Medicinal Chemistry

the coenzyme can stabilize the anion by resonance delocalization on the heterocyclic
ring (see figure 8.6). Additionally, flavine-dependent oxidases such as monoamine oxidase
can be attacked by acetylenes as suicide substrates.

8.2.2 Enzyme Targets: Acetylcholinesterase

Acetylcholinesterase (AChE) is the enzyme that hydrolyzes and thereby deactivates
acetycholine (ACh) after it binds to the receptor. The enzyme is present in peripheral
and central synaptic sites, in erythrocytes, and in the placenta.

486 MEDICINAL CHEMISTRY

Figure 8.6 Trifluoroalanine is transformed by a pyridoxal coenzyme into a covalently bound
“suicide substrate.”