RESUMO
The lipase B from Candida antarctica (Novozym 435®, CALB) efficiently catalyzed the kinetic resolution of some aliphatic secondary alcohols: (±)-4-methylpentan-2-ol, (±)-5-methylhexan-2-ol, (±)-octan-2-ol, (±)-heptan-3-ol and (±)-oct-1-en-3-ol. The lipase showed excellent enantioselectivities in the transesterifications of racemic aliphatic secondary alcohols producing the enantiopure alcohols (>99% ee) and acetates (>99% ee) with good yields. Kinetic resolution of rac-alcohols was successfully achieved with CALB lipase using simple conditions, vinyl acetate as acylating agent, and hexane as non-polar solvent.
Assuntos
Acetatos/isolamento & purificação , Álcoois Graxos/isolamento & purificação , Proteínas Fúngicas/química , Lipase/química , Acetatos/química , Biocatálise , Candida/enzimologia , Esterificação , Álcoois Graxos/química , Hexanos/química , Solventes/química , Estereoisomerismo , Especificidade por Substrato , Compostos de Vinila/químicaRESUMO
The asymmetric reduction of 2-chloro-1-phenylethanone (1) by seven strains of marine fungi was evaluated and afforded (S)-(-)-2-chloro-1-phenylethanol with, in the best case, an enantiomeric excess of 50% and an isolated yield of 60%. The ability of marine fungi to catalyse the reduction was directly dependent on growth in artificial sea water-based medium containing a high concentration of Cl(-) (1.2 M). When fungi were grown in the absence of artificial sea water, no reduction of 1 by whole cells was observed. The biocatalytic reduction of 1 was more efficient at neutral rather than acidic pH values and in the absence of glucose as co-substrate.
Assuntos
Fungos/metabolismo , Água do Mar/microbiologia , ômega-Cloroacetofenona/metabolismo , Biotransformação , Meios de Cultura/química , Fungos/isolamento & purificação , OxirreduçãoRESUMO
Nine strains of marine-derived fungi (Aspergillus sydowii Ce15, A. sydowii Ce19, Aspergillus sclerotiorum CBMAI 849, Bionectria sp. Ce5, Beauveria felina CBMAI 738, Cladosporium cladosporioides CBMAI 857, Mucor racemosus CBMAI 847, Penicillium citrinum CBMAI 1186, and Penicillium miczynskii Gc5) were screened, catalyzing the asymmetric bioreduction of 1-(4-methoxyphenyl)ethanone 1 to its corresponding 1-(4-methoxyphenyl)ethanol 2. A. sydowii Ce15 and Bionectria sp. Ce5 produced the enantiopure (R)-alcohol 2 (>99% ee) in accordance with the anti-Prelog rule and, the fungi B. felina CBMAI 738 (>99% ee) and P. citrinum CBMAI 1186 (69% ee) in accordance with the Prelog rule. Stereoselective bioreduction by whole cells of marine-derived fungi described by us is important for the production of new reductases from marine-derived fungi.