The enzymes from Chrysosplenium americanum also methylates 3,7,3'-trimethylquercetagetin at the 6-position. Does not act on flavones, dihydroflavonols, or their glucosides.
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.
Enzymatic synthesis of polymethylated flavonols in Chrysosplenium americanum. II. Substrate interaction and product inhibition studies of flavonol 3-, 6-, and 4'-O-methyltransferases.