O-methylated flavonoid

The O-methylated flavonoids or methoxyflavonoids are flavonoids with methylations on hydroxyl groups (methoxy bonds). O-methylation has an effect on the solubility of flavonoids.

Enzymes
O-methylated flavonoids formation implies the presence of specific O-methyltransferase (OMT) enzymes which accept a variety of substrates. Those enzymes mediate the O-methylation on a specific hydroxyl group, like on 4' (example in Catharanthus roseus ) or 3' (example in rice ) positions. Those positions can be ortho, meta, para and there can be a special 3-O-methyltransferase for the 3-OH position. Calamondin orange (Citrus mitis) exhibits all of those activities.

Plant enzymes

 * Apigenin 4'-O-methyltransferase
 * 8-hydroxyquercetin 8-O-methyltransferase
 * Isoflavone 4'-O-methyltransferase
 * Isoflavone 7-O-methyltransferase
 * Isoliquiritigenin 2'-O-methyltransferase
 * Isoorientin 3'-O-methyltransferase
 * Kaempferol 4'-O-methyltransferase
 * Luteolin O-methyltransferase
 * Methylquercetagetin 6-O-methyltransferase
 * 3-methylquercetin 7-O-methyltransferase
 * Myricetin O-methyltransferase
 * Quercetin 3-O-methyltransferase
 * Vitexin 2"-O-rhamnoside 7-O-methyltransferase

Animal enzyme

 * Catechol-O-methyl transferase

O-methylated anthocyanidins

 * 5-Desoxy-malvidin
 * Capensinidin
 * Europinidin
 * Hirsutidin
 * Malvidin
 * Peonidin
 * Petunidin
 * Pulchellidin
 * Rosinidin

O-methylated flavanols

 * Meciadanol (3-O'methyl catechin)

O-methylated flavanones

 * Hesperetin
 * Homoeriodictyol
 * Isosakuranetin
 * Sakuranetin
 * Sterubin

O-methylated flavanonols

 * Dihydrokaempferide

O-methylated flavonols
of kaempferol of myricetin of quercetin other
 * Kaempferide
 * Annulatin
 * Combretol
 * Europetin
 * Laricitrin (3'-O-Dimethylmyricetin)
 * 5-O-methylmyricetin
 * Syringetin (3',5'-O-Dimethylmyricetin)
 * Ayanin
 * Azaleatin
 * Isorhamnetin
 * Ombuin
 * Pachypodol
 * Retusin (quercetin-3,7,3',4'-tetramethyl ether)
 * Rhamnazin
 * Rhamnetin
 * Tamarixetin
 * Eupatolitin
 * Natsudaidain

O-methylated flavones

 * Acacetin
 * Chrysoeriol
 * Diosmetin
 * Nepetin
 * Nobiletin
 * Oroxylin-A
 * Sinensetin
 * Tangeritin
 * Thevetiaflavone
 * Wogonin

O-methylated isoflavones

 * Biochanin A
 * Calycosin
 * Formononetin
 * Glycitein
 * Irigenin
 * 5-O-methylgenistein
 * Pratensein
 * Prunetin
 * Psi-tectorigenin
 * Retusin
 * Tectorigenin