Phenolics in the Tussilago farfara leaves
Coltsfoot leaves (Farfarae folium) are used in the European medicine in respiratory tract diseases, for cough, bronchitis and asthmatic disorders, while in the traditional Chinese medicine only flower buds (Farfarae flos) have been recognized as a medicine. A short literature review shows that most data concern the chemical composition of the coltsfoot flowers. During the carried out studies we have isolated and identified (UV, 1H and 13C NMR, analysis of acid and enzymatic hydrolyze products) six known flavonols from the coltsfoot leaves: kaempferol and its 3-O-β-glucopyranoside and 3-O-α-rhamnopyranosyl(1→6)- β-glucopyranoside, along with quercetin derivatives: 3-O-β-arabinopyranoside, 3-O-β- glucopyranoside and 3-O-α-rhamnopyranosyl(1→6)-β-glucopyranoside. Moreover, we have detected the presence of three phenolic acids.