One of the main factors driving prices in pharmaceuticals, such as cholesterol-lowering drugs and antibiotics, is the cost of production and materials. Researchers at the University of Maine Forest Bioproducts Research Institute (FBRI) have discovered a sustainable method to produce the key ingredient in a broad range of pharmaceuticals, which could help address high prescription drug costs in the U.S.
Among some of the most expensive medications are those that require a chiral center ― a property in which a molecule cannot be superimposed with its mirror image, like right and left hands. Chirality can direct a drug’s biological effects including efficacy, side effects and metabolization. The price of chiral drugs is greatly contributed to the building blocks used during synthesis, which are costly to produce due to complex reaction and purification pathways.
In a new study recently published in Chem, FBRI researchers explore a new, cost-reducing pathway to produce one of these crucial building blocks, (S)-3-hydroxy-γ-butyrolactone (HBL), from glucose at high concentrations and yields.
According to researchers, HBL is a chiral species used for the synthesis of an array of crucial drugs such as statins, antibiotics and HIV inhibitors. Because glucose can be derived from any lignocellulosic feedstock ― such as wood chips, sawdust, tree branches or other woody biomass ― this process opens a new door for the sustainable production of HBL. This approach could also potentially be used to produce other types of important consumer products.
“If we use other kinds of wood sugars, like xylose that is an unneeded byproduct from making pulp and paper, we expect that we could produce new chemicals and building blocks, like green cleaning products or new renewable, recyclable plastics,” said Thomas Schwartz, associate director of FBRI and associate professor in the Maine College of Engineering and Computing who was a lead author for the paper.
In addition to its use as a chiral species, HBL has been identified as a highly valuable precursor to a variety of chemicals and plastics by the U.S. Department of Energy. Previous attempts to produce HBL sustainably achieved only limited success due to safety issues, ineffectiveness or a lack of cost-efficiency.
“The competing processes either lead to low yields, use hazardous starting materials or are just generally costly because of the chosen production scheme and low output,” said Schwartz. “The commercial process is expensive because you have to add the chiral center to the molecule, which doesn’t occur naturally with most petrochemicals.”
Not only does this new approach result in significantly reduced greenhouse gas emissions, but the production costs are also reduced by more than 60% compared to current methods that use petroleum-derived feedstocks. The process can also yield other commercially important chemicals, such as glycolic acid (GA), which presents additional economic opportunities.
The research included work from students in the UMaine Catalysis Group led by Schwartz and was conducted in collaboration with the U.S. Department of Agriculture (USDA) Forest Products Laboratory and the University of Wisconsin-Madison. Funding for the project was provided by the USDA, U.S. Forest Service and the National Science Foundation.