Phenolic constituents of six Hypericum species from Türkiye and their chemotaxonomic relevance

Abstract

Hypericum species have been of great interest to mankind for centuries and Türkiye is a global intersection for these species. In the present study, 20 wild populations of six under-exploited species of Turkish Hypericum from four sections (Hypericaceae; H. orientale, H. bupleuroides, H. venustum, H. hirsutum, H. linarioides and H. androsaemum) were analyzed qualitatively and quantitatively for the presence of 16 phenolic compounds by detailed high-performance liquid chromatography (HPLC) analyses for the first time. Except for quercetin, which was not accumulated by H. bupleuroides, H. venustum and H. linarioides, and hyperoside which was only accumulated by H. bupleuroides and H. venustum, all phenolics were detected at different levels depending on species and their populations. In order to differentiate the samples according to their geographical origin and botanical section, as well as to elucidate the function of the phenolics as chemotaxonomic markers in taxonomy of the Hypericum genus, two multivariate approaches namely, hierarchical cluster analysis (HCA) and principal component analysis (PCA) were performed. The results indicate a significant inter and intra species chemovariability, which has little chemosystemic significance for the taxa studied and makes a poor contribution to the chemotaxonomic understanding of the Turkish Hypericum species. The presented data could be possibly beneficial in clarifying evolutionary relationships within the botanical sections of the genus Hypericum and offer interesting proposals for further studies in the chemotaxonomy and pharmacognosy of this genus.