2-[2-nitro-4-(trifluoromethyl)benzoyl] cyclohexane-1,3-dione (also known as NTBC, an abbreviation of its full chemical name) is a drug originally developed as a herbicide, now used to slow the effects of hereditary tyrosinemia type 1. Since its first use for this indication in 1991, it has replaced liver transplantation as the first-line treatment for this rare condition. It is also being studied in the related condition alkaptonuria. It is marketed under the brand name Orfadin.
The mechanism of action of nitisinone involves reversibile inhibition of 4-hydroxyphenylpyruvate oxidase, thus preventing the formation of maleylacetoacetic acid and fumarylacetoacetic acid, which have the potential to be converted to succinyl acetone, a toxin that damages the liver and kidneys.
Nitisinone has been shown to increase skin and eye pigmentation in mice, and has been suggested as a possible treatment for albinism.
Out of the target weeds, NTTBC is not listed in any of the databases as toxic or ecotoxic substance.
In Europe it is going to be classified and labelled as a sentizizer.
http://en.wikipedia.org/wiki/Nitisinone
Onojafe IF, Adams DR, Simeonov DR, Zhang J, Chan CC, Bernardini IM, Sergeev YV, Dolinska MB, Alur RP, Brilliant MH, Gahl WA, Brooks BP. (2011)Nitisinone improves eye and skin pigmentation defec ts in a mouse model of oculocutaneous albinism. J Clin Invest. 2011 Oct;121(10):3914-23. doi: 10.1172/JCI59372, http://www.ncbi.nlm.nih.gov/pubmed/21968110
Kavana M, Moran GR (2003). "Interaction of (4-hydroxyphenyl)pyruvate dioxygenase with the specific inhibitor 2-[2-nitro-4-(trifluoromethyl)benzoyl]-1,3-cyclohexanedione". Biochemistry 42 (34): 10238–45. doi:10.1021/bi034658b
http://www.pesticideinfo.org/Detail_Chemical.jsp?Rec_Id=PC41945