ABSTRACT
Rosmarinic acid,a hydrosoluble polyphenolic hydroxyl compound,is the active ingredient in such traditional Chinese medicines as Menthae Haplocalycis Herba,Salviae Miltiorrhizae Radix et Rhizoma,Rosemary,Perillae Folium. Because of its good anti-inflammatory,anti-oxidant and anti-tumor effects,it is widely used in food,medicine and other fields. However,the metabolic process and metabolites of rosmarinic acid in vivo have not been completely defined. In this study,an efficient method of ultra-high performance liquid chromatography combined with linear ion trap-Orbitrap(UHPLC-LTQ-Orbitrap) mass spectrometer was used to analyze the metabolites in vivo of rosmarinic acid in rats. Plasma,urine and feces samples were collected after oral administration of rosmarinic acid. After biological samples were processed by solid phase extraction,Acquity UPLC BEH C18 column(2. 1 mm × 100 mm,1. 7 μm) was used with 0. 1% formic acid(A)-acetonitrile(B) solution as the mobile phase at the speed of 0. 30 m L·min-1 and temperature of 35 ℃ under gradient conditions. The plasma,urine,feces and the blank samples were then analyzed by ESI-LTQ-Orbitrap under both negative and positive ion modes. Based on the accurate mass measurement(<5),MS/MS fragmentation patterns,standards and literatures,a total of 36 metabolites were screened out and identified in the biological samples collected from rats after intragastric administration. Three were identified 3 from rat plasma,31 from urine,and 7 from feces. The main metabolic pathways of rosmarinic acid in rats can be divided into five parts. Rosmarinic acid were first decomposed into small molecules,such as trans-caffeic acid,coumaric acid,m-hydroxybenzoic acid and Danshensu,which were followed by sulfation,methylation,glucuronic acid conjugation and glucose conjugation. The results showed that UHPLC-LTQ-Orbitrap mass spectrometer could be used to analyze the metabolism of rosmarinic acid in rats,and provide reference for further studies on toxicology,pharmacodynamics and secondary development of Chinese medicine.