| EC |
2.1.1.83 |
| Accepted name: |
3,7-dimethylquercetin 4′-O-methyltransferase |
| Reaction: |
S-adenosyl-L-methionine + 5,3′,4′-trihydroxy-3,7-dimethoxyflavone = S-adenosyl-L-homocysteine + 5,3′-dihydroxy-3,7,4′-trimethoxyflavone |
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For diagram of the biosynthesis of methylated quercetin derivatives, click here |
| Other name(s): |
flavonol 4′-O-methyltransferase; flavonol 4′-methyltransferase; 4′-OMT; S-adenosyl-L-methionine:3′,4′,5-trihydroxy-3,7-dimethoxyflavone 4′-O-methyltransferase; 3,7-dimethylquercitin 4′-O-methyltransferase [mis-spelt] |
| Systematic name: |
S-adenosyl-L-methionine:5,3′,4′-trihydroxy-3,7-dimethoxyflavone 4′-O-methyltransferase |
| Comments: |
3,7-Dimethylquercetagetin can also act as acceptor. Involved with EC 2.1.1.76 quercetin 3-O-methyltransferase and EC 2.1.1.82 3-methylquercetin 7-O-methyltransferase in the methylation of quercetin to 3,7,4′-trimethylquercetin in Chrysosplenium americanum. Does not act on flavones, dihydroflavonols, or their glucosides. |
| Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 96477-60-0 |
| References: |
| 1. |
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] |
| 2. |
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] |
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| [EC 2.1.1.83 created 1989] |
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