Table 2.

Reported Plasma Concentrations of the Tested Tryptophan Metabolites and IDO1 Inhibitors

(Aarsland et al., 2015), (Schwieler et al., 2016), (Wirthgen et al., 2016), (Soliman et al., 2016), (Shi et al., 2016), (Nayak et al., 2015)

Tryptophan Metabolite	Steady State Plasma Levels (μM)	References
Kynurenine	1.57–3.1	Aarsland et al., 2015; Schwieler et al., 2016
Kynurenic Acid	0.046
Quinolinic Acid	0.306
IDO1 Inhibitor	[Cmax] Plasma Levels (μM)	References
1-Methyl-L-Tryptophan	~30 (porcine)	Wirthgen et al., 2016
1-Methyl-D-Tryptophan	~16	Soliman et al., 2016
INCB024360	~2	Shi et al., 2016
NLG919	~40	Nayak et al., 2015
Norharmane	~	no known reference

C_max, Concentration Maximum