5512-72-1Relevant articles and documents
Novozym 435-Catalyzed Synthesis of Well-Defined Hyperbranched Aliphatic Poly(β-thioether ester)
Liu, Zi,Wu, Wan-Xia
, (2020/02/18)
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 AB2/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 1H-NMR, 13C-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.
Stereoselective desymmetrizations by recombinant whole cells expressing the Baeyer-Villiger monooxygenase from Xanthobacter sp. ZL5: A new biocatalyst accepting structurally demanding substrates
Rial, Daniela V.,Bianchi, Dario A.,Kapitanova, Petra,Lengar, Alenka,Van Beilen, Jan B.,Mihovilovic, Marko D.
scheme or table, p. 1203 - 1213 (2009/04/07)
In this work the substrate profile and stereoselectivity of engineered whole cells overexpressing the Baeyer-Villiger monooxygenase from Xanthobacter sp. ZL5 with respect to biotransformations of prochiral substrates is characterized. This enzyme catalyzes the desymmetrization of cyclic ketones bearing different chemical features with stereoselectivity similar to that obtained with a related protein from Acinetobacter as a prototype representative of the cyclohexanone monooxygenase enzyme cluster. Moreover, this biocatalyst is able to convert sterically demanding substrates previously not transformed by other enzymes with excellent enantioselectivities. These results expand the repertoire of optically pure lactones accessible by whole-cell biotransformation processes, which are useful intermediates for the synthesis of natural and bioactive products. In addition, we observed a remarkable epoxidation reaction of a non-activated C=C bond catalyzed by this monooxygenase. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
