Taxonomic study of some species of the subfamily Dipsacoideae Eaton (Caprifoliaceae) by phenolic acid profiles

Abstract

Dipsacoideae has always been problematic for taxonomic delimitation of the taxa because of their morphological similarities and diversity amongst the taxa. Phenolic compounds are found in various organs of plants and are important in terms of chemotaxonomy and pharmacognosy. In this study, the phenolic acid compounds of 12 species of Dipsacoideae were analyzed using high-performance liquid chromatography photodiode array detection (HPLC-PDA) and also evaluated their significances as chemotaxonomic markers. The main phenolic acids were found to be caffeic acid, p-coumaric acid, ferulic acid and salicylic acid. The principal components analysis (PCA) bi-plot indicated that ferulic acid, caffeic acid, cinnamic acid, p-coumaric acid and rosmaric acid were principal components in the studied species dispersion. The species were separated from each other in a principal coordinate analysis (PCoA) plot in terms of their phenolic acid profile. Regarding the results, the high amount of caffeic acid and cinnamic acid could be considered a chemotaxonomic marker for genus Pterocephalus Vaill. and Cephalaria Schrad. respectively. The results indicated that Scabiosa koelzii Rech. and S. amoena Jacq. were placed as a distinct group regarding their phenolic acid profile and established the opinion supported by Greuter and Raus. Consequently, phenolic contents could be applied as a significant marker in the chemotaxonomy of Dipsacoideae. Considering it, we suggest the study of interaction among ecological and genetically factors as well as the studied chemical compounds.