AUTHOR=Parise Angela , De Simone Bruna Clara , Marino Tiziana , Toscano Marirosa , Russo Nino 

TITLE=Quantum Mechanical Predictions of the Antioxidant Capability of Moracin C Isomers

JOURNAL=Frontiers in Chemistry

VOLUME=9

YEAR=2021

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2021.666647

DOI=10.3389/fchem.2021.666647

ISSN=2296-2646

ABSTRACT=<p>The antioxidant capability of moracin C and <italic>iso</italic>-moracin C isomers against the OOH free radical was studied by applying density functional theory (DFT) and choosing the M05-2X exchange-correlation functional coupled with the all electron basis set, 6-311++G(d,p), for computations. Different reaction mechanisms [hydrogen atom transfer (HAT), single electron transfer (SET), and radical adduct formation (RAF)] were taken into account when considering water- and lipid-like environments. Rate constants were obtained by applying the conventional transition state theory (TST). The results show that, in water, scavenging activity mainly occurs through a radical addition mechanism for both isomers, while, in the lipid-like environment, the radical addition process is favored for <italic>iso</italic>-moracin C, while, redox- and non-redox-type reactions can equally occur for moracin C. The values of pKa relative to the deprotonation paths at physiological pH were predicted in aqueous solution.</p>