Selectivity dioxygenase inhibitors

Triketones with Heterocyclic Substituents. Triketones represent a well-studied, but still developing, family of herbicides. Some with pyiidyl substituents are among the most active. Much of the research in this area has been reviewed. The triketones are inhibitors of the plant enzyme 4-hydroxyphenylpymvate dioxygenase (HPPD), which plays a key role in the biosynthesis of plastoquinone and tocopherol. Compound 11.6, which is known as nicotinoyl syncarpic acid, is shown as a typical structure of this type. Its potent herbiddal activity led to synthetic work that has yielded many related stmctures in an effort to improve selectivity in the herbicidal action. 

Camper, D. L., Pemich, D. J., Walsh, T. A., Foster, M., Pflugrath, J., Yang, C. Structural Basis For Herbicidal Inhibitor Selectivity Revealed by Comparison of Crystal Structures Of Plant And Mammalian 4-Hydro xyphenylpyruvate Dioxygenases , Biochemistry, (2004), 43(32), 10414-10423. 

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