Fungal Biotransformation: An Efficient Approach for Stereoselective Chemical Reactions

There is great interest in developing chemical technologies to achieve regioselective and stereoselective reactions since only one enantiomer is required for producing the chiral leads for drug development. These selective reactions are provided by traditional chemical synthetic methods, even under expensive catalysts and long reaction times. Filamentous fungi are efficient biocatalysts capable of catalyzing a wide variety of reactions with significant contributions to the development of clean and selective processes. Although some enzymes have already been employed in isolated forms or as crude protein extracts as catalysts for conducting selective reactions, the use of whole-cell provides advantages regarding cofactor regenerations. It is also possible to carry out conversions at chemically unreactive positions and to perform racemic resolution through microbial transformation. The current literature contains several reports on the biotransformation of different compounds by fungi, which generated chemical analogs with high selectivity, using mild and eco-friendly conditions. Prompted by the enormous pharmacological interest in the development of stereoselective chemical technologies, this review covers the biotransformations catalyzed by fungi that yielded chiral products with enantiomeric excesses published over the period 2010-2020. This work highlights new approaches for the achievement of a variety of bioactive chiral building blocks, which can be a good starting point for the synthesis of new compounds combining biotransformation and synthetic organic chemistry.