Phenolic components of arctium lappa L. leaves

The investigation of phenolic compounds of the leaves Arctium lappa was carried out. The leaves of Arctium Lappa was extracted with 70% EtOH. The extract was evaporated up to aqueous solution with the following extraction with CHCl3, EtOAc and n-BuOH. The precipitate from the n-BuOH layer was twice chromatographed on the SG column, using CHCl3-MeOH as eluent in gradient regime and CHCl3-MeOH-H2O 61:32:6 in isocratic regime.

There were isolated rutine and camppherole-3-rutinoside. The evapd n-BuOH layer was chromatographed on the same sorbent using as eluent petrol-EtoAc in gradient regime (up to 80 % EtOAc), EtOAc, EtOAc-MeOH (up to 12 % MeOH). The fraction, containing three phenolic compounds was rechromatographed on the same sorbent using CHCl3-MeOH as eluent in gradient regime (up to 9 % MeOH). There were isolated clorogenic acid methyl ester and 1,5-dicaffeoylqinic acid.

The identification of the compounds was carried out by the 1H-NMR, UV spectral data.

The aqueous layer of the leaves contain the caffeic acid derivatives, which absent in the aqueous layer juice.