[Biological activity and structure of antitumor compounds from Plantago media L].

Tyrosine kinase inhibition and tumor growth inhibition activity of verbascoside and homoplantaginin are described. Both molecules proved to be equally significant inhibitors of isolated EGF-R tyrosine kinases, nevertheless their in vitro antiproliferative activity was variable in cellular assays. Their different inhibitory efficacies could be interpreted on the basis of conformational analysis and lipophilicity evaluation.