The use of biocatalysts in organic chemistry for catalyzing chemo-, regio- and stereoselective transformations has become an usual tool in the last years, both at lab and industrial scale. This is not only because of their exquisite precision, but also due to the inherent increase in the process sustainability. Nevertheless, most of the interesting industrial reactions involve water-insoluble substrates, so the use of (generally not green) organic solvents is generally required. Although lipases are capable of maintaining their catalytic precision working in those solvents, reactions are usually very slow and consequently not very appropriate for industrial purposes. Increasing reaction temperature would accelerate the reaction rate, but this should require the use of lipases from thermophiles, which tend to be more enantioselective at lower temperatures, as they are more rigid than those from mesophiles. Therefore, the ideal scenario would require a thermophilic lipase capable of retaining high enantioselectivity at high temperatures. In this paper, we describe the use of lipase from Geobacillus thermocatenolatus as catalyst in the ethanolysis of racemic 2-(butyryloxy)-2-phenylacetic to furnish both enantiomers of mandelic acid, an useful intermediate in the synthesis of many drugs and active products. The catalytic performance at high temperature in a conventional organic solvent (isooctane) and four imidazolium-based ionic liquids was assessed. The best results were obtained using 1-ethyl-3-methyl imidazolium tetrafluoroborate (EMIMBF4) and 1-ethyl-3-methyl imidazolium hexafluorophosphate (EMIMPF6) at temperatures as high as 120 °C, observing in both cases very fast and enantioselective kinetic resolutions, respectively leading exclusively to the (S) or to the (R)-enantiomer of mandelic acid, depending on the anion component of the ionic liquid.

Pseudomonas fluorescens Pf1TZ was inhibitory in vitro to a number of phytopathogenic fungi and could protect vine plantlets against Botrytis cinerea. Total protection was reached after 3 weeks of bacterial inoculation. The endophytism of Pf1TZ was confirmed by confocal microscopy using its inherent fluorescence. The molecular characterization of Pf1TZ indicated the presence of genes from clusters encoding pyoluteorin and phenazine. The chromatographic purification and LC-MS(n) analysis revealed that the most active one has a molecular mass of 504 Da.

Keywords: Geobacillus thermocatenolatus; lipases; ethanolysis; ionic liquids; kinetic resolution; mandelic acid.

In this paper, we describe the effectiveness of the combination between an organic solvent system mixture with orthoformates with different chain sizes from one to four carbon atoms. These orthoesters have been used as a “water trapper/alcohol releaser molecule” to reach a notable improvement in enantioselectivity and enantiomeric excess of our target compound, (S)-2-(4-isobutylphenyl)propanoic acid (ibuprofen eutomer), during the enzymatic kinetic resolution of rac-ibuprofen using immobilized lipase B of Candida antarctica as a biocatalyst. At the same time, one of the great problems of biocatalysis in organic media has been solved by eliminating excess water in the medium that allows the reversibility of the reaction. Following the optimization of the reaction conditions, an increase in enantiomeric excess and enantioselectivity was reached by using these acyl donors in the presence of a cosolvent.