A simple one-step synthesis of alkylation product from cyclic allylic alcohol and resorcinol

Seung-Hwa Baek; Young-Ok Kim

doi:10.1007/bf02974103

Hybrid Chemo-Biocatalysts Prepared in One Step from Zeolite Nanocrystals and Enzyme-Polyelectrolyte Complexes

10.26434/chemrxiv.12746729.v1 ◽

2020 ◽

Author(s):

Margot Van der Verren ◽

Valentin Smeets ◽

Aurélien vander Straeten ◽

Christine C. Dupont-Gillain ◽

Damien Debecker

Keyword(s):

Spray Drying ◽

Heterogeneous Catalysts ◽

Enzyme Stability ◽

Allylic Alcohol ◽

Intrinsic Activity ◽

Hybrid Catalyst ◽

One Pot ◽

Polyelectrolyte Complexes ◽

Hybrid Catalysts ◽

One Step

The combination of heterogeneous catalysts and enzymes, in so-called hybrid catalysts, is an attractive strategy to effectively run chemoenzymatic reactions. Yet, the preparation of such bifunctional materials remains challenging because both the inorganic and the biological moieties must be integrated in the same solid, while preserving their intrinsic activity. Combining an enzyme and a zeolite, for example, is complicated because the pores of the zeolite are too small to accommodate the enzyme and a covalent anchorage on the surface is often ineffective. Herein, we developed a new pathway to prepare a hybrid catalyst built from glucose oxidase and TS-1 zeolite. Such hybrid material can catalyze the in situ formation of H2O2, which is subsequently used by the zeolite to trigger the epoxidation of allylic alcohol. Starting from an enzymatic solution and a suspension of zeolite nanocrystals, the hybrid catalyst is obtained in one step, using a continuous spray drying method. While enzymes are expectedly unable to resist the conditions used in spray drying (temperature, shear stress, etc.), we leverage on the preparation of “enzyme-polyelectrolyte complexes” (EPCs) to increase the enzyme stability. Importantly, the use of EPCs also appears to prevent enzyme leaching and to stabilize the enzyme against pH changes. We show that the one-pot preparation by spray drying gives access to hybrid catalysts with unprecedented performance in the targeted chemoenzymatic reaction. Interestingly, the hybrid catalyst performs much better than the two catalysts operating as separate entities. We anticipate that this strategy could be used as an adaptable method to prepare other types of multifunctional materials.<br>

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Hybrid Chemo-Biocatalysts Prepared in One Step from Zeolite Nanocrystals and Enzyme-Polyelectrolyte Complexes

10.26434/chemrxiv.12746729 ◽

2020 ◽

Author(s):

Margot Van der Verren ◽

Valentin Smeets ◽

Aurélien vander Straeten ◽

Christine C. Dupont-Gillain ◽

Damien Debecker

Keyword(s):

Spray Drying ◽

Heterogeneous Catalysts ◽

Enzyme Stability ◽

Allylic Alcohol ◽

Intrinsic Activity ◽

Hybrid Catalyst ◽

One Pot ◽

Polyelectrolyte Complexes ◽

Hybrid Catalysts ◽

One Step

The combination of heterogeneous catalysts and enzymes, in so-called hybrid catalysts, is an attractive strategy to effectively run chemoenzymatic reactions. Yet, the preparation of such bifunctional materials remains challenging because both the inorganic and the biological moieties must be integrated in the same solid, while preserving their intrinsic activity. Combining an enzyme and a zeolite, for example, is complicated because the pores of the zeolite are too small to accommodate the enzyme and a covalent anchorage on the surface is often ineffective. Herein, we developed a new pathway to prepare a hybrid catalyst built from glucose oxidase and TS-1 zeolite. Such hybrid material can catalyze the in situ formation of H2O2, which is subsequently used by the zeolite to trigger the epoxidation of allylic alcohol. Starting from an enzymatic solution and a suspension of zeolite nanocrystals, the hybrid catalyst is obtained in one step, using a continuous spray drying method. While enzymes are expectedly unable to resist the conditions used in spray drying (temperature, shear stress, etc.), we leverage on the preparation of “enzyme-polyelectrolyte complexes” (EPCs) to increase the enzyme stability. Importantly, the use of EPCs also appears to prevent enzyme leaching and to stabilize the enzyme against pH changes. We show that the one-pot preparation by spray drying gives access to hybrid catalysts with unprecedented performance in the targeted chemoenzymatic reaction. Interestingly, the hybrid catalyst performs much better than the two catalysts operating as separate entities. We anticipate that this strategy could be used as an adaptable method to prepare other types of multifunctional materials.<br>

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An Interactive Minicomputer Program for the Indexing and Simulation of Electron Diffraction Patterns

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100092670 ◽

1976 ◽

Vol 34 ◽

pp. 542-543

Author(s):

R.P. Goehner ◽

W.T. Hatfield ◽

Prakash Rao

Keyword(s):

Electron Diffraction ◽

Real Time ◽

Pattern Analysis ◽

Flow Diagram ◽

Hard Copy ◽

Time Analysis ◽

Real Time Analysis ◽

Transmission Electron ◽

One Step ◽

Diffraction Patterns

Computer programs are now available in various laboratories for the indexing and simulation of transmission electron diffraction patterns. Although these programs address themselves to the solution of various aspects of the indexing and simulation process, the ultimate goal is to perform real time diffraction pattern analysis directly off of the imaging screen of the transmission electron microscope. The program to be described in this paper represents one step prior to real time analysis. It involves the combination of two programs, described in an earlier paper(l), into a single program for use on an interactive basis with a minicomputer. In our case, the minicomputer is an INTERDATA 70 equipped with a Tektronix 4010-1 graphical display terminal and hard copy unit.A simplified flow diagram of the combined program, written in Fortran IV, is shown in Figure 1. It consists of two programs INDEX and TEDP which index and simulate electron diffraction patterns respectively. The user has the option of choosing either the indexing or simulating aspects of the combined program.

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Nutrient-regulated gene expression in eukaryotes

Biochemical Society Symposium ◽

10.1042/bss0730085 ◽

2006 ◽

Vol 73 ◽

pp. 85-96 ◽

Cited By ~ 8

Author(s):

Richard J. Reece ◽

Laila Beynon ◽

Stacey Holden ◽

Amanda D. Hughes ◽

Karine Rébora ◽

...

Keyword(s):

Gene Expression ◽

Rna Polymerase ◽

Rna Polymerase Ii ◽

Transcriptional Control ◽

Direct Interaction ◽

Signalling Pathways ◽

A Cell ◽

One Step ◽

Higher Eukaryotes ◽

Regulated Gene Expression

The recognition of changes in environmental conditions, and the ability to adapt to these changes, is essential for the viability of cells. There are numerous well characterized systems by which the presence or absence of an individual metabolite may be recognized by a cell. However, the recognition of a metabolite is just one step in a process that often results in changes in the expression of whole sets of genes required to respond to that metabolite. In higher eukaryotes, the signalling pathway between metabolite recognition and transcriptional control can be complex. Recent evidence from the relatively simple eukaryote yeast suggests that complex signalling pathways may be circumvented through the direct interaction between individual metabolites and regulators of RNA polymerase II-mediated transcription. Biochemical and structural analyses are beginning to unravel these elegant genetic control elements.

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