Glycoside modification of oleanolic acid derivatives as a novel class of anti-osteoclast formation agents Original Research Article

Oleanolic acid, a natural product, possesses an anti-osteoclast formation activity. Targeting at discovery of novel and potent anti-bone resorption agents, 22 glycosides of oleanolic acid derivatives (including d-galactopyranosides, d-glucopyranosides, d-xylopyranoses, d-arabopyranoses and d-glycuronic acids) were synthesized at phase-transfer-catalyzed conditions (K2CO3, Bu4NBr, CH2Cl2–H2O) and their inhibitory activity on the formation of osteoclast-like multinucleated cells (OCLs) induced by 1α, 25-dihydroxy vitamin D3 was evaluated in a co-culture assay system. The structure–activity relationships of these compounds were also discussed.