Catechol side chain chemistry

COMT is widely distributed in the body and is primarily found on the outer plasma membrane of cells. Even red blood cells have the enzyme. As with PNMT, S-adenosylme-thionine is the source of the methyl group. The enzyme s specificity is toward the catechol nucleus the side chain chemistry seems irrelevant. It is only the meta-OH that is methylated. Magnesium is a requirement. 

The aforementioned protecting groups are chemically stable and are well suited for multi-step chemistries. Alternatively, borate forms complexes with the catechol side chain at an elevated pH and is suitable for functioning as a temporary protecting group for chemical reactions carried out in a basic... 

Although the data above established that NAcDEE could undergo an a,p-desaturation on the side chain following oxidation to the quinone, we felt it desirable to see whether further information could be gleaned about the mechanism and rate of synthesis, since we were interested in this reaction as a model for the reactivity of peptidyl DOPA. The chemistry of catechols and their quinones is notoriously complex, and it was not obvious that a realistic extrapolation from this low molecular... 

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