HYBRID EVENT: You can participate in person at Rome, Italy or Virtually from your home or work.

2nd Edition of

Chemistry World Conference

June 13-14, 2022 | Rome, Italy

Chemistry 2022

Preparative biocatalytic transformations with white rot fungi and their mechanisms

Speaker at Chemistry World Conference 2022 -  Tatyana S Zhuk
Department of Organic Chemistry, Ukraine
Title : Preparative biocatalytic transformations with white rot fungi and their mechanisms

Abstract:

The significance of biocatalytic approaches in preparative organic chemistry is intensively growing, primarily due to the high selectivity, mild reaction conditions, and environmental safeness. We focus on the enzymes produced by white-rot fungi (WRF) that represent versatile natural catalysts due to their ability to degrade the most abundant aromatic biopolymer on earth, namely lignin. Utilizing fungus D. albidofuscus and cage hydrocarbon adamantane, the potential of basidiomycetous enzymes for selective alkane C–H- functionalyzations has been desclosed. The C–H-positional selectivity (3o/2o = 3.6) and the deuterium kinetic isotopic effect (kH/kD = 2.25) values of biotransformation provide evidence for the participation of fungal metalloenzymes in the C–H-activation step. In case of toluene, phenol is the main product of biotransformation under the similar conditions. It was found that the whole sequence of the oxidation of toluene to phenol involves the formation of benzaldehyde followed by Baeyer-Villiger type rearrangement that was confirmed based on isotope labelling experiments with 18O2. During biotransformation benzaldehyde can be also partially reduced to benzylic alcohol at the early stage of fungus growing.

The reductive activity of D. albidofuscus and a number of other WRF toward aromatic and aliphatic carbonyl compounds has been screened using benzyladehyde, p-nitrobenzaldehyde, adamantanone and cyclohexanone as a model compounds. With D. albidofuscus, D. squalens, D. quercina, F. velutipes, the reductions proceed in an aqueous system with excellent selectivities to give the respective alcohols in high preparative yields. Carboxylic acids are also reduced to aldehydes and alcohols. In particular, benzoic, vanillic, ferulic, and p-coumaric acids were reduced to benzyl alcohol, vanillin, dihydroconiferyl alcohol and 3-(4-hydroxyphenyl)propan-1- ol, respectively. Thus, depending on the stage of growth, whole-cell cultures of D. albidofuscus exhibit the ability either to reduce or to oxidise organic substrates selectively at a preparative level and the reaction may be tuned by changing the age of the culture.

Biography:

Tatyana S. Zhuk has completed her PhD from Kyiv Polytechnic Institute, Ukraine and postdoctoral stay from Justus Liebig University of Giessen, Germany. With background in organic chemistry and technology Tatyana Zhuk actively works in synthetic organic chemistry, computational chemistry, surface chemistry, catalysis and publishes her results in world leading high impact journals. Currently she focuses on practical organic transformations in biocatalytic systems based on various fungi. She is interested not only in isolations of main reaction products but also in the mechanisms of biotransformations performing kinetic, isotope labeling studies, as well as isolation of pure enzymes for model experiments.

Watsapp