Substituted Quinoline Quinones as Surrogates for the PQQ Cofactor: An Electrochemical and Computational Study

Pyrroloquinoline quinones (PQQ) are
important cofactors that shuttle
redox equivalents in diverse metalloproteins. Quinoline 7,8-quinones
have been synthesized and characterized as surrogates for PQQ to elucidate
redox energetics within metalloenzyme active sites. The quinoline
7,8-quinones were accessed using polymer-supported iodoxybenzoic acid
and the compounds evaluated using solution electrochemistry. Together
with a family of quinones, the products were evaluated computationally
and used to generate a predictive correlation between a computed ΔG and the experimental reduction potentials.