O-Methylating Enzymes of Dopamine and Dopamine Derived Tetrahydroisoquinoline, Salsolinol

Abstract

By using an LC/API-MS system, it was demonstrated that dopamine condenses with acetaldehyde to give
salsolinol which is further metabolized to produce 6-O-methylsalsolinol (isosalsoline) which is O- and N-methylated to
provide salsolidine and N-methylisosalsoline, respectively, in several plant tissue cultures of Papaveraceae. Almost
none of the 3-O-methoxytyramine formed from dopamine was metabolized into simple isoquinoline derivatives.
Although salsolinol and 3-O-methoxytyramine were formed from dopamine, no O-methylatedsalsolinol was formed in
tissue cultures of Cynanchum vincetoxicum (Asclepiadaceae). The results suggest that the O-methylating enzymes of
salsolinol may be different to those of dopamine.