Synthesis and anti-inflammatory activity of ursolic acid derivative-chalcone conjugates

A series of novel conjugates with ursolic acid core and different chalcone ligands were synthesized via ursolic acid, 4-hydroxyacetophenone and aromatic aldehydes. All of the conjugates were confirmed by the application of IR, ¹H NMR, ¹³C NMR and HR-MS. The anti-inflammatory effect was observed for the target compounds in xylene-induced mouse ear edema and carrageenan-induced paw edema in rats. The preliminary bioassay test demonstrated that these compounds had potent anti-inflammatory activities, and their activities were better than that of the parent ursolic acid. Among them, 1-en-3-oxoursolic acid-chalcone conjugates (6a-6g) exhibited higher activities than analogues 5a-5g and 7a-7g.