Novozym 435-Catalyzed Synthesis of Well-Defined Hyperbranched Aliphatic Poly(β-thioether ester)

• Published in: Molecules
• Main Authors: Wan-Xia Wu, Zi Liu
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2020
• Subjects: novozym 435; poly(β-thioether ester); hyperbranched; acid degradation; oxidation response; Organic chemistry; QD241-441; Antarc*; Antarctica
• Online Access: https://doi.org/10.3390/molecules25030687; https://doaj.org/article/b3e9b1331ce74595a253211bf0c9596e

A series of new hyperbranched aliphatic poly(β-thioether ester)s were prepared by the enzymatic ring-opening polycondensation of 1,4-oxathiepan-7-one (OTO) and AB 2 /ABB’ comonomer with acid-labile β-thiopropionate groups. Two kinds of comonomers, methyl 3-((3-hydroxy-2-(hydroxymethyl)propyl)thio)propanoate (HHTP) and methyl 3-((2,3-dihydroxypropyl)thio)propanoate (DHTP), with different primary alcohols and secondary alcohols, were synthesized by thiol−ene click chemistry and thiol-ene Michael addition, respectively. Immobilized lipase B from Candida antarctica (CALB), Novozym 435, was used as the catalyst. The random copolymers were characterized by 1 H-NMR, 13 C-NMR, GPC, TGA, and DSC. All branched copolyesters had high molecular weights over 15,000 Da with narrow polydispersities in the range of 1.75−2.01 and were amorphous polymers. Their degradation properties under acidic conditions were also studied in vitro. The polymeric nanoparticles of hyperbranched poly(β-thioether ester)s were successfully obtained and showed good oxidation-responsive properties, indicating their potential for biomedical applications.