Recent Progress in Oleanolic Acid: Structural Modification and Biological Activity

Natural products have been proven as the main source of biologically active compounds, which are potentially useful for drug development. As one of the most studied pentacyclic triterpenes, oleanolic acid (OA) exhibits a broad range of biological activities and serves as a good scaffold for the development of novel derivatives that could be vital in drug discovery for various ailments. Till now, many of its derivatives with multiple bioactivities have been prepared through chemical modifi-cation. This review summarizes the recent reports of OA derivatives (2016-present) and their biologi -cal effects and action mechanisms in vitro and in vivo models, and discusses the design of novel and potent derivatives.