Computational Quantum Study of Intermediates Formed During the Partial Oxidation of Melatonin

• Main Author: Oladiran, Oladun
• Format: Others
• Language: English
• Published: Digital Commons @ East Tennessee State University 2020
• Subjects: Melatonin; Spin traps; Free Radicals; DFT; HF; Basis Set Extrapolation; Chemistry; Physical Chemistry
• Online Access: https://dc.etsu.edu/etd/3745; https://dc.etsu.edu/cgi/viewcontent.cgi?article=5235&context=etd

Melatonin is a neurohormone produced by the pineal gland in the brain. It functions as an antioxidant to scavenge free radicals. Free radicals are reactive species; they often oxidize the cells leading to oxidative stress which may lead to severe health complications. Reaction of melatonin with free radicals is known to be stepwise, as such the stability of the intermediates can be examined. Thus, the possibility of using melatonin as an in vivo spin trap can be determined. Spin traps allow characterization of unstable radical species using electron spin resonance spectroscopy. In this research, ab initio quantum chemistry techniques were used to calculate the energies of selected intermediates formed during the partial oxidation of melatonin by hydroxyl radical. Specifically, optimized geometries for melatonin, and selected intermediates with ·OH were obtained at the DFT/B3LYP/cc-pVXZ and HF/cc-pVXZ (X = D, T, Q) levels of theory. Extrapolations to the complete basis set limit were also performed.