| Thymine | Organic compounds | Organoheterocyclic compounds | Diazines | Pyrimidines and pyrimidine derivatives | Details |
| Phosphoenolpyruvic acid | Organic compounds | Organic acids and derivatives | Organic phosphoric acids and derivatives | Phosphate esters | Details |
| Pyroglutamic acid | Organic compounds | Organic acids and derivatives | Carboxylic acids and derivatives | Amino acids, peptides, and analogues | Details |
| Sarcosine | Organic compounds | Organic acids and derivatives | Carboxylic acids and derivatives | Amino acids, peptides, and analogues | Details |
| Phosphoserine | Organic compounds | Organic acids and derivatives | Carboxylic acids and derivatives | Amino acids, peptides, and analogues | Details |
| D-Ribose | Organic compounds | Organic oxygen compounds | Organooxygen compounds | Carbohydrates and carbohydrate conjugates | Details |
| Uridine 5'-monophosphate | Organic compounds | Nucleosides, nucleotides, and analogues | Pyrimidine nucleotides | Pyrimidine ribonucleotides | Details |
| Uric acid | Organic compounds | Organoheterocyclic compounds | Imidazopyrimidines | Purines and purine derivatives | Details |
| Vanillylmandelic acid | Organic compounds | Benzenoids | Phenols | Methoxyphenols | Details |
| Xanthine | Organic compounds | Organoheterocyclic compounds | Imidazopyrimidines | Purines and purine derivatives | Details |
| Urea | Organic compounds | Organic acids and derivatives | Organic carbonic acids and derivatives | Ureas | Details |
| Uridine | Organic compounds | Nucleosides, nucleotides, and analogues | Pyrimidine nucleosides | Not Available | Details |
| Uracil | Organic compounds | Organoheterocyclic compounds | Diazines | Pyrimidines and pyrimidine derivatives | Details |
| Tryptamine | Organic compounds | Organoheterocyclic compounds | Indoles and derivatives | Tryptamines and derivatives | Details |
| Vitamin A | Organic compounds | Lipids and lipid-like molecules | Prenol lipids | Retinoids | Details |
| Tyramine | Organic compounds | Benzenoids | Benzene and substituted derivatives | Phenethylamines | Details |
| 3-Amino-2-piperidone | Organic compounds | Organic acids and derivatives | Carboxylic acids and derivatives | Amino acids, peptides, and analogues | Details |
| 16a-Hydroxyestrone | Organic compounds | Lipids and lipid-like molecules | Steroids and steroid derivatives | Estrane steroids | Details |
| (S)-3,4-Dihydroxybutyric acid | Organic compounds | Organic acids and derivatives | Hydroxy acids and derivatives | Beta hydroxy acids and derivatives | Details |
| 2-Hydroxyestrone | Organic compounds | Lipids and lipid-like molecules | Steroids and steroid derivatives | Estrane steroids | Details |
| Erythrono-1,4-lactone | Organic compounds | Organoheterocyclic compounds | Lactones | Gamma butyrolactones | Details |
| 2-Methyl-3-hydroxybutyric acid | Organic compounds | Lipids and lipid-like molecules | Fatty Acyls | Fatty acids and conjugates | Details |
| 3-Hydroxymethylglutaric acid | Organic compounds | Lipids and lipid-like molecules | Fatty Acyls | Fatty acids and conjugates | Details |
| 3-Hydroxybutyric acid | Organic compounds | Organic acids and derivatives | Hydroxy acids and derivatives | Beta hydroxy acids and derivatives | Details |
| 2-Phosphoglyceric acid | Organic compounds | Organic oxygen compounds | Organooxygen compounds | Carbohydrates and carbohydrate conjugates | Details |
| 17a-Hydroxypregnenolone | Organic compounds | Lipids and lipid-like molecules | Steroids and steroid derivatives | Pregnane steroids | Details |
| 17-Hydroxyprogesterone | Organic compounds | Lipids and lipid-like molecules | Steroids and steroid derivatives | Pregnane steroids | Details |
| 3-(3-Hydroxyphenyl)propanoic acid | Organic compounds | Phenylpropanoids and polyketides | Phenylpropanoic acids | Not Available | Details |
| 2-Methylcitric acid | Organic compounds | Organic acids and derivatives | Carboxylic acids and derivatives | Tricarboxylic acids and derivatives | Details |
| 2-Pyrocatechuic acid | Organic compounds | Benzenoids | Benzene and substituted derivatives | Benzoic acids and derivatives | Details |