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(S)-2-chlorophenylglycine ((S)-CPG) is a key chiral intermediate for the synthesis of clopidogrel. Herein, a novel, efficient and environmentally friendly chemo-enzymatic route for the preparation of optically pure (S)-CPG was developed. A straightforward chemical synthesis of the corresponding prochiral keto acid substrate (2-chlorophenyl)glyoxylic acid (CPGA) was developed with 91.7% yield, which was enantioselectively aminated by leucine dehydrogenase (LeuDH) to (S)-CPG. Moreover, protein engineering of LeuDH was performed via directed evolution and semi-rational design. A beneficial variant Es LeuDH-F362L with enlarged substrate-binding pocket and increased hydrogen bond between K77 and substrate CPGA was constructed, which exhibited 2.1-fold enhanced specific activity but decreased thermal stability. Coupled with a glucose dehydrogenase from Bacillus megaterium (Bm GDH) for NADH regeneration, Es LeuDH-F362L completely converted up to 0.5 M CPGA to (S)-CPG in 8 h at 40 °C. • A new chemo-enzymatic catalytic route for (S)− 2-chlorophenylglycine was developed. • Es LeuDH-F362L exhibited enhanced catalytic activity but decreased thermal stability. • Es LeuDH-F362L completely converted up to 0.5 M (2-chlorophenyl)glyoxylic acid in 8 h. [ABSTRACT FROM AUTHOR]

A polymer-templated raspberry assembly method is developed to generally co-assemble proteins and inorganic clusters on the surface of P4VP. The representative GOX-{Mo 72 Fe 30 }@P4VP co-assemblies can efficiently catalyze the oxidation of o-dianisidine with the presence of glucose, where the color change points out their potential in rapid detection of glucose and biomass conversion. [Display omitted] The hybridization of enzymes and inorganics in controlled manner is challenging, however, critical for the development of chemo-enzymatic cascade catalyst with high efficiency and selectivity. Here, proteins and metal oxide clusters can be facilely co-assembled on the surface of colloid of poly(4-vinylpyridine) (P4VP) via hydrogen bonding, due to their enriched surface hydrogen bonding donors. The co-assembly method can be generally applied for preparing chemo-enzymatic catalyst within the selected database of various proteins and metal oxide clusters while the assembly units retain their structures and activities. Typically, a 2.5 nm metal oxide cluster {Mo 72 Fe 30 }, with peroxidase-like activity, are complexed with glucose oxidase (GOX) on P4VP for the catalysis against the oxidization of o-dianisidine (ODA) with the existence of glucose. Due to the synergistic effects of chemical and enzymatic catalysis, the co-assemblies show even higher ODA oxidation activity compared to GOX/catalase bi-enzymatic system, confirming the effectiveness of the co-assembly protocol for cascade catalysis and enabling its applications in rapid glucose detection and biomass conversion. [ABSTRACT FROM AUTHOR]

Notably available from the cellulose contained in lignocellulosic biomass, glucose is a highly attractive substrate for eco-efficient processes towards high-value chemicals. A recent strategy for biomass valorization consists on combining biocatalysis and chemocatalysis to realise the so-called chemo-enzymatic or hybrid catalysis. Optimisation of the glucose conversion to 5-hydroxymethylfurfural (HMF) is the object of many research efforts. HMF can be produced by chemo-catalyzed fructose dehydration, while fructose can be selectively obtained from enzymatic glucose isomerization. Despite recent advances in HMF production, a fully integrated efficient process remains to be demonstrated. Our innovative approach consists on a continuous process involving enzymatic glucose isomerization, selective arylboronic-acid mediated fructose complexation/transportation, and chemical fructose dehydration to HMF. We designed a novel reactor based on two aqueous phases dynamically connected via an organic liquid membrane, which enabled substantial enhancement of glucose conversion (70%) while avoiding intermediate separation steps. Furthermore, in the as-combined steps, the use of an immobilized glucose isomerase and an acidic resin facilitates catalyst recycling. [ABSTRACT FROM AUTHOR]

• Oleic acid was successfully epoxidazed in the presence of lipase catalyst. • Experimental data were produced in a multiphase batch reactor. • Several reaction mechanisms were considered and rate equations were derived. • The proposed kinetic models are useful for molecular-level understanding and process design. The immobilized enzyme lipase acts as an efficient, selective and durable catalyst in the direct transformation of unsaturated carboxylic acids to epoxides, which are used as chemical intermediates and bio-lubricants. Experimental data obtained from the epoxidation of a model molecule, oleic acid in a laboratory-scale isothermal batch reactor were critically evaluated and mathematically modelled in the most precise way. Several rival surface reaction mechanisms were proposed and rate equations based on these mechanisms were derived. The rate equations were implemented in a multiphase model for the laboratory-scale batch reactor and the kinetic and adsorption parameters included in the rate equations were estimated with non-linear regression analysis. Based on the parameter estimation statistics and chemical knowledge, the most plausible kinetic models for the chemo-enzymatic epoxidation of oleic acid on the immobilized lipase catalyst were selected. The best kinetic models gave a good reproduction of the experimental data. The models can be used to predict the performance of enzymatic epoxidation of unsaturated fatty acids. [ABSTRACT FROM AUTHOR]

• A lipase-copper hybrid catalyst was developed via in-situ assembly strategy. • Copper nucleotide composite ensured uniformed distribution of copper nanoparticles. • Hybrid catalyst featured high enzymatic and copper catalytic activity. • Hybrid catalyst enabled highly efficient production of p -AP in cascade reaction. The integration of chemical catalyst and biocatalyst is of great interest due to the accompanying high designability of chemo-enzymatic cascade reactions for sustainable catalytic processes in chemical engineering. Here, a facile strategy is proposed by preparation of a copper ions coordinated cytidine monophosphate (CMP) encapsulated lipase composite via in-situ assembly in aqueous solution which followed by reduction to obtain an enzyme-copper hybrid catalyst. The as-synthesized enzyme-copper nucleotide composite exhibited both high enzymatic activity (6.05 U/mg) and copper-catalytic activity (with reaction rate constant of 8.85 min−1) in the chemo-enzymatic cascade reaction for hydrolysis of p -nitrophenyl butyrate (p -NPB) and generation of p -aminophenol (p -AP), which is a pharmaceutical intermediate for production of analgesics and antipyretics. This study thus sheds light on fabrication of hybrid catalyst under facile conditions, exhibiting potential in development of biosensors, industrial catalysis and biomanufacturing. [ABSTRACT FROM AUTHOR]