Reactive Molecular Dynamics Simulation On Degradation Of Mycotoxins By Reactive Oxygen Species In Cold Atmospheric Plasma

With the in-depth implementation of major food safety strategies and the increasing demands of people’s lives,the problem of mycotoxin contamination has attracted widespread attention.As toxic metabolites of fungal species,mycotoxins are widely present in cereals,fruits,and related products,posing a great threat to human health and industrial economy.Cold atmospheric plasma(CAP),as a non-thermal treatment technology,brings new ideas and methods to solve the problem of mycotoxin contamination.Frequent particle collisions in plasma can generate abundant reactive species,and numerous reactive species play a key role in the process of interaction with organic molecules,presenting the advantages of high efficiency,environmental protection,and non-selectivity.Current studies have clarified that CAP can play an effective role in degrading a variety of mycotoxins,but the potential mechanism of interaction between CAP reactive species and mycotoxins is still unclear,which limits the development and industrial application of CAP technology in this field.The reactive species that plays a key role in CAP treatment of mycotoxins is reactive oxygen species(ROS),so the interaction of ROS with common mycotoxins was chosen as the object of study,and reactive molecular dynamics(RMD)simulation was employed to investigate the mechanism of interaction between ROS and key toxic sites at the atomic scale.Based on this,the effect of different concentrations of ROS on the degradation effect of mycotoxins was further analyzed to provide mechanistic support and regulatory guidelines for the degradation of mycotoxins and even other organic pollutants by CAP.The main content of this paper includes the following aspects:(1)The basic concepts of cold atmospheric plasma,its active ingredients,and applications in various fields are outlined,with emphasis on the advantages of mycotoxins degradation by plasma and the current status of research.The basic principles of reactive molecular dynamics simulation and ReaxFF force field are introduced,and the flow and relevant parameter settings of the research method in this paper are explained in detail.(2)The interaction mechanisms of four reactive oxygen species(oxygen atom,hydroxyl radical,hydrogen peroxide,and ozone)with deoxynivalenol(DON)and aflatoxin B1(AFB1)molecules were investigated in simulations.The simulation results showed that the reactive oxygen species could cause the destruction of key toxicity sites through the processes of the addition reaction of double C=C bond,the ring-opening reaction of lactone ring and epoxide ring,etc.The comparison with the experimental results effectively validates the simulation results.The degradation patterns of the double C=C bond at the shared toxicity sites of AFB1 and DON were further analyzed.In addition to the addition reaction,the double C=C bond was also reduced by the hydrogen atom abstraction reaction or bond breaking at other sites.(3)The degradation pathways and degradation products of the lactone ring-containing mycotoxins upon the impact of ROS were studied,and the reaction types of primary toxicity sites were summarized.AFB1,zearalenone,ochratoxin B,and patulin are common lactone ringcontaining mycotoxins.The simulation results revealed that the degradation processes of the lactone ring mainly include ring-opening reaction and reduction of lactone carbonyl groups,with ozone playing an important role in the ring-opening reaction of lactone rings and hydrogen peroxide causing the reduction of lactone carbonyl groups due to the loss of its hydrogen atoms.Different mycotoxins also have several different sites,and the types of degradation reactions at the major toxicity sites include addition reaction,oxidation reaction,reduction reaction,ringopening reaction,side chain shedding,and even skeletal structure breakage.