Objective:To establish the fingerprints of 7 effective parts from Polygonum capitatum ethanol extract

and clarify the contribution of the chemical components represented by all peaks at different sites to the antibacterial effect

and then to reveal the material basis for the efficacy of P. capitatum. Method:UPLC-TOF-MS was introduced to analyze fingerprint of different polar part of P. capitatum ethanol extract

and the chemical constituents of all peaks were analyzed

96-well plate method was adopted to measure minimum inhibitory concentration(MIC) of different polar part for Escherichia coli and Pseudomonas aeruginosa.Partial least squares regression analysis was used to establish the spectrum-effect relationship. Result:Positive correlation peaks of different polar part for E. coli and P. aeruginosa were 9 and 13

respectively;its main antibacterial ingredients ranked as No. 1-5

15

19. Conclusion:The main antibacterial active sites of P. capitatum for E. coli and P. aeruginosa are four polar sites(A

B

C and D) with strong polarity

the main active ingredients are 6-galloylglucose

3

6-digalloylglucose

1

3

6-trigalloylglucose and davidiin.