Hydroxycinnamates from elecampane (Inula helenium L.) callus culture

Hydroalcoholic extract from Inula helenium callus tissue showed remarkable reducing capacity. An HPLC/DAD analysis revealed the presence of numerous hydroxycinnamic acid derivatives, including chlorogenic acid (5-O-CQA, 0.1 % dry weight) and 3,5-dicaffeoylquinic acid (3,5-DCQA, 0.3 % dry weight), which were among major constituents of the examined extract. Application of a hyphenated chromatographic method—UHPLC/DAD/MSn—allowed identification of sixteen compounds, derivatives of caffeic acid. Apart from the compounds commonly found in Inula sp., the plant material contained eight conjugates of caffeic acid with aldaric acid. The aldarates constituted over 50 % of the hydroxycinnamate fraction in the examined tissue. This is the first report on the occurrence of the caffeoylaldaric acids in Inula sp. and in a plant tissue culture.