Table 2.

Therapeutic options for modulating the kynurenine pathway in neurodegenerative diseases, with some of the candidates developed and tested so far.

Enzyme Inhibitors	Kynurenic Acid Prodrugs or Analogs
3,4-dimethoxy-N-[4-(3-nitrophenyl)thiazol-2-yl]benzenesulfonamide (Ro-61-8048)	l-Kynurenine
2-(3,4-dimethoxybenzenesulfonylamino)-4-(3-nitrophenyl)-5-(piperidin-1-yl)methylthiazole (JM6)	Combination of l-kynurenine and probenecid N-(2-N,N-dimethylaminoethyl)-4-oxo-1H-quinoline-2-carboxamide hydrochloride
nicotinylalanine	7-Chlorokynurenic acid
	4-Chlorokynurenine (AV-101)