List of EC numbers (EC 1)

This list contains a list of EC numbers for the first group, EC 1, oxidoreducatases, placed in numerical order as determined by the Nomenclature Committee of the International Union of Biochemistry and Molecular Biology.

1 EC 1.1 Acting on the CH-OH group of donors
- 1.1 EC 1.1.1 With NAD or NADP as acceptor
- 1.2 EC 1.1.2 With a cytochrome as acceptor
- 1.3 EC 1.1.3 With oxygen as acceptor
- 1.4 EC 1.1.4 With a disulfide as acceptor
- 1.5 EC 1.1.5 With a quinone or similar compound as acceptor
- 1.6 EC 1.1.9 With a copper protein as acceptor
- 1.7 EC 1.1.98 With other, known, acceptors
- 1.8 EC 1.1.99 With other acceptors
2 EC 1.2 Acting on the aldehyde or oxo group of donors
- 2.1 EC 1.2.1 With NAD or NADP as acceptor
- 2.2 EC 1.2.2 With a cytochrome as acceptor
- 2.3 EC 1.2.3 With oxygen as acceptor
- 2.4 EC 1.2.4 With a disulfide as acceptor
- 2.5 EC 1.2.5 With FAD as acceptor
- 2.6 EC 1.2.7 With an iron-sulfur protein as acceptor
- 2.7 EC 1.2.99 With other acceptors
3 EC 1.3 Acting on the CH-CH group of donors
- 3.1 EC 1.3.1 With NAD or NADP as acceptor
- 3.2 EC 1.3.2 With a cytochrome as acceptor
- 3.3 EC 1.3.3 With oxygen as acceptor
- 3.4 EC 1.3.5 With a quinone or related compound as acceptor
- 3.5 EC 1.3.7 With an iron-sulfur protein as acceptor
- 3.6 EC 1.3.8 With an FAD as prosthetic group
- 3.7 EC 1.3.98 With FMN acceptor
- 3.8 EC 1.3.99 With other acceptors
4 EC 1.4 Acting on the CH-NH₂ group of donors
- 4.1 EC 1.4.1 With NAD or NADP as acceptor
- 4.2 EC 1.4.2 With a cytochrome as acceptor
- 4.3 EC 1.4.3 With oxygen as acceptor
- 4.4 EC 1.4.4 With a disulfide as acceptor
- 4.5 EC 1.4.5 With an iron-sulfur flavoprotein as acceptor
- 4.6 EC 1.4.7 With an iron-sulfur protein as acceptor
- 4.7 EC 1.4.9 With TTQ acceptors
- 4.8 EC 1.4.98 With tryptophan tryptophylquinone acceptors
- 4.9 EC 1.4.99 With other acceptors
5 EC 1.5 Acting on the CH-NH group of donors
- 5.1 EC 1.5.1 With NAD or NADP as acceptor
- 5.2 EC 1.5.3 With oxygen as acceptor
- 5.3 EC 1.5.4 With a disulfide as acceptor
- 5.4 EC 1.5.5 With a quinone or similar compound as acceptor
- 5.5 EC 1.5.7 With an iron-sulfur protein as acceptor
- 5.6 EC 1.5.8 With a flavin as acceptor
- 5.7 EC 1.5.99 With other acceptors
6 EC 1.6 Acting on NADH or NADPH
- 6.1 EC 1.6.1 With NAD or NADP as acceptor
- 6.2 EC 1.6.2 With a heme protein as acceptor
- 6.3 EC 1.6.3 With oxygen as acceptor
- 6.4 EC 1.6.4 With a disulfide as acceptor
- 6.5 EC 1.6.5 With a quinone or similar compound as acceptor
- 6.6 EC 1.6.6 With a nitrogenous group as acceptor
- 6.7 EC 1.6.7 With an iron-sulfur protein as acceptor
- 6.8 EC 1.6.8 With a flavin as acceptor
- 6.9 EC 1.6.99 With other acceptors
7 EC 1.7 Acting on other nitrogenous compounds as donors
- 7.1 EC 1.7.1 With NAD⁺ or NADP⁺ as acceptor
- 7.2 EC 1.7.2 With a cytochrome as acceptor
- 7.3 EC 1.7.3 With oxygen as acceptor
- 7.4 EC 1.7.5 With miscellaneous acceptora
- 7.5 EC 1.7.6 With hydrogen as acceptor
- 7.6 EC 1.7.7 With an iron-sulfur protein as acceptor
- 7.7 EC 1.7.99 With other acceptors
8 EC 1.8 Acting on a sulfur group of donors
- 8.1 EC 1.8.1 With NAD or NADP as acceptor
- 8.2 EC 1.8.2 With a cytochrome as acceptor
- 8.3 EC 1.8.3 With oxygen as acceptor
- 8.4 EC 1.8.4 With a disulfide as acceptor
- 8.5 EC 1.8.5 With a quinone or similar compound as acceptor
- 8.6 EC 1.8.6 With a nitrogenous group as acceptor
- 8.7 EC 1.8.7 With an iron-sulfur protein as acceptor
- 8.8 EC 1.8.98 With other, known, acceptors
- 8.9 EC 1.8.99 With other acceptors
9 EC 1.9 Acting on a heme group of donors
- 9.1 EC 1.9.3 With oxygen as acceptor
- 9.2 EC 1.9.6 With a nitrogenous group as acceptor
- 9.3 EC 1.9.99 With other acceptors
10 EC 1.10 Acting on diphenols and related substances as donors
- 10.1 EC 1.10.1 With NAD or NADP as acceptor
- 10.2 EC 1.10.2 With a cytochrome as acceptor
- 10.3 EC 1.10.3 With oxygen as acceptor
- 10.4 EC 1.10.99 With plastocyanin acceptors
- 10.5 EC 1.10.99 With other acceptors
11 EC 1.11 Acting on a peroxide as acceptor
- 11.1 EC 1.11.1 Peroxidases
- 11.2 EC 1.11.2 Peroxygenase
12 EC 1.12 Acting on hydrogen as donor
- 12.1 EC 1.12.1 With NAD or NADP as acceptor
- 12.2 EC 1.12.2 With a cytochrome as acceptor
- 12.3 EC 1.12.5 With a quinone or similar compound as acceptor
- 12.4 EC 1.12.7 With an iron-sulfur protein as acceptor
- 12.5 EC 1.12.98 With other known acceptors
- 12.6 EC 1.12.99 With other acceptors
13 EC 1.13 Acting on single donors with incorporation of molecular oxygen (oxygenases)
- 13.1 EC 1.13.1 (transferred to EC 1.13.11)
- 13.2 EC 1.13.11 With incorporation of two atoms of oxygen
- 13.3 EC 1.13.12 With incorporation of one atom of oxygen (internal monooxygenases or internal mixed function oxidases)
- 13.4 EC 1.13.99 Miscellaneous
14 EC 1.14 Acting on paired donors, with incorporation or reduction of molecular oxygen
- 14.1 EC 1.14.1 With NADH or NADPH as one donor (deleted sub-subclass)
- 14.2 EC 1.14.2 With ascorbate as one donor (deleted sub-subclass)
- 14.3 EC 1.14.3 With reduced pteridine as one donor (deleted sub-subclass)
- 14.4 EC 1.14.11 With 2-oxoglutarate as one donor, and incorporation of one atom each of oxygen into both donors
- 14.5 EC 1.14.12 With NADH or NADPH as one donor, and incorporation of two atoms of oxygen into one donor
- 14.6 EC 1.14.13 With NADH or NADPH as one donor, and incorporation of one atom of oxygen
- 14.7 EC 1.14.14 With reduced flavin or flavoprotein as one donor, and incorporation of one atom of oxygen
- 14.8 EC 1.14.15 With reduced iron-sulfur protein as one donor, and incorporation of one atom of oxygen
- 14.9 EC 1.14.16 With reduced pteridine as one donor, and incorporation of one atom of oxygen
- 14.10 EC 1.14.17 With reduced ascorbate as one donor, and incorporation of one atom of oxygen
- 14.11 EC 1.14.18 With another compound as one donor, and incorporation of one atom of oxygen
- 14.12 EC 1.14.19 With oxidation of a pair of donors resulting in the reduction of molecular oxygen to two molecules of water
- 14.13 EC 1.14.20 With 2-oxoglutarate as one donor, and the other dehydrogenated
- 14.14 EC 1.14.21 With NADH or NADPH as one donor, and the other dehydrogenated
- 14.15 EC 1.14.99 Miscellaneous
15 EC 1.15 Acting on superoxide as acceptor
- 15.1 EC 1.15.1
16 EC 1.16 Oxidizing metal ions
- 16.1 EC 1.16.1 With NAD or NADP as acceptor
- 16.2 EC 1.16.3 With oxygen as acceptor
- 16.3 EC 1.16.5 With ascorbate as acceptor
- 16.4 EC 1.16.8 With flavin as acceptor
- 16.5 EC 1.16.9 With rusticyanin as acceptor
- 16.6 EC 1.16.98 With rusticyanin as acceptor
17 EC 1.17 Acting on CH or CH₂ groups
- 17.1 EC 1.17.1 With NAD or NADP as acceptor
- 17.2 EC 1.17.2 With MCD as acceptor
- 17.3 EC 1.17.3 With oxygen as acceptor
- 17.4 EC 1.17.4 With a disulfide as acceptor
- 17.5 EC 1.17.5 With a quinone or similar compound as acceptor
- 17.6 EC 1.17.7 With an iron-sulfur protein as acceptor
- 17.7 EC 1.17.99 With other acceptors
18 EC 1.18 Acting on iron-sulfur proteins as donors
- 18.1 EC 1.18.1 With NAD⁺ or NADP⁺ as acceptor
- 18.2 EC 1.18.2 With dinitrogen as acceptor (transferred to EC 1.18.6)
- 18.3 EC 1.18.3 With H⁺ as acceptor
- 18.4 EC 1.18.6 With dinitrogen as acceptor
- 18.5 EC 1.18.96 With other, known, acceptors
- 18.6 EC 1.18.99 With H⁺ as acceptor
19 EC 1.19 Acting on reduced flavodoxin as donor
- 19.1 EC 1.19.6 With dinitrogen as acceptor
20 EC 1.20 Acting on phosphorus or arsenic in donors
- 20.1 EC 1.20.1 Acting on phosphorus or arsenic in donors, with NAD⁺ as acceptor
- 20.2 EC 1.20.2 Acting on phosphorus or arsenic in donors, with NAD(P)⁺ as acceptor
- 20.3 EC 1.20.4 Acting on phosphorus or arsenic in donors, with disulfide as acceptor
- 20.4 EC 1.20.9 Acting on phosphorus or arsenic in donors, with azurin acceptors
- 20.5 EC 1.20.98 Acting on phosphorus or arsenic in donors, with other, known acceptors
- 20.6 EC 1.20.99 Acting on phosphorus or arsenic in donors, with other acceptors
21 EC 1.21 Acting on X-H and Y-H to form an X-Y bond
- 21.1 EC 1.21.3 With oxygen as acceptor
- 21.2 EC 1.21.4 With a disulfide as acceptor
- 21.3 EC 1.21.99 With other acceptors
22 EC 1.22 Acting on halogen in donors
- 22.1 EC 1.22.1 With NAD⁺ or NADP⁺ as acceptor
23 EC 1.97 Other oxidoreductases
- 23.1 EC 1.97.1
24 EC 1.98 Enzymes using H₂ as reductant
- 24.1 EC 1.98.1
25 EC 1.99 Other enzymes using O₂ as oxidant
- 25.1 EC 1.99.1 Hydroxylases (now covered by EC 1.14)
- 25.2 EC 1.99.2 Oxygenases (now covered by EC 1.13)

EC 1.1 Acting on the CH-OH group of donors

EC 1.1.1 With NAD or NADP as acceptor

EC 1.1.2 With a cytochrome as acceptor

EC 1.1.3 With oxygen as acceptor

EC 1.1.3.1: deleted, included in *EC 1.1.3.15
EC 1.1.3.2: now *EC 1.13.12.4
EC 1.1.3.3: malate oxidase
EC 1.1.3.4: glucose oxidase
EC 1.1.3.5: hexose oxidase
EC 1.1.3.6: cholesterol oxidase
EC 1.1.3.7: aryl-alcohol oxidase
EC 1.1.3.8: L-gulonolactone oxidase
EC 1.1.3.9: galactose oxidase
EC 1.1.3.10: pyranose oxidase
EC 1.1.3.11: L-sorbose oxidase
EC 1.1.3.12: pyridoxine 4-oxidase
EC 1.1.3.13: alcohol oxidase
EC 1.1.3.14: catechol oxidase (dimerizing)
EC 1.1.3.15: (S)-2-hydroxy-acid oxidase
EC 1.1.3.16: ecdysone oxidase
EC 1.1.3.17: choline oxidase
EC 1.1.3.18: Secondary-alcohol oxidase
EC 1.1.3.19: 4-hydroxymandelate oxidase
EC 1.1.3.20: long-chain-alcohol oxidase
EC 1.1.3.21: glycerol-3-phosphate oxidase
EC 1.1.3.22: now *EC 1.17.3.2
EC 1.1.3.23: Thiamine oxidase
EC 1.1.3.24: L-galactonolactone oxidase
EC 1.1.3.25: now included with *EC 1.1.99.18
EC 1.1.3.26: now *EC 1.21.3.2
EC 1.1.3.27: hydroxyphytanate oxidase
EC 1.1.3.28: nucleoside oxidase
EC 1.1.3.29: N-acylhexosamine oxidase
EC 1.1.3.30: polyvinyl-alcohol oxidase
EC 1.1.3.31: deleted
EC 1.1.3.32: now *EC 1.14.21.1
EC 1.1.3.33: now *EC 1.14.21.2
EC 1.1.3.34: now *EC 1.14.21.3
EC 1.1.3.35: now *EC 1.14.21.4
EC 1.1.3.36: now *EC 1.14.21.5
EC 1.1.3.37: D-arabinono-1,4-lactone oxidase
EC 1.1.3.38: vanillyl-alcohol oxidase
EC 1.1.3.39: nucleoside oxidase (H₂O₂-forming)
EC 1.1.3.40: D-mannitol oxidase
EC 1.1.3.41: xylitol oxidase
EC 1.1.3.42: prosolanapyrone-II oxidase
EC 1.1.3.43: paromamine 6'-oxidase
EC 1.1.3.44: 6-Hydroxyneomycin C oxidase

EC 1.1.4 With a disulfide as acceptor

EC 1.1.5 With a quinone or similar compound as acceptor

EC 1.1.5.1: deleted, see EC 1.1.99.18 cellobiose dehydrogenase (acceptor)
EC 1.1.5.2: quinoprotein glucose dehydrogenase
EC 1.1.5.3: glycerol-3-phosphate dehydrogenase (quinone)
EC 1.1.5.4: malate dehydrogenase (quinone)
EC 1.1.5.5: alcohol dehydrogenase (quinone)
EC 1.1.5.6: formate dehydrogenase-N
EC 1.1.5.7: cyclic alcohol dehydrogenase (quinone)
EC 1.1.5.8: quinate dehydrogenase (quinone)

EC 1.1.9 With a copper protein as acceptor

EC 1.1.9.1: alcohol dehydrogenase (azurin)

EC 1.1.98 With other, known, acceptors

EC 1.1.99 With other acceptors

EC 1.2 Acting on the aldehyde or oxo group of donors

EC 1.2.1 With NAD or NADP as acceptor

EC 1.2.2 With a cytochrome as acceptor

EC 1.2.7 With an iron-sulfur protein as acceptor

EC 1.2.99 With other acceptors

EC 1.3 Acting on the CH-CH group of donors

EC 1.3.1 With NAD or NADP as acceptor

EC 1.3.2 With a cytochrome as acceptor

EC 1.3.2.1: now EC 1.3.99.2
EC 1.3.2.2: now EC 1.3.99.3
EC 1.3.2.3: galactonolactone dehydrogenase

EC 1.3.3 With oxygen as acceptor

EC 1.3.5 With a quinone or related compound as acceptor

EC 1.3.7 With an iron-sulfur protein as acceptor

EC 1.3.8 With an FAD as prosthetic group

EC 1.3.98 With FMN acceptor

EC 1.3.98.1: dihydroorotate dehydrogenase (fumarate)

EC 1.3.99 With other acceptors

EC 1.4 Acting on the CH-NH₂ group of donors

EC 1.4.1 With NAD or NADP as acceptor

EC 1.4.2 With a cytochrome as acceptor

EC 1.4.2.1: glycine dehydrogenase (cytochrome)

EC 1.4.3 With oxygen as acceptor

EC 1.4.3.1: D-aspartate oxidase
EC 1.4.3.2: L-amino-acid oxidase
EC 1.4.3.3: D-amino-acid oxidase
EC 1.4.3.4: amine oxidase (flavin-containing)
EC 1.4.3.5: pyridoxamine-phosphate oxidase
EC 1.4.3.6: amine oxidase (copper-containing)
EC 1.4.3.7: D-glutamate oxidase
EC 1.4.3.8: ethanolamine oxidase
EC 1.4.3.9: deleted, included in *EC 1.4.3.4
EC 1.4.3.10: putrescine oxidase
EC 1.4.3.11: L-glutamate oxidase
EC 1.4.3.12: cyclohexylamine oxidase
EC 1.4.3.13: protein-lysine 6-oxidase
EC 1.4.3.14: L-lysine oxidase
EC 1.4.3.15: D-glutamate(D-aspartate) oxidase
EC 1.4.3.16: L-aspartate oxidase
EC 1.4.3.17: now *EC 1.3.3.10
EC 1.4.3.18: deleted, not approved
EC 1.4.3.19: glycine oxidase
EC 1.4.3.20: L-lysine 6-oxidase
EC 1.4.3.21: primary-amine oxidase
EC 1.4.3.22: diamine oxidase
EC 1.4.3.23: 7-chloro-L-tryptophan oxidase
EC 1.4.3.24: pseudooxynicotine oxidase

EC 1.4.4 With a disulfide as acceptor

EC 1.4.4.1: now EC 1.21.4.1
EC 1.4.4.2: glycine dehydrogenase (decarboxylating)

EC 1.4.5 With an iron-sulfur flavoprotein as acceptor

EC 1.4.5.1: D-amino acid dehydrogenase (quinone)

EC 1.4.7 With an iron-sulfur protein as acceptor

EC 1.4.7.1: glutamate synthase (ferredoxin)

EC 1.4.9 With TTQ acceptors

EC 1.4.98 With tryptophan tryptophylquinone acceptors

EC 1.4.98.1: methylamine dehydrogenase (amicyanin)

EC 1.4.99 With other acceptors

EC 1.5 Acting on the CH-NH group of donors

EC 1.5.1 With NAD or NADP as acceptor

EC 1.5.3 With oxygen as acceptor

EC 1.5.3.1: sarcosine oxidase
EC 1.5.3.2: N-methyl-L-amino-acid oxidase
EC 1.5.3.3: deleted
EC 1.5.3.4: N6-methyl-lysine oxidase
EC 1.5.3.5: (S)-6-hydroxynicotine oxidase
EC 1.5.3.6: (R)-6-hydroxynicotine oxidase
EC 1.5.3.7: L-pipecolate oxidase
EC 1.5.3.8: deleted, included in *EC 1.3.3.8
EC 1.5.3.9: now *EC 1.21.3.3
EC 1.5.3.10: dimethylglycine oxidase
EC 1.5.3.11: polyamine oxidase
EC 1.5.3.12: dihydrobenzophenanthridine oxidase
EC 1.5.3.13: N1-acetylpolyamine oxidase
EC 1.5.3.14: polyamine oxidase (propane-1,3-diamine-forming)
EC 1.5.3.15: N8-acetylspermidine oxidase (propane-1,3-diamine-forming)
EC 1.5.3.16: spermine oxidase
EC 1.5.3.17: non-specific polyamine oxidase
EC 1.5.3.18: L-saccharopine oxidase
EC 1.5.3.19: 4-methylaminobutanoate oxidase (formaldehyde-forming)
EC 1.5.3.20: N-alkylglycine oxidase
EC 1.5.3.21: 4-methylaminobutanoate oxidase (methylamine-forming)

EC 1.5.4 With a disulfide as acceptor

EC 1.5.4.1: pyrimidodiazepine synthase

EC 1.5.5 With a quinone or similar compound as acceptor

EC 1.5.5.1: electron-transferring-flavoprotein dehydrogenase

EC 1.5.7 With an iron-sulfur protein as acceptor

EC 1.5.7.1: methylenetetrahydrofolate reductase (ferredoxin)

EC 1.5.8 With a flavin as acceptor

EC 1.5.99 With other acceptors

EC 1.6 Acting on NADH or NADPH

EC 1.6.1 With NAD or NADP as acceptor

EC 1.6.2 With a heme protein as acceptor

EC 1.6.2.1: now EC 1.6.99.3
EC 1.6.2.2: cytochrome-b5 reductase
EC 1.6.2.3: deleted
EC 1.6.2.4: NADPH—hemoprotein reductase
EC 1.6.2.5: NADPH—cytochrome-c2 reductase
EC 1.6.2.6: leghemoglobin reductase

EC 1.6.3 With oxygen as acceptor

EC 1.6.3.1: NAD(P)H oxidase

EC 1.6.4 With a disulfide as acceptor

EC 1.6.5 With a quinone or similar compound as acceptor

EC 1.6.6 With a nitrogenous group as acceptor

EC 1.6.6.1: now *EC 1.7.1.1
EC 1.6.6.2: now *EC 1.7.1.2
EC 1.6.6.3: now *EC 1.7.1.3
EC 1.6.6.4: now *EC 1.7.1.4
EC 1.6.6.5: now *EC 1.7.99.3
EC 1.6.6.6: now *EC 1.7.1.5
EC 1.6.6.7: now *EC 1.7.1.6
EC 1.6.6.8: now *EC 1.7.1.7
EC 1.6.6.9: trimethylamine-N-oxide reductase
EC 1.6.6.10: now *EC 1.7.1.9
EC 1.6.6.11: now *EC 1.7.1.10
EC 1.6.6.12: now *EC 1.7.1.11
EC 1.6.6.13: now *EC 1.7.1.12

EC 1.6.7 With an iron-sulfur protein as acceptor

EC 1.6.7.1: now EC 1.18.1.2
EC 1.6.7.2: now EC 1.18.1.1

EC 1.6.8 With a flavin as acceptor

EC 1.6.8.1: now EC 1.5.1.29
EC 1.6.8.2: now EC 1.5.1.30

EC 1.6.99 With other acceptors

EC 1.6.99.1: NADPH dehydrogenase
EC 1.6.99.2: now *EC 1.6.5.2
EC 1.6.99.3: NADH dehydrogenase
EC 1.6.99.4: now *EC 1.18.1.2
EC 1.6.99.5: NADH dehydrogenase (quinone)
EC 1.6.99.6: NADPH dehydrogenase (quinone)
EC 1.6.99.7: now *EC 1.5.1.34
EC 1.6.99.8: now *EC 1.16.1.3
EC 1.6.99.9: now *EC 1.16.1.4
EC 1.6.99.10: deleted, included in *EC 1.6.99.7
EC 1.6.99.11: now *EC 1.16.1.5
EC 1.6.99.12: now *EC 1.16.1.6
EC 1.6.99.13: now *EC 1.16.1.7

EC 1.7 Acting on other nitrogenous compounds as donors

EC 1.7.1 With NAD⁺ or NADP⁺ as acceptor

EC 1.7.2 With a cytochrome as acceptor

EC 1.7.3 With oxygen as acceptor

EC 1.7.5 With miscellaneous acceptora

EC 1.7.6 With hydrogen as acceptor

EC 1.7.6.1: nitrite dismutase

EC 1.7.7 With an iron-sulfur protein as acceptor

EC 1.7.99 With other acceptors

EC 1.7.99.1: hydroxylamine reductase
EC 1.7.99.2: deleted
EC 1.7.99.3: included with *EC 1.7.2.1
EC 1.7.99.4: nitrate reductase
EC 1.7.99.5: deleted, now included with *EC 1.5.1.20
EC 1.7.99.6: nitrous-oxide reductase
EC 1.7.99.7: nitric-oxide reductase
EC 1.7.99.8: hydroxylamine oxidoreductase

EC 1.8 Acting on a sulfur group of donors

EC 1.8.1 With NAD or NADP as acceptor

EC 1.8.2 With a cytochrome as acceptor

EC 1.8.3 With oxygen as acceptor

EC 1.8.4 With a disulfide as acceptor

EC 1.8.5 With a quinone or similar compound as acceptor

EC 1.8.6 With a nitrogenous group as acceptor

EC 1.8.6.1: deleted, included in EC 2.5.1.18

EC 1.8.7 With an iron-sulfur protein as acceptor

EC 1.8.98 With other, known, acceptors

EC 1.8.99 With other acceptors

EC 1.9 Acting on a heme group of donors

EC 1.9.3 With oxygen as acceptor

EC 1.9.3.1: cytochrome-c oxidase
EC 1.9.3.2: included with EC 1.7.2.1

EC 1.9.6 With a nitrogenous group as acceptor

EC 1.9.6.1: nitrate reductase (cytochrome)

EC 1.9.99 With other acceptors

EC 1.9.99.1: iron—cytochrome-c reductase

EC 1.10 Acting on diphenols and related substances as donors

EC 1.10.1 With NAD or NADP as acceptor

EC 1.10.1.1: trans-acenaphthene-1,2-diol dehydrogenase

EC 1.10.2 With a cytochrome as acceptor

EC 1.10.3 With oxygen as acceptor

EC 1.10.3.1: catechol oxidase
EC 1.10.3.2: laccase
EC 1.10.3.3: L-ascorbate oxidase
EC 1.10.3.4: o-aminophenol oxidase
EC 1.10.3.5: 3-hydroxyanthranilate oxidase
EC 1.10.3.6: rifamycin-B oxidase
EC 1.10.3.7: now EC 1.21.3.4
EC 1.10.3.8: now EC 1.21.3.5
EC 1.10.3.9: photosystem II
EC 1.10.3.10: ubiquinol oxidase (H⁺-transporting)
EC 1.10.3.11: ubiquinol oxidase
EC 1.10.3.12: menaquinol oxidase (H⁺-transporting)

EC 1.10.99 With plastocyanin acceptors

EC 1.10.9.1: plastoquinol---plastocyanin reductase

EC 1.10.99 With other acceptors

EC 1.11 Acting on a peroxide as acceptor

EC 1.11.1 Peroxidases

EC 1.11.2 Peroxygenase

EC 1.12 Acting on hydrogen as donor

EC 1.12.1 With NAD or NADP as acceptor

EC 1.12.2 With a cytochrome as acceptor

EC 1.12.2.1: cytochrome-c3 hydrogenase

EC 1.12.5 With a quinone or similar compound as acceptor

EC 1.12.5.1: hydrogen:quinone oxidoreductase

EC 1.12.7 With an iron-sulfur protein as acceptor

EC 1.12.7.1: now EC 1.18.99.1
EC 1.12.7.2: ferredoxin hydrogenase

EC 1.12.98 With other known acceptors

EC 1.12.99 With other acceptors

EC 1.12.99.1: now *EC 1.12.98.1
EC 1.12.99.2: deleted, composed of *EC 1.12.98.3 and *EC 1.8.98.1
EC 1.12.99.3: now *EC 1.12.5.1
EC 1.12.99.4: now *EC 1.12.98.2
EC 1.12.99.5: identical to *EC 1.13.11.47
EC 1.12.99.6: hydrogenase (acceptor)

EC 1.13 Acting on single donors with incorporation of molecular oxygen (oxygenases)

EC 1.13.1 (transferred to EC 1.13.11)

EC 1.13.11 With incorporation of two atoms of oxygen

EC 1.13.12 With incorporation of one atom of oxygen (internal monooxygenases or internal mixed function oxidases)

EC 1.13.99 Miscellaneous

EC 1.14 Acting on paired donors, with incorporation or reduction of molecular oxygen

EC 1.14.1 With NADH or NADPH as one donor (deleted sub-subclass)

EC 1.14.1.1: now EC 1.14.14.1
EC 1.14.1.2: now EC 1.14.13.9
EC 1.14.1.3: deleted, covered by EC 1.14.99.7, EC 5.4.99.7
EC 1.14.1.4: now EC 1.14.99.2
EC 1.14.1.5: now EC 1.14.13.5
EC 1.14.1.6: now EC 1.14.15.4
EC 1.14.1.7: now EC 1.14.99.9
EC 1.14.1.8: now EC 1.14.99.10
EC 1.14.1.9: deleted
EC 1.14.1.10: now EC 1.14.99.11
EC 1.14.1.11: deleted

EC 1.14.2 With ascorbate as one donor (deleted sub-subclass)

EC 1.14.2.1: now EC 1.14.17.1
EC 1.14.2.2: now EC 1.13.11.27

EC 1.14.3 With reduced pteridine as one donor (deleted sub-subclass)

EC 1.14.3.1: now EC 1.14.16.1

EC 1.14.11 With 2-oxoglutarate as one donor, and incorporation of one atom each of oxygen into both donors

EC 1.14.12 With NADH or NADPH as one donor, and incorporation of two atoms of oxygen into one donor

EC 1.14.13 With NADH or NADPH as one donor, and incorporation of one atom of oxygen

EC 1.14.14 With reduced flavin or flavoprotein as one donor, and incorporation of one atom of oxygen

EC 1.14.14.1: unspecific monooxygenase
EC 1.14.14.2: deleted, included in EC 1.14.14.1
EC 1.14.14.3: alkanal monooxygenase (FMN-linked)
EC 1.14.14.4: deleted, identical to EC 1.14.15.7
EC 1.14.14.5: alkanesulfonate monooxygenase
EC 1.14.14.6: Now EC 1.14.13.111
EC 1.14.14.7: tryptophan 7-halogenase
EC 1.14.14.8: anthranilate 3-monooxygenase (FAD)
EC 1.14.14.9: 4-hydroxyphenylacetate 3-monooxygenase
EC 1.14.14.10: nitrilotriacetate monooxygenase
EC 1.14.14.11: styrene monooxygenase
EC 1.14.14.12: 3-hydroxy-9,10-secoandrosta-1,3,5(10)-triene-9,17-dione monooxygenase
EC 1.14.14.13: 4-(gamma-L-glutamylamino)butanoyl-(BtrI acyl-carrier protein) monooxygenase

EC 1.14.15 With reduced iron-sulfur protein as one donor, and incorporation of one atom of oxygen

EC 1.14.16 With reduced pteridine as one donor, and incorporation of one atom of oxygen

EC 1.14.17 With reduced ascorbate as one donor, and incorporation of one atom of oxygen

EC 1.14.17.1: dopamine b-monooxygenase
EC 1.14.17.2: deleted, included in EC 1.14.18.1
EC 1.14.17.3: peptidylglycine monooxygenase
EC 1.14.17.4: aminocyclopropanecarboxylate oxidase

EC 1.14.18 With another compound as one donor, and incorporation of one atom of oxygen

EC 1.14.19 With oxidation of a pair of donors resulting in the reduction of molecular oxygen to two molecules of water

EC 1.14.20 With 2-oxoglutarate as one donor, and the other dehydrogenated

EC 1.14.21 With NADH or NADPH as one donor, and the other dehydrogenated

EC 1.14.99 Miscellaneous

EC 1.15 Acting on superoxide as acceptor

EC 1.15.1

EC 1.16 Oxidizing metal ions

EC 1.16.1 With NAD or NADP as acceptor

EC 1.16.3 With oxygen as acceptor

EC 1.16.3.1: ferroxidase

EC 1.16.5 With ascorbate as acceptor

EC 1.16.5.1: ascorbate ferrireductase (transmembrane)

EC 1.16.8 With flavin as acceptor

EC 1.16.8.1: cob(II)yrinic acid a,c-diamide reductase

EC 1.16.9 With rusticyanin as acceptor

EC 1.16.9.1: iron:rusticyanin reductase

EC 1.16.98 With rusticyanin as acceptor

EC 1.16.98.1: Now EC 1.16.9.1

EC 1.17 Acting on CH or CH₂ groups

EC 1.17.1 With NAD or NADP as acceptor

EC 1.17.2 With MCD as acceptor

EC 1.17.3 With oxygen as acceptor

EC 1.17.4 With a disulfide as acceptor

EC 1.17.5 With a quinone or similar compound as acceptor

EC 1.17.7 With an iron-sulfur protein as acceptor

EC 1.17.99 With other acceptors

EC 1.18 Acting on iron-sulfur proteins as donors

EC 1.18.1 With NAD⁺ or NADP⁺ as acceptor

EC 1.18.2 With dinitrogen as acceptor (transferred to EC 1.18.6)

EC 1.18.2.1: now EC 1.18.6.1

EC 1.18.3 With H⁺ as acceptor

EC 1.18.3.1: now EC 1.18.99.1

EC 1.18.6 With dinitrogen as acceptor

EC 1.18.6.1: nitrogenase

EC 1.18.96 With other, known, acceptors

EC 1.18.96.1: now EC 1.15.1.2

EC 1.18.99 With H⁺ as acceptor

EC 1.18.99.1: now EC 1.12.7.2

EC 1.19 Acting on reduced flavodoxin as donor

EC 1.19.6 With dinitrogen as acceptor

EC 1.19.6.1: nitrogenase (flavodoxin)

EC 1.20 Acting on phosphorus or arsenic in donors

EC 1.20.1 Acting on phosphorus or arsenic in donors, with NAD⁺ as acceptor

EC 1.20.1.1: phosphonate dehydrogenase

EC 1.20.2 Acting on phosphorus or arsenic in donors, with NAD(P)⁺ as acceptor

EC 1.20.2.1: arsenate reductase (cytochrome c)

EC 1.20.4 Acting on phosphorus or arsenic in donors, with disulfide as acceptor

EC 1.20.9 Acting on phosphorus or arsenic in donors, with azurin acceptors

EC 1.20.9.1: arsenate reductase (azurin)

EC 1.20.98 Acting on phosphorus or arsenic in donors, with other, known acceptors

EC 1.20.98.1: Now EC 1.20.9.1

EC 1.20.99 Acting on phosphorus or arsenic in donors, with other acceptors

EC 1.20.99.1: arsenate reductase (donor)

EC 1.21 Acting on X-H and Y-H to form an X-Y bond

EC 1.21.3 With oxygen as acceptor

EC 1.21.4 With a disulfide as acceptor

EC 1.21.99 With other acceptors

EC 1.21.99.1: b-cyclopiazonate dehydrogenase

EC 1.22 Acting on halogen in donors

EC 1.22.1 With NAD⁺ or NADP⁺ as acceptor

EC 1.22.1.1: iodotyrosine deiodinase

EC 1.97 Other oxidoreductases

EC 1.97.1

EC 1.97.1.1: chlorate reductase
EC 1.97.1.2: pyrogallol hydroxytransferase
EC 1.97.1.3: sulfur reductase
EC 1.97.1.4: (formate-C-acetyltransferase)-activating enzyme
EC 1.97.1.5: now *EC 1.20.4.1
EC 1.97.1.6: now *EC 1.20.99.1
EC 1.97.1.7: now *EC 1.20.4.2
EC 1.97.1.8: tetrachloroethene reductive dehalogenase
EC 1.97.1.9: selenate reductase
EC 1.97.1.10: thyroxine 5'-deiodinase
EC 1.97.1.11: thyroxine 5-deiodinase
EC 1.97.1.12: photosystem I

EC 1.98 Enzymes using H₂ as reductant

EC 1.98.1

EC 1.98.1.1: now EC 1.18.99.1

EC 1.99 Other enzymes using O₂ as oxidant

EC 1.99.1 Hydroxylases (now covered by EC 1.14)

EC 1.99.1.1: deleted, now *EC 1.14.14.1
EC 1.99.1.2: deleted, now *EC 1.14.16.1
EC 1.99.1.3: deleted
EC 1.99.1.4: deleted
EC 1.99.1.5: deleted, now *EC 1.14.13.9
EC 1.99.1.6: deleted
EC 1.99.1.7: deleted, now *EC 1.14.15.4
EC 1.99.1.8: deleted
EC 1.99.1.9: deleted, now *EC 1.14.99.9
EC 1.99.1.10: deleted
EC 1.99.1.11: deleted, now *EC 1.14.99.10
EC 1.99.1.12: deleted
EC 1.99.1.13: deleted, covered by *EC 1.14.99.7 and *EC 5.4.99.7
EC 1.99.1.14: deleted, now *EC 1.13.11.27

EC 1.99.2 Oxygenases (now covered by EC 1.13)

EC 1.99.2.1: deleted, now *EC 1.13.11.12
EC 1.99.2.2: deleted, now *EC 1.13.11.1
EC 1.99.2.3: deleted, now *EC 1.13.11.3
EC 1.99.2.4: deleted, now *EC 1.13.11.4
EC 1.99.2.5: deleted, now *EC 1.13.11.5
EC 1.99.2.6: deleted, now *EC 1.13.99.1

Molecular and Cellular Biology portal

v t e Aldehyde/oxo oxidoreductases (EC 1.2)
1.2.1: NAD or NADP	Aldehyde dehydrogenase Acetaldehyde dehydrogenase Long-chain-aldehyde dehydrogenase
1.2.2: cytochrome	Formate dehydrogenase (cytochrome)
1.2.3: oxygen	Aldehyde oxidase
1.2.4: disulfide	Oxoglutarate dehydrogenase complex Pyruvate dehydrogenase Branched-chain alpha-keto acid dehydrogenase complex BCKDHA BCKDHB DBT DLD
1.2.7: iron-sulfur protein	Pyruvate synthase

v t e CH-NH₂ oxidoreductases (EC 1.4) - primarily amino acid oxidoreductases
1.4.1: NAD/NADP acceptor	Glutamate dehydrogenase GLUD1 GLUD2 Glutamate synthase (NADPH)
1.4.3: oxygen acceptor	D-amino acid oxidase Amine oxidase (Copper-containing (Lysyl Diamine Primary-amine)) (Flavin-containing (Monoamine)))
1.4.4: disulfide acceptor	Glycine cleavage system
1.4.99: other acceptors	D-amino acid dehydrogenase Amine dehydrogenase

v t e Oxidoreductases: CH-NH (EC 1.5)
1.5.1: NAD or NADP acceptor	Dihydrofolate reductase Saccharopine dehydrogenase Methylenetetrahydrofolate reductase
1.5.3: oxygen acceptor	Dihydrobenzophenanthridine oxidase Sarcosine oxidase Proline oxidase
1.5.5: quinone acceptor	Electron-transferring-flavoprotein dehydrogenase
1.5.99	Sarcosine dehydrogenase Cytokinin dehydrogenase

v t e Oxidoreductases: NADH or NADPH (EC 1.6)
1.6.1: NAD/NADP	NAD(P)⁺ transhydrogenase (Si-specific) NAD(P)⁺ transhydrogenase (Re/Si-specific)
1.6.2: Heme	Methemoglobin reductase NADPH—hemoprotein reductase/Cytochrome P450 reductase NADPH—cytochrome-c2 reductase Leghemoglobin reductase
1.6.3: Oxygen	NADPH oxidase P91-PHOX Neutrophil cytosolic factor 1 Neutrophil cytosolic factor 2 Neutrophil cytosolic factor 4 dual oxidase Dual oxidase 1 Dual oxidase 2
1.6.5: Quinone or similar	NADH dehydrogenase
1.6.6: Nitrogenous group	Trimethylamine-N-oxide reductase
1.6.99: other	NADH dehydrogenase (quinone)

v t e Oxidoreductases: sulfur oxidoreductases (EC 1.8)
1.8.1: NAD or NADP	Dihydrolipoamide dehydrogenase Glutathione reductase Thioredoxin reductase
1.8.2: cytochrome	Sulfite dehydrogenase Thiosulfate dehydrogenase
1.8.3: oxygen	Sulfite oxidase
1.8.4: disulfide	Glutathione—homocystine transhydrogenase
1.8.5: quinone	Glutathione dehydrogenase (ascorbate)
1.8.98: Other, known	CoB—CoM heterodisulfide reductase
1.8.99: Other	Sulfite reductase

v t e Oxidoreductases: diphenol family (EC 1.10)
1.10.1	Trans-acenaphthene-1,2-diol dehydrogenase
1.10.2	Coenzyme Q - cytochrome c reductase
1.10.3	Catechol oxidase Laccase
1.10.99	Cytochrome b6f complex
Other	Alternative oxidase

v t e Oxidoreductases: monooxygenases (EC 1.13)
1.13.11: two atoms of oxygen	lipoxygenase: Arachidonate 5-lipoxygenase Arachidonate 12-lipoxygenase/ALOX12 Arachidonate 8-lipoxygenase Arachidonate 15-lipoxygenase/ALOX15 Linoleate 11-lipoxygenase other dioxygenase: Catechol dioxygenase Homogentisate 1,2-dioxygenase Cysteine dioxygenase 4-Hydroxyphenylpyruvate dioxygenase Indoleamine 2,3-dioxygenase Chlorite dismutase
1.13.12: one atom of oxygen	Firefly luciferase
1.13.99: other	Inositol oxygenase

v t e Other oxidoreductases (EC 1.15-1.21)
1.15: Acting on superoxide as acceptor	Superoxide dismutase SOD1 SOD2 SOD3
1.16: Oxidizing metal ions	Ceruloplasmin
1.17: Acting on CH or CH2 groups	Xanthine oxidase Ribonucleotide reductase 4-Hydroxy-3-methylbut-2-enyl diphosphate reductase
1.18: Acting on iron-sulfur proteins as donors	Nitrogenase
1.19: Acting on reduced flavodoxin as donor	Nitrogenase (flavodoxin)
1.20: Acting on phosphorus or arsenic in donors	Glutaredoxin GLRX GLRX2 GLRX3 GLRX5
1.21: Acting on X-H and Y-H to form an X-Y bond	Isopenicillin N synthase Columbamine oxidase Reticuline oxidase Sulochrin oxidase (+)-bisdechlorogeodin-forming (-)-bisdechlorogeodin-forming Aureusidin synthase Tetrahydrocannabinolic acid synthase Cannabidiolic acid synthase Dichlorochromopyrrolate synthase