Synthesis and in vitro Anti-proliferative Activities on LNCaP, LS180 and MKN45 of Novel 20(R)-Panaxadiol Derivatives

Background: 20(R)-PD, a tetracyclic triterpenoid, is a non-natural saponin present in the form of protopanaxadiol. Because of its essential biological activities, especially anti-tumor activity, structural modification of 20(R)-PD and the development of innovative and novel 20(R)-PD derivatives with better anti-tumor activity are increasingly relevant. Aims: 20(R)-Panaxadiol (20(R)-PD) can inhibit tumor proliferation. Three series of novel 20(R-PD derivatives were synthesized by modifying the A-ring. Objective: The objective of this work was to synthesize and evaluate the in vitro anti-proliferative activities of 20(R)- PD derivatives in LNCaP, LS180, and MKN45 cancer cells. Structural modifications were performed at the C-3 position and A-ring. Methods: The in vitro anti-proliferative activities of novel derivatives in LNCaP, LS180, and MKN45 cells were evaluated by the MTT assay. The effects of compounds 5 and C9 on apoptosis were determined by flow cytometry. Results: Compounds 5, B2, C2, C4, C7, C8, C9, C10, and C11 exhibited good anti-proliferative activities in LNCaP, LS180, and MKN45 cells in vitro. The best anti-proliferative activity was observed for the C-series derivatives with the introduction of amino acids at the C-3 position. C9 exhibited good potent activity with an IC50 of 2.89 μM. Conclusion: Compound C9 is a potential candidate with potent anti-proliferative activity.