Flavonoid alkaloids from Scutellaria moniliorrhiza with anti-inflammatory activities and inhibitory activities against aldose reductase

Four undescribed flavonoid alkaloids, as two pairs of enantiomers, were separated and prepared from the whole plant of Scutellaria moniliorrhiza. In vitro, all four compounds showed anti-inflammatory activities and inhibitory activities against aldose reductase, with IC50 values against the release of β-glucuronidase from polymorphonuclear leukocytes of rats and aldose reductase being in the range 5.16-5.85 μΜ and 2.29-3.03 μΜ, respectively.203