Characterization of phenolic compounds in wild medicinal flowers from Portugal by HPLC-DAD-ESI/MS and evaluation of antifungal properties

In the present work, the phenolic compounds of Castanea sativa, Filipendula ulmaria and Rosa micrantha flowers from Northeastern Portugal were characterized by HPLC-DAD-ESI/MS. Furthermore, it was performed a screening of their antifungal potential against Candida species (Candida albicans, Candida glabrata, Candida parapsilosis and Candida tropicalis). C sativa sample gave the highest amount of phenolic compounds (18973 +/- 40 mu g/g, fw) and hydrolysable tannins (14873 +/- 110 mu g/g). The highest amounts of phenolic acids (569 +/- 20 mu g/g) and flavonoids (6090 +/- 253 mu g/g) were obtained in F. ulmaria and R. micrantha samples, respectively. Hydrolysable tannins (e.g. tri and digalloyl HHDP glucose) were the main group of phenolic compounds in C sativa and F. ulmaria samples, while flavonoids (e.g. (+)-catechin and procyanidin dimers and trimers) were the most abundant group in R. micrantha. Thus, the stronger effect showed by this latter against all the Candida species (MIC <= 0.155 mg/mL) and, particularly its fungicide effects in C glabrata, might be related to the mentioned flavonoids that were inexistence in the other samples. (C) 2012 Elsevier B.V. All rights reserved.