A flavonol with diverse biological activities; inhibits NADH oxidase (IC50 = 19 nmol/mg of protein in isolated beef heart mitochondria); scavenges DPPH radicals in a cell-free assay; inhibits GST (IC50 = 1.39 µM for the equine liver enzyme); inhibits MRP1 and MRP2 in MDCK-II cells (IC50s = 13.6 and 15 µM, respectively, for the human proteins)