Enantio convergent biotransformation of O,O-dimethyl-4-oxoazetidin-2-ylphosphonate using fungal cells of Penicillium minioluteum and purified enzymes.

This report presents the bioconversion of O,O-dimethyl-4-oxoazetidin-2-ylphosphonate 1 performed in two ways: with the enzymatic system of P. minioluteum and with the application of purified enzymes: penicillinase and two proteases of different origin. Recorded NMR spectra allowed confirming the reaction progress and also postulating possible mechanism of conversion. The path of bioconversion was defined as enantio convergent process for both modes of applied biocatalysts. This means that kinetically driven resolution of racemic mixture of the substrate leads to the one enantiomer of the product. The bioconversion started from ester bond hydrolysis (equally in both enantiomers) with the conversion degree from 30% (whole-cell) to 35% (isolated enzymes) and with the production of optically pure monoester (compound 2; 100% of e.e). For whole-cell bioprocess it was the initiative step for the enantioselective amide bond hydrolysis, what resulted in synthesis of desired product 3-amino-3-phosphonopropanoic acid 4. However, the most effective enzymatic hydrolysis of ester bond performed with penicillinase from Enterobacter cloacae led only to the monoester product 2.

Chiral phosphinate degradation by the fusarium species: scope and limitation of the process.

Biodegradable capacities of fungal strains of Fusarium oxysporum (DSMZ 2018) and Fusarium culmorum (DSMZ 1094) were tested towards racemic mixture of chiral 2-hydroxy-2-(ethoxyphenylphosphinyl) acetic acid-a compound with two stereogenic centres. The effectiveness of decomposition was dependent on external factors such as temperature and time of the process. Optimal conditions of complete mineralization were established. Both Fusarium species were able to biodegrade every isomer of tested compound at 30°C, but F. culmorum required 10 days and F. oxysporum 11 days to accomplish the process, which was continuously monitored using the (31)P NMR technique.