| Summary: | Neste trabalho realizaram-se reações de resolução enzimática de alcoóis secundários utilizando a enzima imobilizada lipase de Candida antarctica (NOVOZYME 435). Os alcoóis utilizados foram: (RS)-1-(4-metoxifenil)etanol (1a); (RS)-4-metil-2-pentanol (3a); (RS)-2-metil-3-hexanol (4a); (RS)-5-metil-2-hexanol (5a); (RS)-2-octanol (6a); (RS)-3-heptanol (7a); (RS)-6-metil-5-hepten-2-ol (8a); (RS)-1-octen-3-ol (9a). Todos os alcoóis foram resolvidos pela lipase, com exceção do álcool 4a. Nas resoluções enzimáticas os excessos enantioméricos dos álcoois e acetatos foram superiores a 98 %, havendo a conversão total (50 %) dos enantiômeros S nos respectivos acetatos: (S)-1-acetato-4-metoxifenil (1b); (S)-2-acetato-4-metil-pentano (3b); (S)-2-acetato-5-metil-hexano (5b); (S)-2-acetato-octano (6b); (S)-3-acetato-heptano (7b); (S)-2-acetato-6-metil-5-hepteno (8b); (S)-3-acetato-1-octeno (9b). Realizou-se ainda um estudo biocatalítico envolvendo reações de redução de cetonas com fungos de origem marinha. Foram utilizadas na reduções as cetonas: 4-metoxiacetofenona (1), 1-fenil-etanona (2), 4-metil-2-pentanona (3), 2-octanona (6) e a 6-metil-5-hetpen-2-ona (8) e como biocatalisadores três fungos de origem marinha (Bionectria sp Ce5, Aspergillus sydowii Ce15 e Aspergillus sydowii Ce19). A 4-metoxiacetofenona (1) foi reduzida pelos fungos Bionectria sp Ce5, Aspergillus sydowii Ce15 e Aspergillus sydowii Ce19 com excesso enantiomérico de 98% e rendimento de 65 %. A 2-octanona (6) e a 6-metil-5-hepten-2-ona (8) foram reduzidas pelo fungo A. sydowii Ce15 nos respectivos (S)-álcoois 6a e 8a com pureza enantiomérica > 98 %. Já a 1-fenil-etanona (2) foi reduzida somente pelo fungo Bionectria sp Ce5 com excesso enantiomérico de 50 % e rendimento de 25 %. A 4-metil-2-pentanona (3) não foi reduzida por nenhum dos microrganismos estudados.
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This work carried out the enzymatic reactions of alcohols by using a lipase from immobilized Candida Antarctica (NOVOZYME 435). The alcohols used were: (RS)-1- (4-methoxyphenyl) ethanol (1a), (RS)-4-methyl-2-pentanol (3a), (RS)-2-methyl-3- hexanol (4a), (RS)-5-methyl-2-hexanol (5a), (RS)-2-octanol (6a), (RS)-3-heptanol (7a), (RS)-6-methyl-5-hepten-2-ol (8a) and (RS)-1-octen-3-ol (9a). All the alcohols were catalyzed by lipase, except for the alcohol 4a. In this enzymatic resolutions the enantiomeric excesses of alcohols and acetates were more than 98% and total conversions (50%) for enantiomers of the acetates: (R)-1-acetate-4-methoxyphenyl (1b), (R)-2-acetate-4-methyl-pentane (3b), (R)-2-acetate-5-methyl-hexane (5b), (R)-2-acetateoctane (6b), (R)-3-acetate-heptane (7b), (R)-2-acetate-6-methyl-5-hepteno (8b) and (S)- 3-acetate-1-octene (9b). In addition it was studied the biocatalytic reduction of ketones with marine-derived fungi. The ketones used were the 4-metoxyacetophenone (1), 1- phenyl-etanone (2), 4-methyl-2-pentanone (3), 2-octanone (6) and 6-methyl-5-hetpen-2- one (8). The marine-derived fungi used as biocatalysts were Bionectria sp Ce5, Aspergillus sydowii Ce15 and Aspergillus sydowii Ce19. The 4-metoxyacetophenone (1) was reduced by Bionectria sp Ce5 by Aspergillus sydowii Ce15 and Aspergillus sydowii Ce19 in high enantiomeric excess (98% e.e.) and good yield, i.g., 65%. The 2- octanone (6) and 6-methyl-5-hepten-2-one (8) were reduced by A. sydowii Ce15 in the (R)-alcohols 6a and 8a in high enantiomeric purities, > 98% e.e. However the 1-phenyletanone (2) was reduced only by the fungus Bionectria sp Ce5 with enantiomeric excess of 50% and yield of 25%. The 4-methyl-2-pentanone (3) was not reduced by the microorganisms studied.
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