Quantitative UPLC-MS/MS analysis of chlorogenic acid derivatives in antioxidant fractionates from dandelion (Taraxacum officinale) root

Summary: While qualitative studies have identified chlorogenic acids in antioxidant extracts, particularly ethyl acetate-derived extracts, of Taraxacum officinale, quantitative analysis of these phenolic compounds remains largely unreported for this species. In this study, bioactivity-guided fractionation of an antioxidant crude ethyl acetate extract (DPPH = 295.481 ± 0.955 mg TE g^-1 extract) from T. officinale root resulted in a number of reverse-phase fractions that demonstrated high antioxidant activity (DPPH = 1058.733-1312.136 mg TE g^-1 extract), stronger than that of the synthetic antioxidant Trolox^®. UPLC-MS/MS screening of these fractions for the presence of selected mono- and di-caffeoylquinic acids revealed large quantities of 1,5-dicaffeoylquinic acid present in several fractions (853.052-907.324 μg mg^-1), respectively. Due to the antioxidant potency and high levels of 1,5-dicaffeoylquinic acid observed in these fractions, it was concluded that specifically this chlorogenic acid derivative is a major contributor to the antioxidant efficacy of dandelion root.