The identification and pharmacokinetic studies of metabolites of salvianolic acid B after intravenous administration in rats

Aim: To identify and quantify the major metabolites of salvianolic acid B (SAB) after intravenous injection in rats. Methods: LC-IT/TOF-MS was used to identify the metabolites in rat bile, plasma, and urine; LC-MS/MS was used to quantify the two major metabolites. Results: In rat bile, plasma, and urine, nine metabolites were identified, including methylated metabolites of SAB, lithospermic acid (LSA), the decarboxylation and methylation metabolites of LSA, salvianolic acid S (SAS), and dehydrated-SAS. The t_1/2 of monomethyl-SAB and LSA were both very short, and monomethyl-SAB had a larger AUC than LSA in rats. Conclusion: Nine metabolites were found, the metabolic pathway was described, and the pharmacokinetic profiles of LSA and monomethyl-SAB were studied, thereby clarifying that methylation was the dominant metabolic pathway for SAB in rats.