Table 2.
Identification of urinary metabolic biomarkers related to exposure to low concentrations of benzene.
| Metabolites | M | VIP a Score | p b Values | Chemical Category |
|---|---|---|---|---|
| Phenylalanylhydroxyproline | 279.13 | 2.42 | 0.0000 | Peptide |
| Tetrahydropteroyltri-L glutamic acid | 703.25 | 2.29 | 0.0001 | Tetrahydrofolic acid |
| Trp Gln Asp Cys Glu | 679.22 | 2.22 | 0.0000 | Peptide |
| Testosterone glucuronide | 465.24 | 2.19 | 0.0000 | Steroid glucuronide |
| 7alpha-Hydroxy-3-oxo-5beta-cholan-24-oic acid | 390.27 | 2.18 | 0.0000 | Bile acid |
| Phosphatidylcholine(44:6) | 889.65 | 2.15 | 0.0000 | Phosphatidylcholine |
| Asp Asp Phe Hys | 532.19 | 2.14 | 0.0000 | Peptide |
| Phosphatidylcholine(42:6) | 861.62 | 2.11 | 00000 | Glycerophospholipid |
| Phosphatidylcholine(42:2) | 869.68 | 2.10 | 0.0000 | Glycerophospholipid |
| Phosphatidylcholine(22:2) | 825.66 | 2.10 | 0.0000 | Glycerophospholipid |
| Folic acid | 441.13 | 2.10 | 0.0000 | Pterins |
| Phosphatidylethanolamine PGE2/22:2(13Z,16Z) | 867.56 | 2.10 | 0.0000 | Glycerophospholipids |
| Phosphatidylcholine(40:3) | 891.64 | 2.10 | 0.0000 | Phosphatidylcholine |
| Cys Hys Ser Trp | 531.19 | 2.10 | 0.0000 | Peptide |
| 1,21-Henicosanediol | 328.33 | 2.09 | 0.0000 | Long chain fatty alcohol |
| Heptadecanoic carnitine | 413.35 | 2.08 | 0.0000 | Acyl carnitine |
| Phosphatidylglycerol (36:1) | 776.55 | 2.06 | 0.0000 | Phosphatidylglycerol |
| Phophatidylethanolamine(44:9) | 841.56 | 2.06 | 0.0000 | Phosphatidylethanolamine |
| 1-(9Z-heptadecenoyl)-2-(7Z, 10Z, 13Z, 16Z-docosatetraenoyl) -glycero-3-phosphoserine |
823.53 | 2.06 | 0.0000 | Glycerophospholipids |
| 1-Methylinosine | 283.28 | 2.05 | 0.0001 | Purine nucleoside |
| Cys Met Thr Tyr | 517.85 | 2.05 | 0.0000 | Peptide |
| Tetradecenoylcarnitine | 369.28 | 2.05 | 0.0000 | Acyl carnitine |
| Phosphatidylethanolamine(22:5) | 778.09 | 2.05 | 0.0000 | Glycerophospholipids |
| Phosphatidylcholine(36:0) | 775.64 | 2.05 | 0.0000 | Glycerophospholipids |
| Coprocholic acid | 450.33 | 2.04 | 0.0000 | Bile acid |
| Asp Leu | 494.24 | 2.04 | 0.0000 | Peptide |
| Phosphatidylserine(38:1) | 817.58 | 2.04 | 0.0000 | Phosphatidylserine |
| Phosphatidic acid(40:1) | 758.58 | 2.03 | 0.0000 | 1,2-diacylglycerol-3-phosphate |
| Phosphatidic acid PA(18:1(12Z)-2OH(9,10)/i-15:0) | 692.46 | 2.03 | 0.0000 | Glycerophospholipids |
| Phosphatidylcholine(32:1) | 731.54 | 2.02 | 0.0000 | Glycerophospholipids |
| Phosphatidylcholine(34:1) | 759.57 | 2.02 | 0.0000 | Glycerophospholipids |
| Phosphatidylethanolamine(34:2) | 715.51 | 2.02 | 0.0000 | Phosphatidylethanolamine |
| Cys Arg Trp Trp | 649.27 | 2.01 | 0.0000 | Peptide |
| Sphingomyelin (D18: 0/14: 1 (9Z) (OH)) |
688.51 | 2.01 | 0.0000 | Sphingolipid |
| Sphingomyelin (d18:1/16:0) | 702.56 | 2.01 | 0.0000 | Sphingolipid |
| Phosphatidylcholine(38:4) | 795.61 | 2.01 | 0.0000 | Glycerophosphocholine |
| Phosphatidylethanolamine(35:0) | 733.56 | 2.01 | 0.0000 | Glycerophospholipids |
| Phosphatidylethanolamine(32:3) | 671.48 | 2.00 | 0.0000 | Glycerophosphoethanolamine |
Note: M: average molecular weight. a: VIP score was obtained from the PLS-DA model. b: p-values were calculated from nonparametric Mann—Whitney test between occupational and environmental exposure groups. Thirty-eight significantly changed (VIP > 2, p value < 0.05 and FDR < 0.01) endogenous metabolites related to benzene exposure are listed in this table.