Polyphenol Diversity and Antioxidant Activity of European L. (Cistaceae) Compared to Six Further, Partly Sympatric Species.

This investigation focused on the qualitative and quantitative composition of polyphenolic compounds of Mediterranean northern shore and six further, partly sympatric species (, , , , ). Aqueous extracts of 1153 individual plants from 13 countries were analyzed via high performance liquid chromatography (HPLC). The extracts of were primarily composed of two ellagitannins (punicalagin and punicalagin gallate) and nine flavonol glycosides (myricetin and quercetin glycosides, with m-3--rhamnoside as the dominant main compound). Differences in the proportions of punicalagin derivatives and flavonol glycosides allowed the classification into two chemovariants. Plants containing punicalagin derivatives and flavonol glycosides were especially abundant in the western and central Mediterranean areas and in Cyprus. From Albania eastwards, punicalagin and punicalagin gallate were of much lesser importance and the predominant chemovariant there was a nearly pure flavonol type. With its two chemovariants, takes a central position between the flavonol-rich, purple-flowered clade (besides , here represented by and ) and the more ellagitannin-rich, white- or whitish-pink-flowered clade (here represented by , , and ). The median antioxidative capacity of plant material was, with 166 mg Trolox equivalents/g dry wt, about half of the antioxidative capacity of (301 mg te/g dry wt), the species with the highest antioxidative potential.