Modelling of the statin intermediate synthesis catalyzed by 2-deoxyribose-5-phosphate aldolase

Statini su heterogena skupina lijekova koji se primjenjuju u prevenciji i liječenju bolesti kardiovaskularnog sustava. U radu je provedena sinteza (3R,5R)-6-kloro-3,5-dihidroksi heksanala (laktona), važnog prekursora u dobivanju statina. Sinteza je provedena u reakciji aldolne kondenzacije kloroacetaldehida i acetaldehida katalizirane enzimom 2-deoksiriboza-5-fosfat aldolazom (DERA). Ispitana je stabilnost i aktivnost enzima DERA-e pri različitim temperaturama i puferima pri različitim pH vrijednostima. Kao optimalni uvjeti za provedbu reakcije aldolne kondenzacije katalizirane enzimom DERA pokazali su se temperatura od 25°C i 0,1 M TEA-HCl pufer pH 7. Ispitana je deaktivacija enzima u prisutnosti različitih koncentracija acetaldehida i kloroacetaldehida te je opisana kinetikom drugog reda. Utvrđeno je da konstanta deaktivacije eksponencijalno raste s koncentracijom acetaldehida i kloroacetaldehida prisutnih u sustavu. Enzim je kinetički karakteriziran te je kinetika opisana dvosupstratnom Michaelis-Menteničinom jednadžbom. Postavljen je matematički model sinteze laktona te je provedena ocjena valjanosti u kotlastom reaktoru, ponovljivom kotlastom reaktoru te kotlastom reaktoru s dotokom.Statins are a heterogeneous group of medications used in prevention and treatment of cardiovascular diseases. In this study the synthesis of an important precursor of statin, (3R, 5R)-6-chloro-3,5-dihydroxyhexanal (lactone) was carried out. The synthesis was performed in the reaction of aldol condensation of chloroacetaldehyde and acetaldehyde catalyzed by the enzyme 2-deoxyribose-5-phosphate aldolase (DERA-e). In order to find optimal conditions for lactone synthesis in the reaction of aldol condensation, stability and activity of the enzyme were tested at different temperatures and in different buffer solutions at different pH values. The optimal conditions were found to be: 25°C and 0,1 M TEA-HCl buffer pH 7. Enzyme deactivation in a presence of different concentrations of acetaldehyde and chloroacetaldehyde was investigated. Deactivation was described with a second-order kinetic model. It was observed that a deactivation constant increases exponentially with the concentration of acetaldehyde and chloroacetaldehyde. The enzyme was kinetically characterized and kinetics was described by two-substrate Michaelis-Menten equation. Mathematical model of lactone synthesis was proposed and was validated in a batch, repetitive batch and fed-batch reactor