Flavonoids as cycline-dependent kinase inhibitors: inhibition of cdc 25 phosphatase activity by flavonoids belonging to the quercetin and kaempferol series.

In an effort to detect potential inhibitors of cdc25 phosphatase, nineteen flavonoids belonging to the quercetin and kaempferol series have been evaluated, using a colorimetric assay of recombinant human cdc25A tyrosine phosphatase as a cell cycle-specific target. Compounds bearing two benzyl or methyl groups in positions 7 and 4' and acetyl on the hydroxy groups of the sugar moiety showed the maximal activity.