Exp030GSreport

In Experiment 016 a racemic mixture of [|adrenaline] is utilized in the reaction [|(lec.18)].



Adrenaline Epinephrine 4-(1-hydroxy-2-(methylamino)ethyl)benzene-1,2-diol



Adrenaline to DOPAL

A racemic solution, consisting of both R and S adrenaline is used in this experiment for several reasons, one of which is simply because it is cheaper. A racemeic mixture can be used because the single chiral center in adrenaline, found on the first carbon on its side chain is destroyed in the process of creating DOPAL. The hydroxyl on the first carbon of the side chain will be replaced with a hydrogen, and the side chain from the amino and on will also be cleaved. The amino will be replaced with a double bonding O to the second carbon on the side chain. The hybridization of the second carbon on the side chain will be a sp2 structure; therfore, the double bonded O, hydrogen, and the rest of the side chain including benzene nucleus will be on the same plane in respect to the this particular carbon.



Some physiological amines are synthesized from tyrosine. In the [|creation of epinephrine], tyrosine is converted into Dihydroxylphenylalanine (L-DOPA) by tyrosine hydroxylase. This is then converted into Dopamine via CO2. Dopamine is synthesized into Norepinephrine by Dopamine B-hydroxylase. Norepinephrine reacts with S-Adenosylmethionine that has a highly reactive methyl group. This hightly reactive methyl group replaces a hydrogen on the amino group creating epinephrine. Dopamine B-hydroxylase is a chiral enzyme, that adds chirality to norepinephrine created from dopamine. The chirality is created on the first carbon in the side chain off of the benzene nucleus. One molecule would be S and the other R. These different, R and S molecules would be different because they would have different properties when interacting with biological receptors. [|Natural epinephrine] occuring in nature is usually R.


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