Comparative Study of Sulphur Derivatives to Reduce Oxidative Stress and Oral Inflammation Through Stereochemical Analysis and DFT Calculations

Reactive oxygen species (ROS), including superoxide (O₂˙−), hydroxyl (OH˙), and hydrogen peroxide (H₂O₂) radicals, play important roles in many biological processes. However, they cause oxidative stress that underlies oral inflammation when present in excessive amounts. Antioxidants tend to reversibly inactivate ROS through electron transfer (donation) or non-covalent stabilization (sequestration) of radicals. Many flavonoids, such as phenolic acids abundant in vegetables and beverages, have been recognized as ROS scavengers. Furthermore, molecules containing sulfur offer another approach to improving on flavonoids and other polyphenols. Sulfur-based molecules provide diverse physicochemical properties, including electron richness, the ability to participate in multiple covalent bonds, and unique stereochemistry. These molecules act as both electron donors and acceptors and exhibit distinct physical and chemical properties arising from their high atomic numbers.

Antioxidant efficiency of sulfur compounds is compared with that of relevant flavonoids and other reference compounds. For the studied compounds, a stereochemical analysis is complemented by quantum-chemical density functional theory (DFT) calculations of their electronic properties.

This study uses a few determinants in predicting how radicals will be stabilized and regenerated to reduce oral diseases. We investigate how certain sulfur-containing molecules, referred to here as ‘sulfur antioxidants,' are more effective at treating diseases than analogous phenolic antioxidants. Predictions and comparisons are made to identify more stable and reactive molecules than conventional antioxidants currently in use.