Profiling and identification of chemical components of Shenshao Tablet and its absorbed components in rats by comprehensive HPLC/DAD/ESI-MSⁿ analysis

Shenshao Tablet (SST), prepared from Paeoniae Radix Alba (PRA) and total ginsenoside of Ginseng Stems and Leaves (GSL), is a traditional Chinese medicine (TCM) preparation prescribed to treat coronary heart disease. However, its chemical composition and the components that can migrate into blood potentially exerting the therapeutic effects have rarely been elucidated. We developed an HPLC/DAD/ESI-MSⁿ approach aiming to comprehensively profile and identify both the chemical components of SST and its absorbed ingredients (and metabolites) in rat plasma and urine. Chromatographic separation was performed on an Agilent Eclipse XDB C₁₈ column using acetonitrile/0.1% formic acid as the mobile phase. MS detection was conducted in both negative and positive ESI modes to yield more structure information. Comparison with reference compounds (t_R, MSⁿ), interpretation of the fragmentation pathways, and searching of in-house database, were utilized for more reliable structure elucidation. A total of 82 components, including 21 monoterpene glycosides, four galloyl glucoses, two phenols from PRA, and 55 ginsenosides from GSL, were identified or tentatively characterized from the 70% ethanolic extract of SST. Amongst them, seven and 24 prototype compounds could be detectable in the plasma and urine samples, respectively, after oral administration of an SST extract (4 g·kg^-1) in rats. No metabolites were observed in the rat samples. The findings of this work first unveiled the chemical complexity of SST and its absorbed components, which would be beneficial to understanding the therapeutic basis and quality control of SST.