Minor compounds of the high purity salvianolic acid B freeze-dried powder from Salvia miltiorrhiza and antibacterial activity assessment.

The study explored the isolation and characterisation of three compounds of high purity salvianolic acid B freeze-dried powder extracted from Salvia miltiorrhiza Bunge. A new salvianolic acid, salvianolic acid V (2) together with two known compounds (3-4) was identified. The antibacterial activity tests showed that compound 2 combined with clinical antibiotics such as Levofloxacin or Colistin sulphate together exhibited potent effects against MRSA or Acinetobacter baumanii. This report has considerably extended our knowledge about the diversity and bioactivity of caffeic acid derivatives from S. miltiorrhiza.