Flavonoids of willow herb (Chamerion angustifolium (L.) Holub) and their radical scavenging activity during vegetation

PurposeWillow herb has been traditionally used in folk medicine and currently it is a potential raw material for production of phytopharmaceuticals. The aim of this work was to determine the highest amount of flavonoids and the highest radical scavenging activity of willow herb, which was collected in different vegetation phases (intensive growing, bud, massive blooming, ripening of fruits (seeds) and the end of vegetation) and in different parts of the plant (blooms, leaves and stems).Material/methodsRaw material was collected at Kaunas Botanical garden of Vytautas Magnus University. Willow herb was extracted using methanol/water mixture (75/25 v/v, %). Methanolic extracts were purified using solid-phase extraction. For determination of the radical scavenging activity of compounds the HPLC system with the on-line post-column DPPH (1,1-diphenyl-2-picrylhydrazyl) radical reaction detection was used.ResultsFive flavonoids were identified and their quantitative distribution and radical scavenging activity were evaluated. The highest total amount of flavonoids and radical scavenging activity were determined in willow herb collected during the massive blooming phase (11.12 ± 0.34 mg/g and 8.71 ± 0.29 mg/g, respectively).ConclusionsThe highest amount of flavonoids and radical scavenging activity was determined for raw material collected during the massive blooming phase. Evaluation of different parts of the plant during the massive blooming phase revealed that the highest amount of flavonoids and radical scavenging activity are characteristic for blooms of the plant.