Mescaline Mexico. Europeans noted use of peyote in Native American religious ceremonies upon early contact, notably by the Huichols in Mexico. Other mescaline-containing cacti such as the San Pedro have a long history of use in South America, from Peru to Ecuador. In traditional peyote preparations, the top of the cactus is cut off, leaving the large tap root along with a ring of green photosynthesizing area to grow new heads. These heads are then dried to make disc-shaped buttons. Buttons are chewed to produce the effects or soaked in water to drink. However, the taste of the cactus is bitter,
Mescaline biosynthetic pathway involving "m"-"O"-methylation and aromatic hydroxylation. Tyrosine and phenylalanine serve as the metabolic precursors to synthesis of mescaline. Tyrosine can either undergo a decarboxylation via tyrosine decarboxylase to generate tyramine and subsequently undergo an oxidation at carbon 3 by a monophenol hydroxylase or first be hydroxylated by tyrosine hydroxylase to form L-DOPA and decarboxylated by DOPA decarboxylase. These create dopamine, which then experiences methylation by a catechol-O-methyltransferase (COMT) by an "S"-adenosyl methionine (SAM)-dependent mechanism. The resulting intermediate is then oxidized again by a hydroxylase enzyme, likely monophenol hydroxylase again, at carbon 5, and methylated by COMT. The product, methylated