HPPD

The results show that sulcotrione behaves as time-independent reversible inhibitor. Similar results are previously described for natural β-triketones, and for the synthetic β-triketone NTBC. However it is the first time that such behavior is observed using a purified hydroxyphenylpyruvate dioxygenase (HPPD) and a synthetic β-triketone, namely sulcotrione. Inhibition kinetic analysis, performing with 3 hydroxyphenylpyruvate (HPP) and sulcotrione concentrations, show that the apparent K _M increasing with sulcotrione concentration. This behavior is consistent with the data present in the literature, describing sulcotrione as a competitive inhibitor of HPPD.