Table 1.
The lowest, the highest, and median concentrations of tryptophan and kynurenine catabolites in DBS.
| Metabolite | Acronym | PubChem CID | # samples >LOQ | Median concentration (mg/L of blood) | The lowest concentration (mg/L of blood) | The highest concentration (mg/L of blood) | HMDB entries (mg/L) | References |
|---|---|---|---|---|---|---|---|---|
| Anthranilate | ATA | 5,459,842 | 134 | 0.0189 | 0.0086 | 0.0470 | 0.0041 +/− 0.0014 [adults (>18years)] | Duranton et al., 2012 |
| Indole-3-acetic acid | IAA | 802 | 134 | 0.6739 | 0.2121 | 3.8892 | 0.4992 +/− 0.2996 [adults (>18years)] | Duranton et al., 2012 |
| Indole-3-aldehyde | IAld | 10,256 | 134 | 0.5527 | 0.2138 | 2.5499 | Expected but not quantified | - |
| Indole-3-acetamide | IAM | 397 | 42 | 0.0057 | 0.0010 | 0.0341 | Expected but not quantified | - |
| Indole-3-butyric acid | IBA | 8,617 | 96 | 0.0703 | 0.0170 | 0.4377 | Detected but not quantified | Cai et al., 2012 |
| Indole-3-lactic acid | ILA | 92,904 | 127 | 0.3641 | 0.1262 | 2.7153 | 0.57 (0.10–1.03) [adults (>18years)] | Magos, 1987 |
| Indole-3-propionic acid | IPA | 3,744 | 35 | 0.0072 | 0.0012 | 0.0676 | 0.091 (0.055–0.21) [adults (>18years)] | Danaceau et al., 2003 |
| Kynurenine | KYN | 846 | 134 | 17.0882 | 7.3402 | 30.5551 | 1.23 (1.02–1.47) [neonates (0–30days)] | Herberth et al., 2015 |
| N-Acetyltryptophan | NAT | 700,653 | 108 | 0.0173 | 0.0030 | 0.1382 | Not quantified in blood | - |
| Tryptophan | TRP | 6,305 | 134 | 2.1699 | 0.7715 | 5.7512 | 3.676–11.23 [neonates (0–30days)] | Human Metabolome Database, 2021 |