Xanthine oxidase (XO) is a key molybdoflavoprotein enzyme that functions in catalysing the oxidation of hypoxanthine and
xanthine to uric acid. Excessive uric acid will results in hyperuricaemia which is the crucial cause of gout. In the present study,
a series of thirty-five of chalcone derivatives were evaluated for inhibitory activity against xanthine oxidase in vitro. From the
study, seventeen compounds (47.2%) exhibited XO inhibitory activity at 200 µg/mL which only four compounds (0.1%)
inhibited XO activity at more than 50%. Compound 14, 1,3-bis(4-hydroxyphenyl)prop-2-en-1-one, showed the strongest
activity more than 50% at 20 µg/mL with IC50 values of 15.31 µg/mL as compared to positive control of allopurinol (IC50
=12.86 µg/mL ). The results suggest that compounds 14 can be further investigated to be developed into a XO inhibitor.