A compound found in pine trees that is also a waste product from the paper industry has been used by a group of scientists from the Institute for Sustainability and the Department of Chemistry at the University of Bath to make two of the most widely used painkillers in the world, paracetamol and ibuprofen.
Many common pharmaceuticals are made with chemical precursors derived from crude oil, which poses a unique sustainability challenge as the world strives for Net Zero.
A method for making a variety of pharmaceutical precursors from biorenewable pinene, a component of turpentine that is a waste byproduct of the paper industry (annual production >350,000 tons), has been developed by the Bath research team.
They were successful in turning pinene into paracetamol and ibuprofen, two common painkillers that are manufactured annually on 100,000-ton scales.
They were also able to successfully synthesize a number of other turpentine precursor chemicals, including 4-HAP (4-hydroxyacetophenone), which is the precursor of beta-blockers; salbutamol, an asthma inhaler; and other chemicals that are used in perfumes and cleaning products.
Biorenewable paracetamol produced by the team. Credit: University of Bath
They hope that the chemical industry will no longer require crude oil products with this more environmentally friendly “biorefinery” approach.
“Using oil to make pharmaceuticals is unsustainable—not only is it contributing to rising CO2 emissions, but the price fluctuates dramatically as we are greatly dependent on the geopolitical stability of countries with large oil reserves, and it is only going to get more expensive,” stated Dr. Josh Tibbetts, Research Associate in the University’s Department of Chemistry.
Flow reactor used in the synthesis of paracetamol where starting materials are flowed through in a continuous process to give a constant stream of products. Credit: University of Bath
“In the future, we want to replace this with a ‘bio-refinery’ model rather than extracting more oil from the ground.”
“Our turpentine-based biorefinery model squanders synthetic side-effects from the paper business to deliver a range of significant, reasonable synthetics that can be utilized in a large number of uses, from fragrances to paracetamol.”
The method uses continuous flow reactors rather than chemicals in a large reactor to make individual batches of product. This allows production to continue uninterruptedly and makes it easier to scale up.
Even though the current version of the process may be more expensive than using feedstocks based on oil, consumers might be willing to pay a little bit more for pharmaceuticals that are completely made of plants and are sustainable.
The discoveries are distributed in the journal ChemSusChem.
More information: Joshua Dale Tibbetts et al, Sustainable Syntheses of Paracetamol and Ibuprofen from Biorenewable β‐pinene, ChemSusChem (2023). DOI: 10.1002/cssc.202300670
