Oleanolic acid synthetic oligoglycosides: a review on recent progress in biological activities.

The natural product oleanolic acid has been widely used for treating hepatopathy in China, whereas its clinical application was confined by poor solubility in water. Inspired by remarkable bioactivities and physical properties of triterpenoid saponins, synthesis and biological evaluation of oleanolic acid oligoglycosides drew considerable attention. In the past several years, chemical efforts were made toward glycosylated modifications of oleanolic acid at C3-OH and C17-COOH, of the carbons at ring A/C, and of the functional groups of oleanolic acid lactone. To provide useful information for further study and applications of oleanolic acid derivatives, a total of 177 oleanolic acid synthetic oligoglycosides and their bioactivities (e.g., antiosteoporosis, antidiabetes, antibacterial, anticancer and hemolytic effects) were reviewed; structure-activity relationships and promising agents are indicated.