HPLC-ESI-MS/MS analysis of phenolics and <i>in vitro</i> antioxidant activity of <i>Epilobium angustifolium</i> L.

<p>The aerial parts of <i>Epilobium</i> plants are widely used as folk medicine and food around the world. The present study was aimed to investigate the antioxidant activities and active chemical constituents from <i>Epilobium angustifolium</i> L. The results revealed that the EtOAc extract, rich in phenolic compounds and flavonoids (16.81 ± 0.67 g GAE/100 g extract and 4.95 ± 0.21 g QE/100 g extract, respectively), possessed significantly antioxidant activities in reducing power, DPPH radical scavenging activity, ABTS radical scavenging activity and highly in inhibiting lipid peroxidation activity. Simultaneously, active fractions F to H from EtOAc extracts showing potent <i>in vitro</i> antioxidant activities also contained high content of total phenolic and flavonoid. Twenty-eight compounds were identified as phenolic compounds and flavonoids by LC-MS/MS. The results illustrate that the <i>E. angustifolium</i> L., which is rich in phenolics, could be used as a natural resource of antioxidant ingredient.</p>