Abstract This study deals with the influence of phenolic hydroxyl groups on the antioxidant capacities of licochalcones.(E)-3-[5-(1, 2-Dimethyl-2-propenyl)-4-hydroxy-3-methoxyphenyl]- 1-(4-hydroxyphenyl)-2-propen-1-one (HMP),(E)-3-[5-(1, 2-dimethyl-2-propenyl)-4-hydroxy-3-