Inhibition of xanthine oxidase (XO) activity is an effective therapeutic approach for the treatment of diseases such as goutand hyperuricemia. Additionally, the use of XO inhibitors can further be extended to injury treatments such as ischemicreperfusion in various organs such as heart, liver and kidney. In this study, 7 aurone compounds were synthesized andtested on XO and compared with the positive control allopurinol. Compound 5e was identified as the most potent compoundand was able to inhibit half of XO activity at 33.23 μM followed by compounds 5f and 5d at 210.22 μM and 302.0 μM,respectively. Finally, molecular docking study was conducted to understand the important binding interactions of theselected aurone with the active site of XO.

Objective: To evaluate the immunosuppressive effect on human phagocytes and antibacterial activity of dihydromorin and norartocarpetin isolated from Artocarpus heterophyllus heartwoods. Methods: Dihydromorin and norartocarpetin were isolated from Artocarpus heterophyllus heartwoods. A modified Boyden chamber was used to determine the chemotactic activity of human phagocyte. The respiratory burst was evaluated by chemiluminescence assay. Myeloperoxidase (MPO) activity was quantified using a colorimetric assay. The broth microdilution method was performed to assess their antibacterial activity. Results: Dihydromorin exhibited potent inhibitory effect on the chemotactic activity of polymorphonuclear neutrophils (PMNs) with an IC50 value of 5.03 μg/mL. Dihydromorin also inhibited reactive oxygen species production of whole blood cells, PMNs, and monocytes with IC50 values of 7.88, 7.59 and 7.24 μg/mL, respectively. Interestingly, dihydromorin also strongly inhibited the MPO activity of PMNs with an IC50 value of 5.24 μg/mL, which was lower than indomethacin (24.6 μg/mL). Molecular docking of dihydromorin and crystal structure of MPO showed that dihydromorin had close interaction with key amino acid residues such as Arg239 and Gln91. Antibacterial activity assay showed that only dihydromorin had a strong effect against Streptococcus pyogenes with MIC and MBC values of 15.62 and 31.25 μg/mL, respectively. Conclusions: The results suggest that dihydromorin could be developed as an anti-inflammatory and antibacterial agent.