Light feed enzymes create valuable chiral molecules from plant -based construction blocks

A pioneering research laboratory at the University of Illinois Urbano-Champaign has achieved another milestone using light-driven enzymatic reactions to convert simple biological construction blocks into valuable chemicals.

The researchers, part of the Advanced Innovation Center for Bioenergy and Bioproducts (CABBI), developed a clean and efficient way to make complex chemicals called chiral ketones through photocatalysis, combining bioingenic enzymes with light to create novel reactions.

“Enzymes are powerful catalysts, but they are limited by the narrow scope of their reactivity for industrial applications. In this work, we have successfully demonstrated that enzymes with new reactivity to nature can be created by light,” said the leader of Cabbi Huimin Zhao conversion, corresponding author of the study.

Zhao, whose laboratory has used this approach to produce other valuable chemical reactions, is a professor of Chemical and Biomolecular Engineering (CHBE), thematic Biosystems Design Leader at the Carl R. WOESE for Genomic Biology (IGB) Institute Biofoundry Applications in Illinois.

The new study, published in Nature catalysis, It was directed by the first authors Zhengyi Zhang and Maolin Li, postdoctoral Research Associates with Cabbi, Chbe and IGB.

Many useful chemicals, especially in agrochemicals and medications, exist in two forms of mirror image, such as left and right hands. These are called chiral molecules, already often just a “hand” is effective or safe. While chemists can build chiral molecules from scratch using an asymmetric catalysis strategy, this process can be complex and expensive.

In contrast, make a rankic mixture, a 50:50 mixture of both mirror image forms, it is often easier and cheaper. That is why another approach, called enantioconvergente catalysis, is so valuable: it allows both versions in a rankic mixture to become the product of a chirality. However, most current methods can only do this when the stereocentro is close to the reactive site of the molecule. Reaching remote stereocentros, parts that are further and more difficult to access, remains a great challenge.

In this study, scientists solved the problem by using a photoenzimatic reaction. When exposed to light, the enzyme generates a radical centered on nitrogen, a very reactive intermediate that can break the remote chiral carbon hydrogen bond through a process called 1.5-hydrogen atom transfer.

The enzyme carefully reconstructs this molecule bond by transferring hydrogen atoms, choosing a preferred “hand”. This method allows both forms of the starting material to be channeled in the same chiral product, even when the original chiral center is far from the reaction center, offering a precise and ecological form of making chiral molecules with complicated structures.

“All were baffled at the beginning: we were studying a different reaction that involved radicals centered on nitrogen when this unexpected result appeared,” Zhang said. “I’m glad we have not missed this interesting discovery.”

It is important to note that the ketones used in this investigation can easily derive from fatty acids C6 and C12 found in plant biomass. This creates a new opportunity to transform renewable carbon sources such as bioenergy crops into high -value molecules, supporting Cabbi’s mission to build sustainable bioman -abuse platforms based on raw materials derived from plants.

This approach is aligned with broader objectives of developing innovative technologies for sustainable bioeconomy. It offers a cleaner and efficient way to make the specific forms of “delivered” molecules necessary for medications, agrochemicals and other daily products. By using light and enzymes to convert cheap and easy to make mixtures into high value compounds, the method can reduce chemical costs and waste, which makes it practical and ecological.

The study co -authors included Wesley Harrison, Jingxia Lu and Yujie Yuan, all of Chbe and IGB; and Zhenxiang Zhao of the Department of Chemistry of Illinois.