A síntese da 4,6-dimetil-3-ciano-2-piridona foi estudada na reação catalisada pela lipase de Candida rugosa. A metodologia de superfície de resposta (MSR) foi aplicada para a otimização das condições experimentais. O estudo mostrou que a temperatura e a razão molar cianoacetamida/acetilacetona têm grande influência sobre o rendimento da reação. O rendimento máximo foi obtido a 44 ºC e razão molar cianoacetamida/acetilacetona igual a 36. A cinética da síntese enzimática da 4,6-dimetil-3-ciano-2-piridona foi investigada, e foi determinado que o mecanismo ping-pong bi-ter com inibição da cianoacetamida é coerente com os resultados obtidos. O mecanismo da reação catalisada pela Lipase foi proposto

The synthesis of 4,6-dimethyl-3-cyano-2-pyridone was studied in a reaction catalyzed with Candida rugosa lipase. A response surface methodology (RSM) was applied for the optimization of the experimental conditions. The study showed that temperature and molar ratio cyanoacetamide/acetylacetone have a great influence on the yield of the reaction; the maximum yield was achieved at 44 ºC with a molar ratio cyanoacetamide/acetylacetone of 36. The kinetics of the enzymatic synthesis of 4,6-dimethyl-3-cyano-2-pyridone was investigated, and it was determined that a ping-pong bi-ter mechanism with cyanoacetamide inhibition fits the obtained results. The mechanism of lipase-catalyzed reaction was proposed.

Lipase from Candida rugosa was covalently immobilized on Sepabeads EC-EP for application for amyl caprylate synthesis in an organic solvent system. Several solvents were tested in terms of biocatalyst stability and the best result was obtained with isooctane. The lipase-catalyzed esterification in the selected system was performed in batch and fluidized bed reactor systems. The influence of several important reaction parameters including temperature, initial water content, enzyme loading, acid/alcohol molar ratio, and time of addition of molecular sieves is carefully analyzed by means of an experimental design. Almost complete conversion (> 99%) of the substrate to ester could be performed in a batch reactor system, using lipase loading as low as 37 mg g-1 dry support and in a relatively short time (24 hrs) at 37�C, when high initial substrate molar ratio of 2.2 is used. Kinetics in a fluidized bed reactor system seems to still have a slightly better profile than in the batch system (90.2% yields after 14 hrs). The fluidized bed reactor operated for up 70 hrs almost with no loss in productivity, implying that the proposed process and the immobilized system could provide a promising approach for the amyl caprylate synthesis at the industrial scale.