The effect of novel pectolinarigenin derivatives bearing a dialkylaminoalkyl substituent at O-7 on cell proliferation was evaluated in vitro in a panel of seven human cancer cell lines including renal adenocarcinoma ACHN, amelanotic melanoma C32, colorectal adenocarcinoma Caco-2, lung large cell carcinoma COR-L23, malignant melanoma A375, lung carcinoma A549 and hepatocellular carcinoma Huh-7D12 cell lines. Pectolinarigenin (2), obtained by hydrolysis of rutinose unit of the pectolinarin (1) isolated from Linaria reflexa, exhibited cytotoxic activity against Caco-2, A549 and A375 cell lines with IC(50) values of 5.3-8.2 microM. The most active pectolinarigenin derivative was 3 characterized by a dimethylamino-propoxy group in O-7 with IC(50) values of 7.2 and 7.4 microM against COR-L23 and A549 cell lines, respectively. A structure-activity relationship analysis of synthesized compounds was performed. None of the tested compounds affected the proliferation of skin fibroblasts 142BR suggesting a selective activity against tumor cells.