Yield and level of phenolic compounds in the inflorescence of yellow everlasting Helichrysum arenarium (L.) Moench collected from natural sites
Introduction: The inflorescence of Helichrysum arenarium (L.) Moench shows anti-inflammatory, antioxidant, detoxifying properties and is traditionally used in liver and biliary tract diseases. Because of its difficult and expensive cultivation, the plant raw material is mainly harvested from natural sites. Objective: The research aimed to determine the local variation in yield and content of flavonoids and phenolic acids in the yellow everlasting inflorescence against the background of the layer structure of vegetation as the rate of plant succession. Methods: The plant raw material was collected from 30 plots of 1 m2, established for three separate populations developing on sandy fallows near Zielona Góra (western Poland). For each study area, percentage cover of the moss-lichen and herb layers, the height, cover and yield of H. arenarium as well as the height and cover of other herbaceous plants were determined. Total contents of flavonoids (expressed as quercetin) and phenolic acids (calculated as caffeic acid) were measured spectrophotometrically, according to Polish Pharmacopoeia. Results: Everlastings reached a cover of up to 70% and the maximum air-dry matter yield of 46.42 g/m2. The height, coverage and yield of H. arenarium were correlated with the parameters describing the herb layer. The content of flavonoids ranged from 0.56 to 0.99%, while that of phenolic acids from 0.82 to 1.80% DM. Conclusions: Yellow everlasting is an important species of early fallows on poor sandy soils and these habitats constitute a rich natural source of herbal raw material. Inflorescences harvested from natural sites are distinguished by a high and similar content of polyphenols and usually meet the requirements of Polish Pharmacopoeia.