Methyl-3,4-dimethoxy-5-hydroxyphenethylamine

EXTENSIONS AND COMMENTARY The rationale for exploring the beta-hydroxylated phenethylamines, especially those with oxygens at the biologically important 3- and 4-positions, has already been presented. Norepinephrine is a 6-hydroxylated phenethylamine with oxygens at these two ring positions. With DME, these are masked as two methyl ethers, and the initials DME stand for 3,4-dimethoxyphenyl-B-ethanolamine. This is an alternate name for 3,4-dimethoxy-B-hydroxyphenethylamine. 

Tyramine, hordenine, 3,4-dimethoxy-j8-phenethylamine, jV-methyl-3,4-dimethoxy-j3-hydroxyphenethylamine (86 amorphous a new natural base), salsoline, salsolidine, tryptamine, abrine, and hypa-phorine (54). 

The biosynthetic work on mescaline in the peyote cactus L. williamsii and in the Peruvian cactus T. pachanoi has led to the formulation of biosynthetic pathways according to Scheme 2. A major pathway probably involves decarboxylation of tyrosine followed by hydroxylation to yield dopamine. Dopamine is methylated on the meta hydroxy group to 4-hydroxy-3-methoxyphenethylamine (3-methoxytyramine) which then undergoes hydroxylation to the key intermediate 4,5-dihydroxy-3-methoxyphenethylamine (20). Para-O-methylation of 20 yields 3,4-dimethoxy-5-hydroxyphenethylamine (21), which is the immediate precursor of the main phenolic tetrahydroisoquinolines of peyote. Alternatively, meta-O-methylation yields 3,5-dimethoxy-4-hydroxyphenethylamine (19), which is further efficiently methylated to mescaline. Parallel pathways involving N-methylated compounds probably exist in these cacti (10). 

---