In enzymology, a demethylsterigmatocystin 6-O-methyltransferase (EC 184.108.40.206) is an enzyme that catalyzes the chemical reaction
S-adenosyl-L-methionine + 6-demethylsterigmatocystin
S-adenosyl-L-homocysteine + sterigmatocystin
Thus, the two substrates of this enzyme are S-adenosyl methionine and 6-demethylsterigmatocystin, whereas its two products are S-adenosylhomocysteine and sterigmatocystin.
This enzyme belongs to the family of transferases, specifically those transferring one-carbon group methyltransferases. The systematic name of this enzyme class is S-adenosyl-L-methionine:6-demethylsterigmatocystin 6-O-methyltransferase. Other names in common use include demethylsterigmatocystin methyltransferase, and O-methyltransferase I.