Biorredução de derivados de chalconas por fungos de ambientes amazônicos

Abstract

Chalcones are known to exhibit diverse biological potential. However, their chemical modification is still limited under extreme conditions, or with reagents that are considered potential environmental contaminants, or are difficult to obtain. In this sense, the search for less environmentally damaging and more efficient processes has been gaining ground in the literature, such as biocatalyzed reactions by fungi, which consist of using enzymes or cofactors as biological catalysts in organic reactions. Knowing this, and in order to explore the biotechnological potential of filamentous fungi not yet explored in these biocatalytic processes, this work aimed to investigate the C=C bond-reducing potential of chalcones using filamentous fungi isolated from Amazonian soil, such as Aspergillus niger CBMAI 2756 and Talaromyces verreculosus CBMAI 2754. To this end, 11 chalcones were synthesized, catalyzed by sodium hydroxide (1.25 M) following the aldol condensation reaction protocol, at room temperature, for 6 h of stirring. All products obtained were solids and characterized by melting point and gas chromatography-mass spectrometry (GC-MS). Subsequently, the compounds were subjected to a biotransformation reaction containing 5 g of moist mycelium (previously fermented) and chalcones (50 mg) solubilized in DMSO in a buffered medium at pH 7. The reaction was stirred (130 rpm) for 7 days. It was then completed by liquid-liquid extraction, and the excess solvent was removed by rotary evaporation. The reaction output was characterized by GC-MS. In all products formed, a reduction of the C=C double bond was observed, demonstrating the efficiency of the selective reduction potential of both fungi. At the end of this investigation, it was concluded through GC-MS analyses that both microorganisms possess favorable enzymatic capacity in the process of reducing the C=C bond, characteristic of ene-reductase type enzymes. However, Talaromyces verreculosis CBMAI 2754 showed a slight increase in reducing capacity, thus evidencing a better biotechnological potential.