Flavonol glycosides from Lysimachia clethroides Chemical constituents of antitumor active fraction of Lysimachia clethroides Chemical constituents of antitumor active fraction of Lysimachia clethroides Simultaneous determination of five flavonoids in extract of Lysimachia clethroides by HPLC Analysis of four flavonoids in Lysimachia clethroides using ionic liquid-assisted extraction