Vine-Twining Inclusion Behavior of Amylose towards Hydrophobic Polyester, Poly(β-propiolactone), in Glucan Phosphorylase-Catalyzed Enzymatic Polymerization

Abstract

This study investigates inclusion behavior of amylose towards, poly(β-propiolactone) (PPL), that is a hydrophobic polyester, via the vine-twining process in glucan phosphorylase (GP, isolated from thermophilic bacteria, Aquifex aeolicus VF5)-catalyzed enzymatic polymerization. As a result of poor dispersibility of PPL in sodium acetate buffer, the enzymatically produced amylose by GP catalysis incompletely included PPL in the buffer media under the general vine-twining polymerization conditions. Alternatively, we employed an ethyl acetate–sodium acetate buffer emulsion system with dispersing PPL as the media for vine-twining polymerization. Accordingly, the GP (from thermophilic bacteria)-catalyzed enzymatic polymerization of an α-d-glucose 1-phosphate monomer from a maltoheptaose primer was performed at 50 °C for 48 h in the prepared emulsion to efficiently form the inclusion complex. The powder X-ray diffraction profile of the precipitated product suggested that the amylose-PPL inclusion complex was mostly produced in the above system. The 1H NMR spectrum of the product also supported the inclusion complex structure, where a calculation based on an integrated ratio of signals indicated an almost perfect inclusion of PPL in the amylosic cavity. The prevention of crystallization of PPL in the product was suggested by IR analysis, because it was surrounded by the amylosic chains due to the inclusion complex structure.

Bottom‐Up Synthesized Glucan Materials: Opportunities from Applied Biocatalysis

“…[29a,c] Noncovalent interactions between amylose and guest polymers may contribute to the formation of highly ordered supramolecular structures. [181] Oligomers such as oligo[(R)-3-hydroxybutyrate] [182] and polymers such as PTHF, [183] poly(𝛿-valerolactone), [184] poly(trimethylene carbonate), [185] poly(𝛽-propiolactone), [186] and poly(𝛾-butyrolactone) [187] are utilized for inclusion complex formation via vine-twining polymerization. The hydrophobicity, molecular weight, and chirality of guest polymers significantly influence complexation with amylose.…”

Fabrication of Nanostructured Supramolecules through Helical Inclusion of Amylose toward Hydrophobic Polyester Guests, Biomimetically through Vine-Twining Polymerization Process

“…Such microparticles probably acted as stabilizers, giving rise to the formation of the emulsion system. When the GP-catalyzed enzymatic polymerization was conducted in the emulsion system containing dispersed PPL, helical inclusion of the enzymatically produced amylose toward PPL occurred, producing the amylose-PPL inclusion complex (Figure 3) [38]. It will be possible that PGA, which had not complexed with amylose through vine-twining polymerization also due to the poor dispersibility, could form of an inclusion complex by employing a similar emulsion system.…”