than 15%. The developed and validated method seems to be suitable for analysis of vicenin-2 in plasma samples obtained from rats that receive a single i.p. dose of 200 mg kg-1 vicenin-2 extract.