Biocatalysis for terpene-based polymers

Abstract

Accelerated generation of bio-based materials is vital to replace current synthetic polymers obtained from petroleum with more sustainable options. However, many building blocks available from renewable resources mainly contain unreactive carbon-carbon bonds, which obstructs their efficient polymerization. Herein, we highlight the potential of applying biocatalysis to afford tailored functionalization of the inert carbocyclic core of multicyclic terpenes toward advanced materials. As a showcase, we unlock the inherent monomer reactivity of norcamphor, a bicyclic ketone used as a monoterpene model system in this study, to afford polyesters with unprecedented backbones. The efficiencies of the chemical and enzymatic Baeyer–Villiger transformation in generating key lactone intermediates are compared. The concepts discussed herein are widely applicable for the valorization of terpenes and other cyclic building blocks using chemoenzymatic strategies.

Lactone monomers obtained by enzyme catalysis and their use in reversible thermoresponsive networks

“…reported the synthesis of norcamphor lactone on 80 mmol scale, in 81% yield and 5 days reaction time which opened the door to further investigations to modulate the entire process in order to further scale it up to a better yield. We have previously reported that an engineered thermostable variant of CHMO Acineto , harboring four substitutions and referred to as CHMO Acineto _QM, was able to fully convert the nonnatural bulky substrate norcamphor (the major product is the normal lactone, 93.4%) and act on the more substituted substrate (−)‐ cis ‐verbanone . Scaling up this transformation from 2 to 33 mM of the substrate norcamphor in shake‐flask enabled the biosynthesis of norcamphor lactone in 0.5 g scale, stressing the high potential of the enzyme CHMO Acineto _QM to be used for the production of industrially relevant products (Scheme ).…”

Prospects of Using Biocatalysis for the Synthesis and Modification of Polymers

“…The resulting lactone can be subjected to enzymatic polymerization or polymerized chemically. The beneficial application of Baeyer–Villiger monooxygenases was demonstrated in the preparation of lactones from terpene derivatives, where the use of the classical approach with hydrogen peroxide would be impossible due to the formation of a significant amount of by-products [ 71 , 73 ]. The limiting factor when using this type of monooxygenases is the need to regenerate the coenzyme NAD(P)H. To solve this problem, NAD(P)H cyclic regeneration systems based on alcohol dehydrogenase or glucose oxidase with appropriate substrates were used together with monooxygenase [ 70 , 72 ].…”

Synthesis of Functionally and Stereochemically Diverse Polymers via Ring-Opening Metathesis Polymerization of Derivatives of the Biomass-Derived Platform Molecule Levoglucosenone Produced at Industrial Scale

“…These materials, which may or may not be biodegradable, can be produced, inter alia, from biomass-derived platform molecules (BMDPMs). − Notable examples of such processes include the ring-opening polymerization (ROP) of carbohydrate- and lignocellulosic-derived lactones , as well as via the ring-opening metathesis polymerization (ROMP) of fungal metabolites such as the unsaturated and macrocyclic glycolipid lactonic sophorolipid (LSL) . Other lipids, particularly fatty acids, have been exploited for such purposes, as have terpenoids . Another appealing approach involves exploiting fermentation products such as itaconic acid as the starting monomers .…”