Isoorientin 3'-O-methyltransferase (EC 2.1.1.78) is an enzyme that catalyzes the chemical reaction:
S-adenosyl-L-methionine + isoorientin ⇌ S-adenosyl-L-homocysteine + isoscoparin
This is a methylation reaction in which the luteolin-6-C-glucoside, isoorientin, is converted to isoscoparin. The methyl group is donated by the cofactor S-adenosyl methionine (SAM), which is converted to S-adenosyl-L-homocysteine (SAH).
Classification: This enzyme belongs to the family of transferases, specifically those transferring one-carbon groups (methyltransferases).
Systematic name: S-adenosyl-L-methionine:isoorientin 3'-O-methyltransferase
Other names: Isoorientin 3'-methyltransferase
Identifiers:
- EC number: 2.1.1.78
- CAS number: 83061-51-2
Reaction specificity: The enzyme also acts on isoorientin 2''-O-rhamnoside and is involved in the biosynthesis of flavones.
References:
- Van Brederode, J.; Kamps-Heinsbroek, R.; Mastenbroek, O. (1982). "Biochemical and Ontogenetic Evidence that the Ferulic Acid and Isoscoparin Formation in Silene are Catalyzed by Different Enzymes". Zeitschrift für Pflanzenphysiologie. 106: 43–53. doi:10.1016/S0044-328X(82)80053-6.
- KEGG Pathway Database, Enzyme 2.1.1.78.
