Phenolic constituents of Convolvulus dorycnium L. flowers

The new phenolic metabolites 3-(2-butoxy-3-caffeoyl-1-hydroxycyclobutyl)-3-hydroxypropanoic acid, named as dorycnic acid (1), and 4-O-(4′-carboxymethyl-2′,4′,6′-trihydroxycyclohexyl) vanillic acid (2), were isolated from the flowers of Convolvulus dorycnium L. Their structures were elucidated on the basis of extensive spectroscopic analysis. Compound 1 displayed significant antioxidative activity in the DPPH assay, with an IC50 value of 31.5 μM.