Table 2 List of ESI– metabolites, together with their molecular weights, chromatographic retention times, Kegg and HMDB IDs, and HMDB classification, when available.

1

Malic acid

HMDB0000156

C00149

Hydroxyacid

2

Imidazolelactic acid

HMDB0002320

C05132

Imidazoles

3

Hexanoylglycine

HMDB0000701

N.A

N-acyl-alpha aminoacid

4

Dihydroxy-5-methylthio-4-pentenoic acid (DMTPA)

HMDB0240388

N.A

Fatty acids and conjugated

5

Sulfooxybutanoic acid

HMDB0130137

N.A

Fatty acids

6

Heptanoylglycine

HMDB0013010

N.A

N-acyl-alpha aminoacid

7

N-lactoylvaline

HMDB0062181

N.A

N-acyl-alpha aminoacid

8

Phenylacetylglycine

HMDB0000821

C05598

N-acyl-alpha aminoacid

9

Ethylphenyl sulfate

HMDB0062721

N.A

Arylsulfates

10

3-Hydroxy-3-(4-hydroxy-3-methoxyphenyl) propanoic acid

HMDB0133486

N.A

Phenylpropanoic acids

11

[2-Hydroxy-5-(prop-2-en-1-yl)phenyl]oxidanesulfonic acid

HMDB0135258

N.A

Arylsulfates

12

5-Aminoimidazole-4-carboxamide glutaric acid

N.A

N.A

Imidazole derivative

13

Indolylacryloylglycine

HMDB0006005

N.A

N-acyl-alpha aminoacid

14

2-[4-hydroxy-3-(sulfooxy) phenyl]acetic acid

HMDB0125151

N.A

Arylsulfates

15

Benzoyl glutamic acid

N.A

N.A

Glutamic acid and derivatives

16

Propyl hydroxyhippuric acid

N.A

N.A

N-acyl-alpha aminoacids and derivatives

17

5-(Hydroxyphenyl)-gamma-valerolactone-O-sulphate

HMDB0059993

N.A

Arylsulfates

18

Hydroxybutyric acid glucuronide

N.A

N.A

19

Methylguanosine

HMDB0001563

C04545

Purine nucleosides

20

4-Methylcatechol O-glucuronide

HMDB0240460

N.A

21

Octenedioyl glutamine

N.A

N.A

Glutamic acid and derivatives

22

N-(indol-3-acetyl) glutamine

HMDB0013240

N.A

Glutamic acid and derivatives

23

Succinyl tryptophan

N.A

N.A

Tryptophan derivative (aminoacid)

24

2-Methoxy-4-vinylphenol glucuronide

N.A

N.A

25

Pyr-Xle-Ser

N.A

N.A

Peptides

26

Hydroxy methoxy indole glucuronide

HMDB0010363

C03033

Carbohydrates and carbohydrate conjugates

27

Suberoyl glucuronic acid

N.A

N.A

28

Alpha-CEHC sulfate

N.A

N.A

Vitamin E metabolite

29

Feruloyl-quinic acid

HMDB0030669

C02572

Quinic acids and derivatives

30

(epi)Catechin sulfate

HMDB0012467

N.A

Sulfated flavonoids

31

Dihydro(iso)ferulic acid glucuronide

HMDB0041723

N.A

Phenolic glycosides

32

Dihydro(iso)ferulic acid glucuronide

HMDB0041723

N.A

Phenolic glycosides

33

Dimethylene suberic acid glucoronide

N.A

N.A

Medium chain fatty acids

34

Dimethylene suberic acid glucoronide

N.A

N.A

Medium chain fatty acids

35

Decenedioyl glucuronic acid

N.A

N.A

36

Methylcathecol glucuronide sulfate

N.A

N.A

37

Methyl(epi)catechin sulfate

N.A

N.A

38

Hydroxyandrosterone sulfate isomer

N.A

N.A

C21 steroids

39

Dodecanedioyl glucuronic acid

N.A

N.A

40

Androstenol glucuronide

N.A

N.A

C21 steroids

41

Alpha-CEHC glucuronide

HMDB0062445

N.A

Vitamin E metabolite

42

Uroerythrin (biotrypirrin A)

HMDB0003323

N.A

Pyrroles

43

(epi)Catechin glucuronide

HMDB0240435

N.A

Flavonoids

44

Trihydroxyoctadecenoic acid glucuronide

N.A

N.A

45

Trihydroxyoctadecenoic acid glucuronide

N.A

N.A

46

Trihydroxycholanoic acid glucuronide

N.A

N.A

47

(3a,5b,7a,12a)-24-[(Carboxymethyl)amino]-1,12-dihydroxy-24-oxocholan-3-yl-b-d-Glucopyranosiduronic acid

HMDB0002472

N.A

Oximes