| Kinetin | Organic compounds | Organoheterocyclic compounds | Imidazopyrimidines | Purines and purine derivatives | Details |
| Kynuramine | Organic compounds | Organic oxygen compounds | Organooxygen compounds | Carbonyl compounds | Details |
| L-2,3-Dihydrodipicolinate | Organic compounds | Organic acids and derivatives | Carboxylic acids and derivatives | Amino acids, peptides, and analogues | Details |
| L-3-Aminobutyryl-CoA | Organic compounds | Lipids and lipid-like molecules | Fatty Acyls | Fatty acyl thioesters | Details |
| L-Aspartate-semialdehyde | Organic compounds | Organic acids and derivatives | Carboxylic acids and derivatives | Amino acids, peptides, and analogues | Details |
| L-Aspartyl-4-phosphate | Organic compounds | Organic acids and derivatives | Carboxylic acids and derivatives | Amino acids, peptides, and analogues | Details |
| L-Canaline | Organic compounds | Organic acids and derivatives | Carboxylic acids and derivatives | Amino acids, peptides, and analogues | Details |
| Linoleoyl ethanolamide | Organic compounds | Organic nitrogen compounds | Organonitrogen compounds | Amines | Details |
| Maltohexaose | Organic compounds | Organic oxygen compounds | Organooxygen compounds | Carbohydrates and carbohydrate conjugates | Details |
| Maltopentaose | Organic compounds | Organic oxygen compounds | Organooxygen compounds | Carbohydrates and carbohydrate conjugates | Details |
| Mannosyl-(N-acetylglucosaminyl)2-diphosphodolichol | Organic compounds | Lipids and lipid-like molecules | Prenol lipids | Polyprenols | Details |
| Mannosyl-diinositol-phosphorylceramide | Organic compounds | Lipids and lipid-like molecules | Sphingolipids | Phosphosphingolipids | Details |
| Mannosyl-inositol-phosphorylceramide | Organic compounds | Lipids and lipid-like molecules | Sphingolipids | Phosphosphingolipids | Details |
| Methylarsonate | Organic compounds | Organometallic compounds | Organometalloid compounds | Organoarsenic compounds | Details |
| Methylarsonite | Organic compounds | Organometallic compounds | Organometalloid compounds | Organoarsenic compounds | Details |
| Molybdate | Inorganic compounds | Mixed metal/non-metal compounds | Miscellaneous mixed metal/non-metals | Miscellaneous metallic oxoanionic compounds | Details |
| Molybdenum cofactor (sulfide) | Organic compounds | Organoheterocyclic compounds | Pteridines and derivatives | Pterins and derivatives | Details |
| Molybdopterin-AMP | Organic compounds | Nucleosides, nucleotides, and analogues | Molybdopterin dinucleotides | Not Available | Details |
| N-Acetylglucosaminyl-diphosphodolichol | Organic compounds | Lipids and lipid-like molecules | Prenol lipids | Polyprenols | Details |
| N-Carbamoylsarcosine | Organic compounds | Organic acids and derivatives | Carboxylic acids and derivatives | Amino acids, peptides, and analogues | Details |
| N-Succinyl-2-amino-6-ketopimelate | Organic compounds | Organic acids and derivatives | Carboxylic acids and derivatives | Amino acids, peptides, and analogues | Details |
| N-Succinyl-L,L-2,6-diaminopimelate | Organic compounds | Organic acids and derivatives | Carboxylic acids and derivatives | Amino acids, peptides, and analogues | Details |
| N5-Carboxyaminoimidazole ribonucleotide | Organic compounds | Organic oxygen compounds | Organooxygen compounds | Carbohydrates and carbohydrate conjugates | Details |
| Nordihydroguaiaretate | Organic compounds | Lignans, neolignans and related compounds | Dibenzylbutane lignans | Not Available | Details |
| O-Ureidohomoserine | Organic compounds | Organic acids and derivatives | Carboxylic acids and derivatives | Amino acids, peptides, and analogues | Details |
| Palmitic amide | Organic compounds | Lipids and lipid-like molecules | Fatty Acyls | Fatty amides | Details |
| Phenylethylamine | Organic compounds | Benzenoids | Benzene and substituted derivatives | Phenethylamines | Details |
| Phosphoribosyl-AMP | Organic compounds | Nucleosides, nucleotides, and analogues | Purine nucleotides | Purine ribonucleotides | Details |
| PhosphoribosylformiminoAICAR-phosphate | Organic compounds | Benzenoids | Benzene and substituted derivatives | Phenethylamines | Details |
| Phosphoribulosylformimino-AICAR-P | Organic compounds | Nucleosides, nucleotides, and analogues | Imidazole ribonucleosides and ribonucleotides | 1-ribosyl-imidazolecarboxamides | Details |