Decomposition of Complex Reaction Networks into Reactons

The analysis of complex reaction networks is of great importance in several chemical and biochemical fields (interstellar chemistry, prebiotic chemistry, reaction mechanism, etc). In this article, we propose to simultaneously refine and extend for general chemical reaction systems the formalism initially introduced for the description of metabolic networks. The classical approaches through the computation of the right null space leads to the decomposition of the network into complex ``cycles'' of reactions concerned with all metabolites. We show how, departing from the left null space computation, the flux analysis can be decoupled into linear fluxes and single loops, allowing a more refine qualitative analysis as a function of the antagonisms and connections among these local fluxes. This analysis is made possible by the decomposition of the molecules into elementary subunits, called "reactons" and the consequent decomposition of the whole network into simple first order unary partial reactions related with simple transfers of reactons from one molecule to another. This article explains and justifies the algorithmic steps leading to the total decomposition of the reaction network into its constitutive elementary subpart.