Bahnmaier A H, Woesle B, Thomas H
Department of Physiological Chemistry, University of Ulm, Germany.
Chirality. 1999;11(2):160-5. doi: 10.1002/(SICI)1520-636X(1999)11:2<160::AID-CHIR13>3.0.CO;2-M.
Stereospecific N-methylation of the tetrahydroisoquinoline alkaloids isosalsoline (7-hydroxy-6-methoxy-1-methyl-1,2,3,4-tetrahydroisoquinoline) and salsolidine (6,7-dimethoxy-1-methyl-1,2,3,4-tetrahydroisoquinoline) by amine N-methyltransferase A isolated from bovine liver is reported. Incubation with S-adenosylmethionine as cosubstrate revealed that in case of isosalsoline, an endogenous tetrahydroisoquinoline alkaloid, the (+)-(R)-enantiomer, is preferentially methylated, whereas in the case of salsolidine the (-)-(S)-enantiomer is preferentially methylated. The results were obtained by using two independent methods, namely a radioassay and HPLC following separate incubation experiments.
