Monolithic flow reactor for enzymatic oxidations

Abstract

BACKGROUND Oxidation is among the most important reactions in organic chemistry. Enzymatic oxidation offers a greener alternative to a conventional chemo‐catalytic approach and opens the potential for new reactions. However, inefficient use of expensive enzymes and oxygen (O2) limitations represent particular challenges for biocatalytic reactor design. This work reports a new tubular reactor for continuous flow enzymatic oxidations. RESULTS The reactor comprises a thiol‐functional porous monolith (0.93 ± 0.16 m2 g−1) and an O2‐permeable wall (115 600 ± 1500 mL m−2 day−1). The monolith retains enzyme inside the reactor leading to efficient use. The wall acts as a membrane contactor providing transport of O2 from atmospheric air to the immediate proximity of the enzyme inside the reactor, without any pressure and sparging required. The reactor performance was demonstrated using oxidation of glucose by glucose oxidase (EC 1.1.3.4) coupled with in situ consumption of hydrogen peroxide by horseradish peroxidase (EC 1.11.1.7). At a constant flow rate of 0.1 mL min−1, the product concentration reached 0.10 mmol L−1 after 1.5 h and continued to be relatively high for the next ≥10 h. Overall, the reactor remained active for >40 h using only 15 μg glucose oxidase. Furthermore, the reactor could be rejuvenated by periodic injection of fresh enzyme and thus can operate continuously for extended periods. CONCLUSION We have shown here an alternative approach to efficient enzyme use and O2 delivery. Moreover, with its flexible design, the reactor can be optimized to accommodate a range of gas‐dependent biocatalytic transformations. © 2021 Society of Chemical Industry (SCI).

Off-Stoichiometry Thiol–Enes Polymers Containing Silane Groups for Advanced Packaging Technologies

“…[ 8 , 9 ]. In addition, aptamers [ 10 ] and various enzymes, such as xylanas [ 11 ], horseradish peroxidase [ 12 ], α-chymotrypsin [ 13 ], or glucose oxidase [ 14 , 15 ], can be immobilized on the polymer surface.…”

Controlled Delivery of H2O2: A Three-Enzyme Cascade Flow Reactor for Peroxidase-Catalyzed Reactions

“…37,38 He et al 33 described the immobilization of CPO using the carbohydratebinding lectin protein, concanavalin A (ConA) on silica-coated magnetic nanoparticles (MNPs), with a retention of 80% of initial activity after eight cycles, and 70% ee in the asymmetric synthesis of modafinil. 39,40 Tubular and annular flow reactors have been used for a range of reactions such as oxidation, 41,42 hydrolysis, 43,44 and transesterification reactions. 45,46 Parameters, such as the flow rate and reactor dimensions (ranging from centimeter 47,48 to meter 49−51 ) have been examined in detail to understand the conditions of the reaction environment in the reactor.…”

Functionalized cellulose monolith based affinity chromatography columns for efficient separation of protein molecules

“…2,9 However, due to their gel nature, they suffer from disadvantages such as low strength and permeability, making them difficult to handle. 2 On the other hand, monoliths are porous materials with a three-dimensional network structure of voids and skeletons, used as adsorbents, 10,11 flow reactors, 12,13 catalysts, 14,15 and battery materials. 16,17 They have several advantages such as (i) freely moldable and producible in a capillary column or microchannel device, (ii) low pressure loss enabling high-speed separation by using high flow velocities, thereby shortening the analysis time, (iii) efficient recovery and separation by rapid mass transfer and (iv) possibility of modification through various reactions.…”