RESUMO
In this study, we used Ultra Performance Liquid Chromatography-Time-of-Flight Mass Spectrometry(UPLC-TOF-MS)to identify the chemical constituents in both ethanol and water extract of Polygonum capitatum. A Waters ACQUITY UPLC BEH C₁₈ column(2.1 mm×100 mm,1.7 μm) was used for separation. The mobile phase was consisted of(A) 0.10% formic acid in water and(B)0.10% formic acid in acetonitrile, and the flow rate was 0.35 mL•min⁻¹. ESI source in negative ion mode was used for MS detection. Structural identification was carried out according to the accurate mass and matching with database. The results showed that flavonoids, polyphenols and lignans were the main components in both extracts. However, the chemical compositions of both extracts were different, e.g. there are less hydrolyzable tannins, loss of ellagic acid and more anthocyanins in ethanol extract. In a conclusion, this study provides an important scientific basis for identifying the active ingredients in P. capitatum, which also help to reveal the pharmacological effect of P. capitatum.