Synthesis and Biological Evaluation of Glycyrrhetic Acid Derivatives as Potential VEGFR2 Inhibitors.

Vascular endothelial growth factor receptor 2 (VEGFR2) has been proven to play a major role in the regulation of tumor angiogenesis. A series of novel glycyrrhetic acid derivatives were synthesized and evaluated for their VEGFR2 inhibitory activity as well as their antiproliferative properties against four cancer cell lines (MCF-7, HeLa, HepG2, and A549). In vitro biological evaluations against these human tumor cell lines indicate that most of the prepared compounds have antiproliferative activities; compound 3 a (3β-hydroxy-30-(4-phenyl-1-piperazinyl)olean-12-ene-11,30-dione) exhibited the best inhibitory activity against MCF-7 cells, with an IC50 value of 1.08 μm. Compound 3 a also showed the most potent inhibitory activity against VEGFR2 tyrosine kinase, with an IC50 value of 0.35 μm. Docking simulations were performed with the aim of discovering the binding mode of compound 3 a, and the results indicate that 3 a could bind at the VEGFR2 active site.