1 Characterization of phenolic compounds in flowers of wild medicinal plants from Northeastern Portugal Lillian Barros 1,2,a , Montserrat Dueñas 2,a , Ana Maria Carvalho 1 , Isabel C.F.R. Ferreira 1,* , Celestino Santos-Buelga 2,* a Both authors contributed equally 1 CIMO/Escola Superior Agrária, Instituto Politécnico de Bragança, Campus de Santa Apolónia, Apartado 1172, 5301-855 Bragança, Portugal. 2 Grupo de Investigación en Polifenoles (GIP-USAL), Facultad de Farmacia, Universidad de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain. Authors to whom correspondence should be addressed (e-mail: iferreira@ipb.pt, telephone +351273303219, fax +351273325405; e-mail: csb@usal.es; telephone +34 923 294537; fax +34 923 294515).