sulfonium ion analogs of the presumptive linalyl and alpha-terpinyl cationic intermediates of the isomerization-cyclization sequence were shown to be potent inhibitors of the enzymatic reaction ( ki = 0.3 and 2.8 microm , respectively ) , and inhibition was synergized by the presence of inorganic pyrophosphate , indicating that the enzyme recognized and bound more tightly to these ion-paired species than to either cationic or anionic partner alone .
C0022023
ion
C0003075
anionic