Analysis of phenolic compounds in flowers from wild medicinal plants from northeastern Portugal

This study aimed to analyse phenolic compounds in wild medicinal flowers of Crataegus monogyna, Cytisus multiflorus, Malva sylvestris and Sambucus nigra, by HPLC-DAD-ESI/MS. Flavonols and flavones were the main groups in almost all the studied samples. C. multiflorus sample gave the highest levels of flavonoids, being a chrysin derivative the most abundant flavone. C. monogyna revealed the highest concentration in phenolic acids that were not found in C. multiflorus; 5-O-caffeoylquinic acid was the most abundant phenolic acid found in the first species, being a procyanidin trimer also found. Kaempferol-3-O-rutinoside and quercetin-3-O-rutinoside were the main flavonols present in M. sylvestris and S. nigra, respectively. The studied flowers could be selected for processing extracts with health-promoting properties or to be incorporated into functional beverages or products with bioactive properties related to oxidative stress.