Phenolic composition of leaf and flower extracts of black cherry (Prunus serotina Ehrh.)

Abstract

Key Message: The best yields in the extraction of hydroxycinnamic acids, flavanols and total phenolics from black cherry flowers were obtained with 40% ethanol and the poorest with water. A 30% higher content of total phenolics was obtained from leaves by using methanol rather than water. Context: Black cherry (Prunus serotina Erhr.) is widespread in Europe. Because it is an invasive species, most research has been aimed at trying to find a method to remove this shrub from forests. The incentive for the development of the research was that we were trying to find a possible folk use of black cherry leaves and flowers. Aims: The aim of this work was to study the detailed phenolic profile of extracts of P. serotina leaves and flowers. Methods: Three types of extracts of P. serotina were made. The extracts were analysed for differences in phenolics content based on different extraction methods. HPLC-MSn was used to identify the phenolic compounds, and HPLC–DAD was used for their quantification. Results: The results show that different extraction methods result in differences in the amount of extractables. Flavanols are the main group of identified compounds in both leaves and flowers. A larger extraction efficiency leads to a higher amount of phenolics in the flowers compared to leaves (49.8 vs. 36.5 g/kg dry weight). No difference was detected in the amount of phenolics between water extracts of leaves and flowers. Each extract can be considered rich in phenolics. Conclusion: This work shows that leaves and flowers of P. serotina are a rich source of phenolic compounds. We provide interesting results that might be of interest in the industrial valuation of several compounds.