Optically Active β-Methyl-δ-Valerolactone: Biosynthesis and Polymerization

Abstract

Chemo-enzymatic pathways were developed to prepare optically enriched (+)-β-methyl-δ-valerolactone and (−)-β-methyl-δ-valerolactone. Anhydromevalonolactone, synthesized by the acid-catalyzed dehydration of bioderived mevalonate, was transformed to (+)-β-methyl-δ-valerolactone with 76% ee and 69% conversion using the mutant enoate reductase, YqjM(C26D, I69T). With the same substrate but a different enoate reductase (OYE2), we obtained the other enantiomer ((−)-β-methyl-δ-valerolactone) with higher selectivity and yield (96% ee and a 92% conversion). The enzymedocking program LibDock was used to help explain the origin of the divergent enatntioselectivity of the two reductases, and complementary in vitro experiments were used to determine the turnover number and Michaelis constant for each. Finally, the effect of the enantiopurity of the β-methyl-δ-valerolactone monomer on the properties of the corresponding polyester was investigated. Like atactic poly((±)-β-methyl-δ-valerolactone), the isotactic polymer was determined to be amorphous with a low softening temperature (−52 °C).

Polymers from sugars: cyclic monomer synthesis, ring-opening polymerisation, material properties and applications

“…Chemo-enzymatic pathways have also allowed the preparation of optically enriched bMdVL from anhydromevalonolactone. 43 Angelica lactone. Distillation of levulinic acid (LevA) under reduced pressure 44 or intramolecular dehydration in the presence of an acid catalyst such as acetic anhydride 45 or phosphoric acid 46 yields a-Angelica lactone (AL) monomer 7 ( Fig.…”

“…41b Isotactic poly((À)-bMdVL), obtained by ROP of (À)-bMdVL with BnOH initiator and DPP catalyst, was shown to remain amorphous with similar T g to the atactic polymer. 43 ROP of angelica lactone. a-AL (7) features two functional groups capable of polymerisation: the lactone ring and an endocyclic carbon-carbon double bond.…”

Preparation and Characterization of Waterborne Polyurethane with Unique Nanoparticles by Controlling Water

“…To further investigate the hydrolytic stability, the swelling behavior of the samples in deionized water and organic solvent (THF) was performed in 7 days or longer. The degradability of both the samples was performed by putting their films through water swelling measurement [39][40][41][42]. As depicted in Fig.…”

Discovery, Characterization, Engineering, and Applications of Ene-Reductases for Industrial Biocatalysis

“…The generation of optically enriched (+)- and (-)-β-methyl-δ-valerolactones was achieved using the ERs YqjM variant C26D/I69T from Bacillus subtilis and OYE2 from S. cerevisiae , respectively (Scheme 4A). These products were used to generate atactic and isotactic amorphous poly((±)-β-methyl-δ-valerolactone polymers with a low softening temperature 58. Interestingly, an alternative fermentation approach to valerolactone, levulinic acid, and derivatives of both was recently patented, utilising organisms such as engineered S. cerevisiae and Pichia stipitis 59.…”

“…Interestingly, an alternative fermentation approach to valerolactone, levulinic acid, and derivatives of both was recently patented, utilising organisms such as engineered S. cerevisiae and Pichia stipitis 59. This included a step whereby an ER was employed for the reduction of 4-hydroxy-2-oxo-pentanoic acid into levulinic acid 58…”