A New Lipoxygenase Inhibitory Flavonoid from the Kino of Eucalyptus citriodora

摘要

A new lipoxygenase inhibitory flavonoid, 8-[1-(p-hydroxyphenyl)ethyl]rhamnocitrin (1), together with four known compounds, cinnamic acid (2), p-coumaric acid (3), caffeic acid (4), and gallic acid (5), was isolated from the kino of Eucalyptus citriodora, and their structures were elucidated on the basis of spectroscopic methods including 2D NMR spectra. These compounds were tested for inhibitory activity against 15-lipoxygenase. Compound 1 showed stronger inhibitory activity (IC50 27.6 +/- 0.7 M) than the positive control quercetin (IC50 37.5 +/- 0.8 M).