Microbiological bio-reduction of prochiral carbonyl compounds by antimycotic agent Boni Protect

Effect of chemical structure of benzofuran derivatives and reaction conditions on enantioselective properties of Aureobasidium pullulans microorganism contained in Boni Protect antifungal agent

“…Compared to the unsubstituted analogue, compounds 1a , 1c , and 1e were reduced more selectively under the same conditions. 1‐(Benzofuran‐2‐yl)ethanone was transformed to the corresponding alcohol with 61% ee . However, substitution of the benzofuran ring with a 2‐phenylethyl or ethyl group in the C‐3 or C‐7 position, respectively, significantly improves the optical yields.…”

“…Compound 1d is a good substrate for each of them; therefore, the resulting enantiomeric excess is zero. Similarly, the unsubstituted analogue was reduced unselectively and with high efficiency . Probably bromomethyl ketones ideally fit into the active center of dehydrogenases with different stereopreferences, and therefore, an racemic mixture was obtained, although each of them selectively transfers the hydride ion to the prochiral side of the carbonyl bond.…”

“…In the case of 1‐(benzofuran‐2‐yl)ethanone in the presence of allyl alcohol and (9‐antryl)glyoxylate (AMA‐1), pure enantiomerically secondary alcohol was obtained. The unsubstituted bromomethyl ketone due to the addition of AMA‐1 to the reaction system was reduced with 55% optical purity . For this reason, it seemed advisable to check how potential dehydrogenase inhibitors would affect the selectivity of the bioprocess of analyzed 1‐(benzofuran‐2‐yl)ethanone derivatives.…”

“…The absolute configurations were determined by electronic circular dichroism spectra for 2a ‐ 2c and by a comparison of the optical rotation with literature data for 2d . [21, 22] The absolute configuration of 2e was assigned on the basis of a comparison of the optical rotation to the respective unsubstituted analogue …”

“…Its properties are applied not only in fruit‐growing, but also in biotechnology for production of pullulan and the fungicide aureobasidin A as well as in asymmetric organic synthesis . Previously described biotransformations show that Boni Protect containing of A. pullulans represents unusual catalytic ability to reduce unsymmetrical bulky‐bulky ketones and ketoesters . In this work, we present the universality of this microorganism in the desymmetrization reactions of other unsymmetrical prochiral compounds of sp 2 hybridization (Figure ).…”