In enzymology, a (RS)-norcoclaurine 6-O-methyltransferase (EC 2.1.1.128) is an enzyme that catalyzes the chemical reaction

S-adenosyl-L-methionine + (RS)-norcoclaurine ${\displaystyle \rightleftharpoons }$ S-adenosyl-L-homocysteine + (RS)-coclaurine

Thus, the two substrates of this enzyme are S-adenosyl methionine and (R,S)-norcoclaurine, whereas its two products are S-adenosylhomocysteine and (R,S)-coclaurine.

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 i.

References

• Rueffer M, Nagakura N, Zenk MH (1983). "Partial purification and properties of S-adenosyl-L-methionine:(R),(S)-norlaudanosoline-6-O-methyltransferase from Argemone platyceras cell cultures". Planta Med. 49 (11): 131–137. doi:10.1055/s-2007-969833. PMID 17405035.
• Sato F, Tsujita T, Katagiri Y, Yoshida S, Yamada Y (1994). "Purification and characterization of S-adenosyl-L-methionine: norcoclaurine 6-O-methyltransferase from cultured Coptis japonica cells". Eur. J. Biochem. 225 (1): 125–31. doi:10.1111/j.1432-1033.1994.00125.x. PMID 7925429.
• Stadler R, Zenk MH (1990). "A revision of the generally accepted pathway for the biosynthesis of the benzyltetrahydroisoquinoline reticuline". Liebigs Ann. Chem.: 555–562. doi:10.1002/jlac.1990199001104.