Light-Driven Biocatalytic Oxidation: A Critical Review of Photoenzymatic Systems

Author: mycolabadmin
2022-09-30
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Summary

This research explores how light can be used to drive enzyme-catalyzed chemical reactions in a more sustainable and environmentally friendly way. Instead of using traditional chemical oxidants that can generate harmful waste, this approach uses light energy to power enzymatic reactions that produce valuable chemicals. Impacts on everyday life: – Enables greener production of pharmaceuticals and chemicals with less environmental impact – Provides new ways to harness solar energy for chemical manufacturing – Could lead to more sustainable industrial processes that reduce chemical waste – May enable production of new drug molecules and materials through novel reaction pathways – Contributes to development of more environmentally friendly chemical processes

Background

Enzymes are the catalyst of choice for highly selective reactions, offering nature-inspired approaches for sustainable chemical synthesis. Oxidative enzymes like monooxygenases, peroxygenases, oxidases, and dehydrogenases catalyze various enantioselective oxyfunctionalization and dehydrogenation reactions under mild conditions. These enzymes require constant supply or withdrawal of reducing equivalents (electrons) to sustain their catalytic cycles. Photocatalysis appears to be a natural choice for accomplishing this electron-relay role.

Objective

This review aims to critically summarize current developments in photoredox biocatalysis, highlight promising concepts, and discuss current limitations in light-driven enzymatic oxidation reactions. The work examines various photocatalytic platforms and their applications in driving oxidative enzyme reactions.

Results

The review found that photobiocatalytic oxidation shows promise but remains in its infancy. Light-driven monooxygenase catalysis shows limited catalytic activities (TTN < 1000). For H2O2-accepting enzymes, light-driven in situ H2O2 generation proves advantageous but is limited by the small number of available UPOs and P450 peroxygenases. Current photochemical systems achieve total turnover numbers (TTN) ranging from 17,500 to 372,000 for certain reactions.

Conclusion

While photobiocatalytic oxidation shows potential for sustainable chemical synthesis, several challenges remain. These include the limited number of suitable redox enzymes, narrow substrate range, and low stability. Future developments require genome mining for new enzymes, protein engineering, and development of whole-cell biocatalysts. Sustainable photobioreactors with optimized light sources, robust photocatalysts, and waste-free electron donors are needed for driving preparative chemistry of peroxygenases and dehydrogenases.

Published in:Chemical Science,
Study Type:Review,
Source: 10.1039/d2sc03483b