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

•UPLC-ESI-Q-TOF/MS method was applied to profile major constituents in Coptis rootlet, HPLC used to compare the content of major alkaloids in Coptis rootlet and Coptis rhizome, this study provides a new model for the composition analysis of Coptis rootlet.•The antibacterial effect of Coptis rootlet against S. aureus was investigated, which provided a new direction for Coptis rootlet future product development.•The effective substances of Coptis rootlet against Staphylococcus aureus were studied for the first time, which provided a reference for future research on new antibacterial drugs.