O uso de hidrogênio molecular pode reduzir a citotoxicidade do radical hidroxil em meio aquoso? Investigação combinada de dinâmica molecular e teoria do estado de transição

Abstract

The huge presence of free radicals in our body can trigger diseases of various forms. Molecular hydrogen has a specificity in its reactional performance, and the hydroxyl radicals are preferably reduced by it. Studies on the use of molecular hydrogen with the application on the medical area have become increasingly popular. The use of the gas composed by the simplest known atoms created interest of researchers in the use of this gas, being already verified the effectiveness of the treatment in several types of diseases. Thus, through this work, molecular dynamics, ab initio methods and Transition State Theory (TST) were used combined to evaluate the behavior of the reaction between molecular hydrogen (H2) and hydroxyl radicals (OH·) in an aqueous system and in the gas phase. The presence of the aqueous system together with the temperature is necessary to create a possibility of an analysis similar to the human body. We used quantum dynamics for reaction investigation due to the tunneling effect present in the reaction and some correction methods for characterization of the reaction rate, such as d-TST and Bell-58. We observed in all methods of analysis the direct influence of the aqueous system on the increase of reaction speed even on deep tunneling effect by the Arrhenius plot. We hope that with the results of this project we can contribute with the medical community and the social community in general to the improvement of a possible method of treatment of diseases in the future.