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Several studies have described that quinoid rings with electron-rich ole
fins at remote position experiencechanges in their redox potential. Since the original description o
f these changes, di
fferent approacheshave been developed to describe the properties o
f the binding sites o
f ubiquinones. The origin o
f thisphenomenon has been attributed to lateral chain
flexibility and its e
ffect on the recognition betweenproteins and substrates associated with their important biological activity. The use o
f electrochemical-electron spin resonance (EC-ESR) assays and theoretical calculations at MP2/6-31G(d,p) and MP2/6-31++G(d,p)//MP2/6-31G(d,p) levels o
f several con
formers o
f perezone [(2-(1,5-dimethyl-4-hexenyl)-3-hydroxy-5-methyl-1,4-benzoquinone] established that a weak
![](/images/gi<font color=)
fchars/pi.gi
f" BORDER=0 >-
![](/images/gi<font color=)
fchars/pi.gi
f" BORDER=0 > interaction controls not only themolecular con
formation but also its di
ffusion coe
fficient and electrochemical properties. An analogousinteraction can be suggested as the origin o
f similar properties o
f ubiquinone Q
10. The use o
f nuclearmagnetic resonance rendered,
for the
first time, direct evidence o
f the participation o
f di
fferent perezonecon
formers in solution and explained the cycloaddition process observed when the a
forementioned quinoneis heated to
form pipitzols, sesquiterpenes with a cedrene skeleton. The
fact that biological systems canmodulate the redox potential o
f this type o
f quinones depending on the con
former recognized by anenzyme during a biological trans
formation is o
f great relevance.