Biocatalytic dealkylation toolbox for organic synthesis

Complex multistep organic syntheses often require the use of protecting groups to temporarily hide certain parts of the molecule, such as an otherwise reactive alcohol function, from chemical transformations. Methyl ethers and related alkyl derivatives meet almost all of the criteria for a perfect alcohol protecting group, as they are easy to introduce, cheap, and chemically robust. This last point is also its greatest weakness since the cleavage requires very harsh chemical conditions, which severely limits compatibility with complex molecules. This multidisciplinary project set out to tackle this problem, bridging expertise from organic chemistry, biocatalysis, and molecular biology, hosted at TU Wien and the University of Greifswald, respectively. Work is underway to establish a biocatalytic method using redox-active enzymes from the cytochrome P450 family to catalyze the desired reaction under mild conditions in water and with molecular oxygen as the oxidizing agent. In their current form, these enzymes cleave methyl ether from only specific molecules, mostly those for which they have been optimized over the course of evolution. They are therefore not suitable for widespread use in organic chemistry. The aim of this project is to use modern methods of molecular biology to create new variants (mutants) of this enzyme class that can convert the widest possible range of different methyl ethers to the corresponding alcohols. For this purpose, a well-defined library of different methyl ethers and corresponding alcohols will be synthesized and characterized using classical organic chemistry. By means of suitable high-throughput assays, a large number of mutants can be examined quickly and automatically in their respective biocatalytic conversion of an equally large number of organic substrates. The aim is to efficiently gather information about this exciting family of enzymes and their ability to bring about the desired transformation, and consequently suggest ever even better mutants. Particularly promising candidates will be biocatalytically characterized in depth. The full potential of these novel biocatalysts will be demonstrated in the application on selected complex organic molecules in order to recommend them for wider use as biocatalysts within the community of organic chemists.