2016 Conference on Computational Modelling with COPASI
Manchester Institute of Biotechnology, 12th – 13th May, 2016
1 - University of Castilla-La Mancha, Spain
Keywords: COPASI, tyrosinase, o-diphenolic compounds, simulated progress curves, nonlinear set of differential equations
Catechol derivatives are present in numerous natural products and synthetic compounds used in various sectors of the chemical industry such as food, cosmetic, pharmaceutical and polymer industries. The antioxidant activity usually conferred to these compounds is the property on which their application is often based. Although several chemical methods are available to chemists to produce catechols, the enzymatic ortho-hydroxylation using tyrosinase in the presence of an excess of a reducing agent, such as ascorbic acid or NADH, and molecular oxygen constitutes one of the most practical approaches as long as the ortho-selectivity of the process can be controlled, in a nonpolluting way. Examples of o-diphenolic compounds that can be thus synthesized include oleuropein, hydroxytyrosol, 3,4-dihydroxyphenylacetic acid, L-DOPA and 3'-hydroxyacetaminophen. In the present communication, a mathematical model of the system is proposed, based on the internal catalytic action mechanism of tyrosinase. Simulated progress curves of the biocatalytic reaction were obtained by numerical solution of the nonlinear set of differential equations (9 eqs) corresponding to the model proposed by using COPASI. This model is valid for simulating the kinetic behavior of the tyrosinase-mediated synthesis of any o-diphenol from its corresponding monophenol in the presence of a reducing agent, the only modification necessary being the numerical values of the rate constants. Therefore, the present model can be helpful for implementation of the biocatalytic process for industrial purposes, permitting the process to be controlled.