Reações de Biocatálise Utilizando Sistemas de Células Íntegras e de Enzimas Imobilizadas de Saccharum officinarum Linn (Cana de Açúcar)

Abstract

The present work reports the use of integral cells and immobilized enzymes of the sugar cane (Saccharum officinarum) juice as biocatalyst applied in reactions of reduction and acetylation reactions. In a first part, a set of reduction reactions was carried out using sugar cane juice (CC) as catalyst and, as substrates: acetophenone, 3-methoxyacetophenone,benzaldehyde, anisaldehyde, m-anisaldehyde, vanillin, cinnamaldehyde, -methyl-cinnamaldehyde, furfuryl, citronellal, 3-hexanone, cyclopentanone, cyclohexanone, pulegone, carvone, -keto ethyl butyrate, ethyl benzoate, ethyl butyrate, benzonitrile, benzamide, isoniazide, nitrobenzene. For several of the mentioned compounds, were obtained alcohols with excellent yields, in some cases the reactions proceded with chemoselectivity and, in other, with enantioselectivity. The second part of this work it was used immobilized enzymes of cane juice in esterification reactions of alcohols. In this sense, the alcohols: anisyc, benzylic, 3-methoxy-benzylic, cinnamyc, furfurylic, 1-phenylethan-1-ol, 3-methoxy-1-phenyl-ethan-1-ol, amylic, octylic, decanoic, citronellol, allylic, cyclopentanol, cyclohexanol, 3-hydroxy-ethyl-butyrate, -terpineol and carvacrol were tested. In the esterifications reactions were using as biocatalisador the immobilized enzymes of the cane juice (EICC), using adapted methodology of the literature. The alcohol anisyc, selected as substrate for the tests initials, in mixture with acetic anhydride and in presence of EICC it afforded an identified product as anisyl acetate. After several experiments, reactional parameters: amount of EICC, amount of substrate, time reacional, solvent, agitation speed, temperature and reuse of the enzymatic system were determined. The conditions that allowed the obtaining of the esterified derivative with better yields were: 150 mg of EICC, 200 mg substrate, 20 mL hexane, 150 rpm, 60 hours of reaction to 30°C and 24 h to 70°C. So, acetylation reactions with other alcohols were processed, being obtained good yelds. Consequently, the immobilized enzymes of Saccharum officinarum constitute a promising biocatalysts in acetylation reactions, although, other tests need to be made in the sense of optimizing the potential of the biocatalysts. The products, in the reactional mixtures were analyzed by TLC, GC-MS and 1H NMR.