Discovery of 1’-acetoxychavicol acetate (ACA) as a promising antibacterial compound from galangal (Alpinia galanga (Linn.) Willd)

•The main antibacterial compounds in galangal were discovered.•1′-acetoxychavicol acetate (ACA) had good bactericidal effects against S. aureus.•ACA was found to damage the cell membrane integrity of S. aureus.•Proteomic analysis indicated that 2787 differentially expressed proteins were changed by ACA treatment.•Galangal is a promising spice rich in antibacterial compounds, especially ACA.