Identification of anti-hyperuricemic components from Coix seed

Coix seed is a nutritious food with the effect of reducing uric acid. Few studies have been performed on the relevant active compounds. In this study, uric-acid-lowering active compounds were isolated and screened from Coix seed, and their structures were identified using NMR and mass spectrometry. The study showed that Coix seed effectively reduced serum uric acid and creatinine levels, suppressed liver xanthine oxidase activity, and improved kidney damage in mice due to hyperuricemia. Two major anti-hyperuricemic compounds were identified, namely, 1-phenyl-1,3,3-propanetriamine (compound 1) and dihydroferulic acid (compound 2), among which compound 1 was a new compound, and compound 2 was separated from Coix seed for the first time. Two compounds showed potent inhibitory activity in vitro against xanthine oxidase, with IC50 values of 230.48 and 373.09 μM, respectively. Furthermore, the molecular docking results indicated that the compounds could inhibit enzyme activity by interacting with residues within the active pocket of xanthine oxidase. This study provided a new alternative for the development of uric acid-lowering medications by identifying an anti-hyperuricemic alkaloid from Coix seed.