Lipoxygenase inhibition by anadanthoflavone, a new flavonoid from the aerial parts of Anadenanthera colubrina

Chemical investigation of the aerial parts of Anadenanthera colubrina led to the isolation of a new flavonoid named anadanthoflavone (1), along with 11 known Compounds: alnusenol, lupenone, lupeol, betulinic acid, alpha-amyrin, beta-amyrin, beta-sitosterol, stigmasterol, apigenin, 4-hydroxybenzoic acid and cinnamic acid. The isolated compounds were evaluated for their inhibitory activity on human platelet 12-lipoxygenase (12-hLO), human reticulocyte 15-lipoxygenase (15-hLO) and soybean lipoxygenase-1 (15-sLO). Compound 1 was found to be active against 12-hLO and 15-hLO with IC50 values of 13 +/- 3 muM and 17 +/- 3 muM, respectively. Apigenin selectively inhibited the activity of 15-hLO (IC50:4.0 +/- 1 muM), while lupenone, lupeol and alpha-amyrin were found active against 15-sLO (IC50: 22 +/- 3,muM, 35 +/- 9 muM and 15 +/- 3 muM, respectively).