Synthesis and anti-tumor activity of Z-Gly-Pro-OH-podophyllotoxin derivatives

Ten novel podophyllotoxin derivatives (IIIa-IIIi and IV) were synthesized by three-step reactions using podophyllotoxin and N-benzyloxycarbonyl glycine-L-proline as raw material. The structures of the target compounds were confirmed by ¹H NMR, ¹³C NMR and MS. MTT method was used to test anti-tumor activity of the target compounds on HepG2, THP-1, HeLa and MCF-7 cells. The results showed that all the target compounds had inhibitory activity against HepG2, THP-1, HeLa and MCF-7 cells, and the inhibitory activity of IIIa on HepG2 cells was the most prominent with an IC₅₀ value of 0.58 nmol/L. The binding mode of compound IIIa and FAPα was studied by molecular docking. Compound IIIa could bind to multiple sites of FAPα enzyme.