A novel HPTLC-densitometry method was developed for separation and quantitative determination of four flavonoids: quercetin 3-O-β-d-glucuropyranoside (miquelianin; QG), quercetin 3-O-β-d-glucopyranoside (isoquercitrin; IQ), quercetin 3-O-β-d-galactopyranoside (hyperoside; HYP) and quercetin