To clarify the antibacterial material basis of Polygonum capitatum.

D101 macroporous resin and MCI column chromatographic methods were used for the preparation of various fractions,while UHPLC-UV methods were used to establish the chromatogram for the fractions, and the chromatographic peaks were identified by comparing their retention times and UV spectra with the authentic standards; uniform design was adopted for the preparation of samples with different peak concentrations,and their antibacterial effects were evaluated by determining their MIC against Escherichia coli,the bacterium generally found in urinary tract infections. Grey relational analysis was employed to investigate the relationship between the 1 / MIC values and the peak areas and to reveal the antibacterial material basis of Polygonum capitatum.

Peaks 1( gallic acid),6( epicatechin),8( catechin),13( rutin),17( quercetin-3-O-( 2″-O-galloyl)-β-D-glucopyranoside) and 18( quercetin) showed a better correlation( grey relational grades were higher than 0. 8) to the antibacterial activity.

The antibacterial activity of Polygonum capitatum is attributed to the holistic effects of most of the constitutional compounds,and gallic acid,epicatechin,catechin,rutin,quercetin-3-O-( 2″-O-galloyl)-β-D-glucopyranoside and quercetin are the main antibacterial material basis of Polygonum capitatum. This study forms a strong basis for the quality control and exploitation of Polygonum capitatum and its products.