| EC |
2.1.1.76 |
| Accepted name: |
quercetin 3-O-methyltransferase |
| Reaction: |
S-adenosyl-L-methionine + 3,5,7,3′,4′-pentahydroxyflavone = S-adenosyl-L-homocysteine + 3-methoxy-5,7,3′,4′-tetrahydroxyflavone |
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For diagram of the biosynthesis of methylated quercetin derivatives, click here |
| Other name(s): |
flavonol 3-O-methyltransferase; flavonoid 3-methyltransferase |
| Systematic name: |
S-adenosyl-L-methionine:3,5,7,3′,4′-pentahydroxyflavone 3-O-methyltransferase |
| Comments: |
Specific for quercetin. Related enzymes bring about the 3-O-methylation of other flavonols, such as galangin and kaempferol. |
| Links to other databases: |
BRENDA, EXPASY, Gene, KEGG, MetaCyc, PDB, CAS registry number: 81295-55-8 |
| References: |
| 1. |
De Luca, V., Brunet, G., Khouri, H., Ibrahim, R. and Hrazdina, G. Flavonol 3-O-methyltransferase in plant-tissues. Z. Naturforsch. 37 (1982) 134–135. |
| 2. |
De Luca, V. and Ibrahim, R.K. Enzymatic synthesis of polymethylated flavonols in Chrysosplenium americanum. I. Partial purification and some properties of S-adenosyl-L-methionine:flavonol 3-, 6-, 7-, and 4′-O-methyltransferases. Arch. Biochem. Biophys. 238 (1985) 596–605. [DOI] [PMID: 3994393] |
| 3. |
De Luca, V. and Ibrahim, R.K. Enzymatic synthesis of polymethylated flavonols in Chrysosplenium americanum. II. Substrate interaction and product inhibition studies of flavonol 3-, 6-, and 4′-O-methyltransferases. Arch. Biochem. Biophys. 238 (1985) 606–618. [DOI] [PMID: 3994394] |
| 4. |
Ibrahim, R.K. and De Luca, V. Polymethylated flavonol synthesis is catalyzed by distinct O-methyltransferases. Naturwissenschaften 69 (1982) 41–42. |
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| [EC 2.1.1.76 created 1984] |
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