(708a) Making Amino Acids from Biomass Via Chemical Catalysis

Current amino acid production is largely based on microbial conversion processes. L-Glutamate, L-lysine, L-threonine, and L-isoleucine production using Corynebacterium glutamicum are all well-established in industry, but these bio-based processes are not without problems. Given the challenges encountered in bio-based amino acid production, there are substantial opportunities for chemists to develop robust chemo-catalytic processes from renewable sources such as biomass. Under the concept of biorefinery, a number of catalytic processes to transform various types of biomass or biomass components, such as cellulose, hemicellulose, lignin, lipids and chitin, into value-added chemicals have been developed in the last two decades, which has been a testament to the power of chemical catalysis in biomass valorization but chemical conversion of biomass into amino acids is rare.[1]

Considering these, we developed a two-step protocol to make several amino acids from sugars.[2] The first step prepares α-hydroxy acids by catalytic transformations of polysaccharides, lignin, and their derivatives using procedures reported in the literature. Following that, the hydroxyl groups are replaced by amine groups to access a series of α-amino acids. To this end, a supported Ru catalyst with high efficiency and recyclability was developed for the desired conversion, allowing six amino acids to be generated from their corresponding α-hydroxy acids. Based on the catalytic system developed in the study, a new two-step chemical process to convert glucose into alanine in 43% yield was demonstrated. Following that, we developed a photo-catalytic pathway to enable the same transformation but reduce the reaction temperature from 200 degree to near room temperature. More recently, we developed one-pot conversion of waste glycerol into alanine[3] and three-step transformation of hemicellulose into proline.

[1] Yan, N.; Wang, Y. Chem, 2019, 5, 739.

[2] Deng, W. et. al. PNAS, 2018, 115, 5093.

[3] Wang, Y. et. al. Angew. Chem. Int. Ed., 2020, 59, 2289.