Flavonoids and stilbenoids with COX-1 and COX-2 inhibitory activity from Dracaena loureiri

Fom the stem wood of Dracaena loureiri, a new homoisoflavanone named loureiriol (1) and eight known flavonoid and stilbenoid derivatives, including 5,7-dihydroxy-3-(4-hydroxybenzyl)-4-chromanone (2), 4,4'-dihydroxy-2,6-dimethoxydihydrochalcone (3), 2,4'-dihydroxy-4,6-dimethoxydihydrochalcone (4), 4'-hydroxy-2,4,6-trimethoxydihydrochalcone (5), 4,6,4'-trihydroxy-2-methoxydihydrochalcone (6), 4,3',5'-trihydroxystilbene (7), 4,3'-dihydroxy-5'-methoxystilbene (8) and 4-hydroxy-3',5'-dimethoxystilbene (9) were isolated. These compounds were evaluated for their inhibitory activity against the enzymes cyclooxygenase-1 and cyclooxygenase-2. Potent but non-selective activity was found for the stilbenoids 7-9 (IC50 1.29-4.92 muM) whereas weak or no activity was observed for the flavonoids 1-6.