Chemical profiling of Coptis rootlet and screening of its bioactive compounds in inhibiting Staphylococcus aureus by UPLC-Q-TOF/MS

Coptis chinensis Franch. is a traditional Chinese medical herb, only the rhizome is used in clinical. However, the other discarded parts, such as rootlet, still contain a large amount of active ingredients. In this article, UPLC-ESI-Q-TOF/MS method was used to identify components of Coptis rootlet, the differences in the contents of four major alkaloids in Coptis rootlet and Coptis rhizome were compared using HPLC. Then the antibacterial effect of the ethanolic extracts of Coptis rootlet and Coptis rhizome on Staphylococcus aureus (S. aureus) were investigated. Finally, S. aureus were cultured for a period of time in the environment of minimum inhibitory concentration (MIC) of Coptis rootlet, extracting intracellular substances, screening for effective antibacterial ingredients. By comparison with secondary mass spectrogram of reference substance, a total of 29 components were identified in Coptis rootlet, the contents of berberine, palmatine, coptisine, epiberberine in rootlet and rhizome were determined and compared. 6 alkaloids were found in the cells of S. aureus, which is the main antibacterial compounds of Coptis rootlet. This study proved the utility of the Coptis rootlet, which is beneficial to the more comprehensive utilization of medicinal plant resources.