Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas, Programa de Pós-Graduação em Química, Florianópolis, 2012 / Made available in DSpace on 2013-06-25T19:55:42Z (GMT). No. of bitstreams: 1
314164.pdf: 3161010 bytes, checksum: 205e23028968071ac13bb22a65278f4e (MD5) / Neste trabalho, a lipase comercial de Burkholderia cepacia (LBC) foi imobilizada nas blendas de amido/PEO e proteína de soja/PEO, na presença ou ausência de B-ciclodextrina (B-CD). Estes sistemas foram usados como catalisadores na acilação do 3-nitro-1-feniletanol [(R,S)-15b] e do 3,4-metilenodioxi-1-feniletanol [(R,S)-16b] com diferentes doadores acilas (acetato de vinila, acetato de etila, acetato de isopropenila, propionato de vinila, laurato de vinila e estearato de vinila), na presença de t-butil metil éter (MTBE). Foram avaliadas a variação molar do álcoois em relação ao acetato de vinila, uso da LBC não imobilizada ou suportada em diversos filmes, efeito da temperatura e a reação na ausência da LBC. Todas as reações utilizando a LBC, apresentaram excelente excesso enantioméricos dos produtos (eep >99%) e razão enantiomérica (E >200), no estudo da razão molar alcool: acetato de vinila. Acima da razão molar 1:2, as conversões foram similares, sendo de 31-50% para o (R)-éster 15c e de 45-50% para o (R)-éster 16c. Ao utilizar a LBC imobilizada em diversos filmes, as conversões em (R)-éster 15c e 16c foram dependentes dos suportes. Foram obtidas conversões baixas (2-14%) com a LBC imobilizada em filmes de amido e carboximetil celulose (CMC). Os melhores resultados foram obtidos com a LBC imobilizada nos filmes de amido/PEO e proteína de soja/PEO, sendo de 28-50%. Na presença de B-CD, as conversões foram de 32-50%. Na ausência da lipase, não foi observada a formação dos produtos, independente do suporte usado. Porém, ao usar as blendas de proteína de soja/PEO, as conversões foram de 3%. Para as reações com a LBC na forma livre, as conversões aos (R)-éster 15c e (R)-éster 16c foram de 4% e 18%, em 48h. Ao usar as temperaturas de 25º, 35º e 45º C, as conversões aos produtos variaram de 16-40%, 28-50% e 26-41% para o (R)-éster 15c e de 27-40%, 37-50% e 33-44% para o (R)-éster 16c, respectivamente. As lipases de Burkholderia cepacia (LPS-SD), de Mucor Javanicus (LMJ 10), de Pseudomonas fluorescens (LAK 20), de Aspergillus niger (LAN 12), de Candida cylindracea (LAY 30) e de Thermomyces lanuginosus (LTL-IM), foram imobilizadas nos filmes de amido/PEO (1/1 m/m) e proteína de soja/PEO (1/1 m/m), com ou sem B-CD. Estes sistemas, foram usados na reação de transesterificação do acetato de vinila com (R,S)-15b. Ao usar as lipases LAY 30, LMJ 10 e LAN 12, as conversões foram de 0-20%, com eep de 65-86%. Ao usar as lipases LPS-SD, LAK 20 e LTL-IM, todos os eep foram >99%, e maior conversão foi obtida com o sistema LPS-SD/proteína de soja/PEO/B-CD (40%).
Avaliou-se o efeito do solvente orgânico na reação do acetato de vinila com (R,S)-15b, catalisada pela LBC suportada nas blendas citadas no estudo anterior. Com o uso do t-butanol, ciclohexano, éter di-isopropílico e acetona, as conversões foram de moderadas a boas (19-50%). Na presença de THF, as conversões foram de 2-10%. Não foi observada relação direta com os valores de log P dos solventes. Os álcoois racêmicos 3-nitro-1-feniletanol (15b), 3,4-metilenodioxi-1-feniletanol (16b), 4-nitro-1-feniletanol (17b), 4-metil-1-feniletanol (18b), 4-bromo-1-feniletanol (19b) e o 4-métoxi-1-feniletanol (20b) foram usados em reações com acetato de vinila. Como catalisador foi utilizado a LBC imobilizada em filmes de amido/PEO (1/1 m/m) e proteína de soja/PEO (1/1 m/m), na presença ou ausência de B-CD. As conversões aos produtos foram maiores na presença de grupos doadores de elétrons. Em 24h, as conversões ao (R)- éster 17c (4-nitro) foram de 17-29% e do (R)- éster 16c (3,4-metilenodioxi) variaram de 37-45%. A LBC, imobilizada em quatro (4) suportes diferentes, foi reutilizada após 30 e 90 dias de estocagem a temperatura ambiente em n-hexano, na reação do acetato de vinila com (R,S)-15b em MTBE. Após 30 dias, as conversões ao (R)-éster 15c variaram de 20-43%, e após 90 dias de 11-27%. Concluindo, os resultados obtidos mostraram que as blendas de amido/PEO (1/1 m/m) e proteína de soja/PEO (1/1 m/m) com ou sem B-CD puderam ser usadas como suportes para diferentes lipases. Esses sistemas foram também usados, com sucesso, na resolução de vários álcoois racêmicos derivados do 1-feniletanol sob condições brandas de reação, e puderam ser reutilizados. <br> / Abstract : In this study, commercial lipase obtained from Burkholderia cepacia (LBC) was immobilized in starch/PEO and soybean protein/PEO blends, in the presence or absence of B-cyclodextrin (B-CD). These systems were used as biocatalyst in the acylation of 3-nitro-1-phenylethanol [(R,S)-15b] and 3,4-methylenedioxy-1-phenylethanol [(R,S)-16b] with various acyl donors (vinyl acetate, ethyl acetate, isopropenyl acetate, vinyl propionate, vinyl laurate and vinyl stearate) in the presence of methyl tert-butyl ether (MTBE). The influence of the alcohol:vinyl acetate molar ratio, the use of LBC, free or immobilized in different films (or blends) and the effect of temperature were studied. The reaction was also carried out in the absence of LBC. In the studies on the alcohol: vinyl acetate molar ratio are used the LBC, in all reactions the enantiomeric excess of products (eep>99%) and the enantiomeric ratio were excellent (E >200). The values for the conversion to products were dependent on this parameter. Using a molar ratio of 1:2 or higher, the conversion degrees were similar, these being 31-50% for (R)-ester 15c and 45-50% to (R)-ester 15c. When LBC immobilized in various films was used the conversion degrees to (R)-esters 15c and 16c were dependent on the support. With the use of starch or carboxymethyl cellulose (CMC) as the support the conversions were low (2-14%). Best results were achieved when LBC was immobilized in Starch/PEO or soybean protein/PEO films, these being of 28-50%. With the presence of B-CD in the films, the conversions were 32-50%. In the absence of lipase, no product was detected regardless of the support used. However, when the soybean protein/PEO blends were used, the conversion was 3%. Using free LBC, the conversion degrees to (R)-esters 15c and 16c in 48h were 4% and 18%, respectively. With the application of temperatures of 25º, 35º and 45º C the conversion degrees were 16-40%, 28-50% and 26-41% for (R)-ester 15c and 27-40%, 37-50% and 33-44% for (R)-ester 16c, respectively. The lipases obtained from Burkholderia cepacia (LPS-SD), Mucor Javanicus (LMJ 10), Pseudomonas fluorescens (LAK 20), Aspergillus niger (LAN 12), Candida cylindracea (LAY 30) and Thermomyces lanuginosus (LTL-IM) were immobilized in starch/PEO(1/1 m/m) and soybean protein/PEO (1/1 m/m) blends in the presence or absence of B-CD. These systems were then used in the transesterification reaction of vinyl acetate with (R,S)-15b. Using LAY 30, LMJ 10 and LAN 12 lipases the conversion degrees were 0-20%, with an eep of 65-86%. With the use of LPS-SD, LAK 20 and LTL-IM lipases the eep was >99%, and the highest conversion (40%) was obtained using the soybean protein/PEO/B-CD. The solvent effect was evaluated in the reaction of vinyl acetate with (R,S)-15b, catalyzed by LBC immobilized in the blends used in the previous study. With the use of t-butanol, cyclohexane, di-isopropyl ether and acetone the conversion degrees were moderate or good (19-50%). In the presence of THF the conversion degrees were 2-10%. No direct relation with the solvent log P values was observed. The racemic alcohols 3-nitro-1-phenylethanol (15b), 3,4-methylenedioxy -1- phenylethanol (16b), 4-nitro-1-phenylethanol (17b), 4-methyl-1-phenylethanol (18b), 4-bromo-1-phenylethanol (19b) and 4-methoxy-1-phenylethanol (20b) were used in the transesterification reaction of vinyl acetate with (R,S)-15b. LBC was immobilized in starch/PEO (1/1 m/m) and soybean protein/PEO (1/1 m/m) blends, in the presence or absence of B-CD. The conversion degrees into products were higher in the presence of electron donor groups. In 24 h the degrees of conversion to (R)-ester 17c were 17-29% and to R-ester 16c were 37-45%. LBC immobilized in four different supports was reused after 30 and 90 days of storage at room temperature in n-hexane, in the reaction of vinyl acetate with (R,S)-15b in MTBE. The conversion degrees for (R)-ester 15c were 20-43% after 30 days of storage and 11-27% after 90 days of storage. In conclusion, the results obtained show that the starch/PEO (1/1 m/m) and soybean protein/PEO (1/1 m/m) blends, in the presence or absence of B-cyclodextrin, can be used as supports for various lipases. These systems were also used successfully in the resolution of racemic alcohols derived from 1-phenylethanol, under mild reaction conditions, and the possibility of their reused was verified.
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufsc.br:123456789/100516 |
| Date | January 2012 |
| Creators | Ledra, Carlos Geovanni Alves |
| Contributors | Universidade Federal de Santa Catarina, Nascimento, Maria da Graça |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | 115 p.| il., grafs., tabs. |
| Source | reponame:Repositório Institucional da UFSC, instname:Universidade Federal de Santa Catarina, instacron:UFSC |
| Rights | info:eu-repo/semantics/openAccess |
Page generated in 0.0021 seconds