Design, synthesis, and biological evaluation of hypoxic-activation prodrug TH-302 derivatives.

This study aims to design and develop novel and efficient anti-hypoxic cell tumor drugs. Using the TH-302 as lead compound, structural modifications are conducted to synthesize a series of novel derivatives to investigate the structural activity relationship (SAR) against ovarian cancer cell line (SKOV3) and glioblastoma cell line (U87MG) in vitro. The structural modifications mainly include four aspects: changes in substituents on N; changes in isomers; changes in nitro group position; changes in substituting halogens in phosphoramide mustard. The results of CCK-8 assay indicate that the steric hindrance and electronic effects of substituents on N have significant impacts on the activity, while changes in nitro group positions have minimal effects on the activity, and Bromo-phosphoramide mustard exhibits better activity than Chloro-phosphoramide mustard. Compounds 15c and 16d exhibit significantly superior antitumor activity compared to TH-302, with IC50 values of 42 μM and 32 μM for SKOV3 cells, and IC50 values of 47 μM and 41 μM for U87MG cells, respectively.