Search

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 μM) than the positive control quercetin (IC50 37.5 ± 0.8 μM).

Two new flavonoid glycosides, takakin 8-O-β-D-glucuronide 6″methyl ester (2), takakin 8-O-β-D-glucuronide 2″-sodium sulfate (3) together with a known flavonoid glycoside, takakin 8-O-β-D-glucuronide were isolated from the root bark of Helicteres angustifolia (Sterculiaceae). The stru- ctures of these compounds were established on the basis of spectrosco- pic and chemical evidence

A new sesquiterpene lactone glucoside, 8-epicrepioside G(1) together with two known compounds, 8-epidesacylcynaropicrin glucoside (2) and ixerin D (3) were isolated from the whole plant of Ixeris chinensis. Their structures were determined on the basis of chemical and spectro- scopic evidence. Compounds (1),(2) and (3) taste of strong bitterness