Four commercial lipase preparations immobilized by covalent attachment on epoxy-polysiloxane-β-cyclodextrin were tested as potential biocatalysts to mediate the esterification reaction of isopentanol with caprylic acid in solvent-free medium. Among them, the immobilized lipase from Rhizopus oryzae was the most active biocatalyst, attained ester conversion higher than 80% in 24 h, being selected for subsequent tests using fusel oil as source of isopentanol. An experimental design was performed and the analysis of the results revealed that the formation of the isopentyl caprylate was strongly influenced by the variable molar ratio at 95% of confidence level. The proposed mathematical model allowed predicting that the excess of caprylic acid (molar ratio fusel oil to acid of 1:1.5) and reaction temperature of 45 ºC favor the reaction to attain high ester conversion. Sensory evaluation of the flavors profile in relation to all the components involved in the reaction (caprylic acid, fusel oil and esters) showed that the formed esters had distinct aromas from the starting materials, confirming that the changes in flavors occurred before and after esterification reactions.

ABSTRACT Cardanol is a constituent of Cashew Nut Shell Liquid that presents larvicidal activity against Aedes aegypti. The isolation of cardanol is somewhat troublesome, however, in this work we describe an efficient and inexpensive method to obtain it as a pure material. The compound was used as starting material to make chemical transformation leading to saturated cardanol, epoxides and, halohydrins. These derivatives were tested for toxicity against Aedes aegypti larvae. The results showed that iodohydrins are very promising compounds for making commercial products to combat the vector mosquito larvae presenting a LC50 of 0.0023 ppm after 72 h of exposure.

Several alkyl esters were synthesized, purified, characterized by ¹H NMR and employed as standards for establishing chromatographic methods to monitor their formation in the synthesis of biodiesel. The efficiency of the chromatographic methods was confirmed with the products of enzymatic transesterification of babassu oil with different alcohols (C2 to C4), using Lipozyme as catalyst.