The presence of methoxyl at the C-7
position tended to reduce the anti-tyrosinase activity, as
indicated by the experimental results: dihydroquercetin-
4'-methyl ether (1) > dihydroquercetin-7,4'-dimethyl ether
(2) and 5,7,3',5'-tetrahydroxyflavanone (3) > blumeatin
(4); quercetin (5) > rhamnetin (6); luteolin (8) > luteolin-7-
methyl ether (9)