In enzymology, (RS)-norcoclaurine 6-O-methyltransferase () is an enzyme that catalyzes the chemical reaction:
In this methylation reaction, the enzyme uses the cofactor, S-adenosyl methionine (SAM) which transfers a methyl group, giving S-adenosyl-L-homocysteine (SAH) as a by-product.
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:(RS)-norcoclaurine 6-O-methyltransferase. This enzyme participates in alkaloid biosynthesis.