Design and synthesis of novel bis-hydroxychalcones with consideration of their biological activities

Abstract

In the present study, eight new substituted bis-hydroxychalcones for the first time were designed, synthesized, purified and fully characterized. Then their inhibitory effects on the diphenolase activity of mushroom tyrosinase were evaluated. The concentration of compounds to scavenge 50% of ABTS (IC50) values were calculated for all the synthesized compounds. IC50 values for 2,2-azinobis (3-ethylbenzothiazoline-sulfonate) assay (ABTS) were in the range of 0.130–0.39 mM. Synthesized compounds possessed an inhibitory effect on tyrosinase activity, too. All of the products were much more active than E and C vitamins. The high antioxidant activity of products could be due to the longer conjugated system which can stabilize the free radical by resonance through a longer system. The concentration of compounds to scavenge 50% of LDOPA (IC50) values were in the range of 0.2–0.6 mM for the tyrosinase inhibition screening Products 4a, 4c, 4d, 4e and 4g which have inhibitory properties comparable to kojic acid (KA). Molecular modeling studies have been performed to achieve insight into the binding mode of the synthesized compounds to the tyrosinase enzyme active site.