Table 4.

Physicochemical properties and oxidation potentials of kynurenine pathway metabolites determined by DPV on GCE in 0.1 M PBS (pH 7.7).

Metabolite	Chemical Formula	Structure	Eox * [V] (pH = 7.7)	Isoelectric Point [37]
Kyn	C10H12N2O3		0.86	6.11
Kyna	C10H7NO3		1.06	2.31
3HKyn	C10H12N2O4		0.42	6.11
3HAA	C7H7NO3		0.36	3.03
AA	C7H7NO2		0.76	3.34
XA	C10H7NO4		0.65	3.25
QA	C7H5NO4		n.d.	2.27

*—estimated in three-electrode cell consisted of GCE (d = 1 mm, working electrode), Pt wire (counter electrode), and Ag/AgCl (reference electrode);concentration of the analyte: 50 µM; the scan potential:100 mV; n.d.—not detected.