Antiproliferative effect of isopentenylated coumarins on several cancer cell lines

33 coumarins, mainly the simple isopentenylated coumarins and derived pyran o- and furanocoumarins, were examined for their antiproliferative activity towards several cancer and normal human cell lines. The pyrano- and furanoc oumarins showed strong activity against the cancer cell lines, whereas they had weak antiproliferative activity against the normal human cell lines. T he decreasing rank order of potency was osthenone (10), clausarin (25), cla usenidin (26), dentatin (24), nordentatin (23), imperatorin (29), seselin ( 27), xanthyletin (21), suberosin (17), phebalosin (8) and osthol (12). The structure-activity relationship established from the results revealed that the 1,1-dimethylallyl and isopentenyl groups have an important role for ant iproliferative activity.