Theoretical study of the mechanism of hydroxyl radical release from tirapazamine’s undergoing enzymatic catalysis

The mechanism of tirapazamine enzymatic catalysis to release hydroxyl radical has been studied by density functional theory (DFT) at the B3LYP3/6-31G(d) and B3LYP/6-311+G(d) levels. The results indicated that there were two parallel reaction channels in the microcosmic processes of the enzymatic catalysis to release hydroxyl radical. The calculated B3LYP activation barriers including solvent effects were very close to the experimental values.