189633-88-3Relevant academic research and scientific papers
Enhanced enantioselectivity of Bacillus coagulans in the hydrolysis of 1,2-O-isopropylidene glycerol esters by thermal knock-out of undesired enzymes
Romano, Diego,Falcioni, Francesco,Mora, Diego,Molinari, Francesco,Buthe, Andreas,Ansorge-Schumacher, Marion
, p. 841 - 845 (2007/10/03)
The enantioselective hydrolysis of different (RS)-1,2-O-isopropylidene glycerol esters has been achieved with whole cells of Bacillus coagulans NCIMB 9365 furnishing the (S)-alcohol as the major enantiomer. The reaction is catalysed by a thermostable cell-bound carboxylesterase and improvement of the enantioselectivity has been achieved by heat treatment of the whole cells, which causes the knock-outs a non-enantioselective competing enzyme. Thermally-treated cells hydrolysed (RS)-1,2-O-isopropylidene glycerol esters with high enantioselectivity, the highest enantiomeric ratio (80-100) being observed for the benzoate. The biocatalyst displayed good stability and could be re-used after filtration for 12 cycles before showing significant loss of activity; repeated biotransformation batches allowed the recovery of 9.55 g/L of enantiomerically pure (S)-isopropylideneglycerol benzoate starting from 24.0 g/L of the racemic mixture.
Optimized double kinetic resolution for the preparation of (S)-solketal
Vaenttinen, Eero,Kanerva, Liisa T.
, p. 923 - 933 (2007/10/03)
The lipase AK (lipase from Pseudomonas sp.)-catalysed alcoholysis of racemic solketal (2,2-dimethyl-1,3-dioxolane-4-methanol) esters and acylation of solketal in organic solvents proceeded with E = 20-25. This enabled the preparation of the more reactive (S)-enantiomer with more than 30% total isolated yield (based on the racemate) and 95% ee by a double kinetic resolution strategy consisting of enzymatic acylation-chemical saponification-enzymatic acylation or enzymatic alcoholysis-enzymatic acylation sequences. Numerical calculations and theoretical plots for the optimal termination conversions for the 1st and 2nd resolution steps as well as for the find yields as the function of E is considered.
