A photocatalytic / enzyme cascade reaction catalyst based on porous framework materials, its preparation and application

Abstract

The present invention relates to the synthesis of functionalized porous organic framework materials and their application as heterogeneous photocatalytic biocatalysts in the field of asymmetric catalysis. Creatively, a heterogeneous catalyst is constructed by cascading a porous framework material with photocatalytic function and a biological enzyme. The present invention is a functional porous framework material synthesized from monomers or ligands with photocatalytic function. By varying the monomers and ligands with photocatalytic function, a variety of photocatalysts are synthesized to achieve cascading with biological enzymes. The constructed heterogeneous catalyst has a high yield (59%) and high selectivity (91:9) for the asymmetric catalysis of 2-phenylindole. The heterogeneous photocatalytic biocatalyst prepared by loading a photocatalyst and a biocatalyst breaks the boundary between traditional biocatalysts and traditional photocatalysts. This technology expands the industrial application scope of biocatalysis and provides new ideas for the application of photocatalytic biocatalyst cascades in the field of asymmetric catalysis.

Description

Technical Field

[0001] The present invention belongs to the field of organic functional materials, and particularly relates to a photocatalyst / enzyme cascade reaction catalyst based on a porous framework material, its preparation and application. Background Art

[0002] Following the principles of green, environmental protection, energy conservation and sustainable development, humans have put forward higher requirements for the environmental friendliness of chemical synthesis. Visible light, as a green energy source with rich resources, low cost and renewability, has broad application prospects. How to efficiently and quickly utilize visible light to achieve visible light catalysis by absorbing the energy of visible light through a photocatalyst to cause electron migration is a hot topic in current photocatalysis research, especially one of the popular fields in current organic chemistry research. Visible light catalysis can not only synthesize some simple organic compounds, but also synthesize some complex molecules with biological activities. Therefore, visible light catalysis has become a powerful and efficient organic synthesis method and means.

[0003] Enzyme-catalyzed reactions have high efficiency and high selectivity and play an important role in the synthesis of complex natural products and metabolites. However, in nature, even highly evolved biological enzymes can only catalyze limited reactions, which greatly limits the further application of biological enzymes in organic synthesis. Inspired by photosynthesis (the photo-generated electrons are transferred to the enzyme-catalyzed redox reaction), scientists have recently found that the photocatalyst / enzyme combined catalytic system can effectively solve the problems of single and limited enzyme-catalyzed reactions. It can not only efficiently catalyze the reaction types that natural enzymes can carry out, but also catalyze organic reactions that natural enzymes cannot catalyze. The photocatalytic reaction usually occurs at room temperature or near room temperature, which provides the possibility for combination with enzyme catalysis. In addition, the photocatalytic reaction usually involves electron and energy transfer, and the generated intermediates are stable to water and can be compatible with enzymatic reactions. In order to follow the principle of green development and to reduce waste and cost, chemists have turned their attention to the direction of cascade reactions, combining the reaction activity of chemical catalysts with the selectivity generated by enzyme active sites. At present, the research in this emerging field is attracting the attention of scientists.

[0004] Although more and more important chemo-enzymatic asymmetric chirality can be achieved through photocatalysis, the visible chemo-enzymatic catalytic system still faces some problems and challenges: (1) The commonly used visible light catalysts are not easy to recycle, and the waste will cause heavy metal pollution to the environment, and homogeneous catalysts are prone to decomposition and loss of activity in the photocatalytic reaction. (2) There is a mass transfer resistance between the chemical catalyst and the biological enzyme; (3) Biological enzymes are expensive, have poor chemical stability and thermal stability, and are easy to inactivate. To overcome the limitations of the above chiral catalytic system, the preparation of a photocatalyst / enzyme cascade reaction catalyst based on a porous framework material is of great significance in the field of chiral catalysis.

[0005] With the development of science and technology, more and more new materials are applied to human daily life. Among them, functional porous materials have attracted great attention from researchers due to their irreplaceable roles in many fields such as gas storage and separation, catalysis, and probes. Compared with traditional materials, porous framework materials (metal-organic framework materials, covalent organic framework materials) have good properties such as stable structure, high specific surface area, adjustable pore channels, and designable structure, which are convenient for studying and analyzing their action mechanisms. Constructing them as carriers for immobilized enzymes and photocatalysts can not only achieve efficient loading and precise fixation of the catalysts, but also greatly improve the loading efficiency and stability of the immobilized enzymes and photocatalysts. The characteristics of easy functionalization and post-modification of porous framework materials also provide an excellent platform for improving the interaction between the catalyst and the carrier material to prevent catalyst leakage and developing new reactors for efficient continuous conversion. Summary of the Invention

[0006] The present invention aims to create a photo / enzyme cascade reaction catalyst, synthesize a porous framework material from an organic monomer or organic ligand with photocatalytic function, and maturely use methods such as in-situ encapsulation, adsorption method, covalent method, and cross-linking method to load natural enzymes with chiral catalytic function. Asymmetric catalysis of the photo / enzyme cascade catalytic reaction is achieved.

[0007] On the one hand, the present invention provides a photo / enzyme cascade reaction catalyst based on a porous framework material, characterized in that the catalyst comprises a porous framework material constructed from an organic ligand or organic monomer with photocatalytic function, and a natural enzyme with chiral catalytic function encapsulated therein, and the porous framework material is a metal-organic framework material (MOFs) or a covalent organic framework material (COFs).

[0008] Preferably, the organic ligand or organic monomer with photocatalytic function is selected from any one or more of porphyrin, metal porphyrin, [Ru(bpy)3] 2+ , [Ir(bpy)3] or triphenylamine.

[0009] Preferably, the natural enzyme is selected from any one or more of lipase, alcohol dehydrogenase, olefin reductase carbonyl reductase, monoamine oxidase, and aminotransferase.

[0010] Preferably, the pore diameter of the porous organic framework material is 1-10 nm, and more preferably 3-6 nm.

[0011] Preferably, the metal-organic framework material is selected from one or more of PCN-222, PCN-600, mesoporous UiO-67-RuDCBPY, UiO-67-RuDCBPY-m-MH2, and UiO-67-RuDCBPY-o-NH2, and the covalent organic framework material is selected from one or more of NKCOF-118(M), (M = H, Zn, Cu, Ni).

[0012] On the other hand, the present invention provides an organic monomer or organic ligand for synthesizing a porous framework material, characterized in that the synthesized porous framework material has a photocatalytic function, and the porous framework material has a functional group for immobilizing a biological enzyme or a pore size.

[0013] Preferably, the organic ligand or organic monomer having a photocatalytic function contains any one of porphyrin, metal porphyrin, [Ru(bpy)3] 2+ , [Ir(bpy)3], and a triphenylamine structure.

[0014] Preferably, the pore diameter of the porous organic framework material is 3.0 - 6.0 nm.

[0015] Preferably, the metal-organic framework material is PCN-222, PCN-600, mesoporous UiO-67-RuDCBPY, UiO-67-RuDCBPY-m-MH2, or UiO-67-RuDCBPY-o-NH2.

[0016] Preferably, the covalent organic framework material is NKCOF-118(M) represented by a photocatalytically active porphyrin monomer (M = H, Zn, Cu, Ni).

[0017] On the other hand, the present invention provides a natural enzyme for immobilization, characterized in that the natural enzyme can not only catalyze an asymmetric reaction, but also can perform a cascade reaction with a photosensitizer.

[0018] Preferably, the biological enzyme is any one of lipase, alcohol dehydrogenase, olefin reductase carbonyl reductase, monoamine oxidase, and aminotransferase.

[0019] On the other hand, the present invention provides a method for preparing a photocatalytic / enzyme cascade reaction catalyst based on the porous framework material described above, and the catalyst described above is mainly prepared by any one of in-situ embedding method, adsorption method, or covalent immobilization method.

[0020] Preferably, the preparation of the catalyst described above includes the following steps:

[0021] 1) Add an organic monomer or organic ligand having a photocatalytic function to a reaction vessel, and synthesize a porous framework material by a solvothermal method;

[0022] 2) After the reaction is completed, purify the product;

[0023] 3) Exchange the synthesized porous framework material in a buffer solution and immobilize the natural enzyme with chiral catalytic function to obtain a photo / enzyme cascade reaction catalyst.

[0024] Preferably, the buffer solution is selected from 2-morpholinoethanesulfonic acid, phosphate buffer solution or Tris-HCl at 5-50 mM.

[0025] More preferably, the pH value of the buffer solution is 6-7, and more preferably 6.5.

[0026] On the other hand, the photo / enzyme cascade reaction catalyst based on porous organic framework material of the present invention can be used for the asymmetric catalytic reaction of indole substrates.

[0027] Preferably, the indole substrates are selected from one or more of 2-phenylindole, 2-(4-chlorophenyl)indole, 2-(4-fluorophenyl)indole, 2-(4-bromophenyl)-5-fluoroindole, 2-methylindole, 5-chloro-2-phenyl-1H-indole.

[0028] The natural bioenzyme with chiral catalytic function in the photo / enzyme cascade reaction catalyst.

[0029] Preferably, the asymmetric catalytic yield (59%) and selectivity (80:20) of the photo / enzyme cascade reaction catalyst prepared by immobilizing lipase from wheat germ are the best.

[0030] Preferably, the photocatalytic porous framework carrier for chiral natural enzyme immobilization in the photo / enzyme cascade reaction catalyst is a metal-organic framework material and a covalent organic framework material, which solves the disadvantages of poor stability, poor reusability, and molecular aggregation of immobilized bioenzymes.

[0031] Preferably, in the preparation of the photo / enzyme cascade reaction catalyst, a porous framework material is used to load the natural enzyme. Among them, the immobilized natural enzyme has greatly improved tolerance to organic solvents and temperature.

[0032] Preferably, in the construction of the photo / enzyme cascade reaction catalyst, the metal-organic framework materials (PCN-222, PCN-222, PCN-600, mesoporous UiO-67-RuDCBPY, UiO-67-RuDCBPY-o-NH2) and the covalent organic framework material NKCOF-118 are used to immobilize the natural enzyme with chiral catalysis. The photo / enzyme cascade reaction catalyst has a relatively high yield (59%) and selectivity (80:20) for the asymmetric catalysis of 2-phenylindole.

[0033] Preferably, the catalyst for the photo / enzyme cascade catalytic reaction. Among them, the catalyst constructed by immobilizing lipase with the metal-organic framework material UiO-67-RuDCBPY-m-MH2 has the highest asymmetric catalytic selectivity for 2-phenylindole (91:9).

[0034] Preferably, the solvents for the asymmetric catalytic reaction system are DMF, acetone, acetonitrile, and acetone solvent. Among them, the best reaction solvent is ethanol.

[0035] Preferably, in the asymmetric catalytic reaction of 2-phenylindole by the photo / enzyme cascade reaction catalyst, among them, lipase is immobilized by NKCOF-118. When the optimal loading rate of lipase is 270 mg / g, the yield and selectivity are the highest.

[0036] Preferably, in the photo / enzyme cascade reaction catalyst, NKCOF-118(M) (M = H, Zn, Cu, Ni) immobilizes lipase to catalyze 2-phenylindole, and among them, lipase@NKCOF-118(Zn) has the highest catalytic reaction yield.

[0037] Preferably, the photo / enzyme cascade reaction catalyst has good yields and selectivities for indole derivatives such as 2-(4-chlorophenyl)indole, 2-(4-fluorophenyl)indole, 2-(4-bromophenyl)-5-fluoroindole, 2-methylindole, and 5-chloro-2-phenyl-1H-indole.

[0038] Preferably, the photo / enzyme cascade reaction catalyst based on the porous framework material obtained in the present invention has good asymmetric catalytic performance. Under light irradiation, using the porous framework material as a photosensitizer and the chiral natural enzyme as a chiral inducer, the obtained photo / enzyme cascade reaction catalyst can be used for the synthesis of chiral compounds.

[0039] The photo-asymmetric catalytic activity shows that the obtained photo / enzyme cascade reaction catalyst based on the porous framework material has stable catalysis for the synthesis of chiral compounds and has stable cyclic catalytic activity.

[0040] Preferably, for the obtained photo / enzyme cascade reaction catalyst based on the porous framework material, the porous framework material has a photoactive building unit, a large specific surface area, and a regular and adjustable pore structure, which is beneficial to the efficient utilization of catalytic active sites and the mass transfer of reactants and products during the reaction process. Description of the Drawings

[0041] Figure 1 : Monomer of the photocatalytic function in the photo / enzyme cascade heterogeneous catalyst.

[0042] Figure 2 : Schematic diagram of the synthesis of a covalent organic framework material with photocatalytic performance.

[0043] Figure 3 : Schematic diagram of the photocatalytic reaction in the heterogeneous photocatalytic enzymatic cascade

[0044] Figure 4 : PXRD of the photocatalytic functional material organic framework

[0045] Figure 5 : Standard curve of the Bradford method for lipase

[0046] Figure 6 : Lipase loading curves of covalent organic framework materials with photocatalytic performance (a NKCOF-118; b PCN-222; c PCN-600; d Ru-UiO-67)

[0047] Figure 7 : Solvent and thermal stabilities of the lipase@NKCOF-118 catalyst

[0048] Figure 8 : Determination of the catalytic selectivity of the heterogeneous photocatalytic enzymatic cascade catalyst for substrates. (a lipase@NKCOF-118; b lipase@PCN-222; c lipase@PCN-600; d lipase@Ru-UiO-67)

[0049] Figure 9 : Determination of the recyclability of the heterogeneous photocatalytic enzymatic cascade catalyst

[0050] Figure 10 : Universality of the heterogeneous photocatalytic enzymatic cascade catalyst applied to asymmetric catalysis Detailed implementation methods

[0051] Unless otherwise specified in the context of this application, the technical terms and abbreviations used in this application have the conventional meanings known to those skilled in the art; unless otherwise specified, the raw material compounds used in the following examples are all commercially available.

[0052] As mentioned in the present invention, the synthesis of COFs materials, the immobilization of chiral natural enzymes, and the characterization and testing of various properties are specifically implemented as follows. On the contrary, the following examples are only used to further explain and illustrate the present invention, and should not be regarded as limiting the scope of the present invention, which will only be limited by the claims.

[0053] Example 1:

[0054] Synthesis of covalent organic framework material NKCOF-118 (M = H, Cu, Ni) with bionic structure, the specific implementation steps are as follows: Weigh out monomer 4,4'-(1,4-phenylenebis(ethyne-2,1-diyl))bis(2-methoxybenzaldehyde) (0.04 mmol) and tetraaminoporphyrin (M = H, Cu, Ni) (0.02 mmol) and add them into a thick-walled heat-resistant glass tube. Then add 0.3 mL of o-dichlorobenzene, 1.2 mL of ethanol and 0.2 mL of acetic acid (3 M) aqueous solution. Then quickly freeze it in liquid nitrogen, then evacuate it, and then seal the tube with a hydrogen-oxygen machine flame. Place the sealed glass tube in an oven at 120 °C and react for 3 days to obtain a dark red solid product NKCOF-118 (M = H, Cu, Ni). Its PXRD is as shown in Figure 4 shown.

[0055] Example 2:

[0056] Synthesis of covalent organic framework material NKCOF-118 (Zn) with bionic structure, the specific implementation steps are as follows:

[0057] Weigh out monomer 4,4'-(1,4-phenylenebis(ethyne-2,1-diyl))bis(2-methoxybenzaldehyde) (0.04 mmol) and tetraaminoporphyrin (Zn) (0.02 mmol) and add them into a thick-walled heat-resistant glass tube (o.d.×i.d = 10×8 mm 2 ), then add 0.5 mL of o-dichlorobenzene, 0.5 mL of ethanol and 0.1 mL of 6 M acetic acid aqueous solution. Then quickly freeze it in liquid nitrogen, then evacuate it, and then seal the tube with a hydrogen-oxygen machine flame. Place the sealed glass tube in an oven at 120 °C and react for 3 days to obtain a green solid product NKCOF-118 (M = H, Cu, Ni). Its PXRD is as shown in Figure 4 shown.

[0058] Example 3:

[0059] Synthesis of metal-organic framework material PCN-222 with bionic structure, the specific implementation steps are as follows:

[0060] Mix zirconium tetrachloride (75 mg), tetrakis(4-carboxyphenyl)porphyrin (30 mg) and benzoic acid (1750 mg) in 10 mL of DMF solution and dissolve them completely by ultrasonic wave. Heat the mixed system at 120 °C for 48 hours to obtain purple rod-shaped crystals. Its PXRD is as shown in Figure 4 shown.

[0061] Example 4:

[0062] Synthesis of metal-organic framework material PCN-600 with bionic structure, the specific implementation steps are as follows:

[0063] [Fe3O(OOCCH3)6OH].2H2O (40 mg), tetrakis(4-carboxyphenyl)porphyrin (40 mg) were dissolved in 8 mL of DMF solution, 1.2 mL of trifluoroacetic acid solution was added, the mixed system was transferred to a reaction kettle, and reacted at 150 °C for 20 hours to obtain dark blue needle-like crystals. Its PXRD is as Figure 4 shown.

[0064] Example 5:

[0065] Synthesis of metal-organic framework material Ru-UiO-67 with bionic structure, the specific implementation steps are as follows:

[0066] ZrCl4 (0.5 mmol), [Ru(tpy)(dcbpy)Cl]Cl (0.1 mmol), 4,4'-biphenyldicarboxylic acid (0.4 mmol) and benzoic acid (25 mmol) were mixed and ultrasonically dissolved in DMF solution (20 mL), the mixed system was heated at 120 °C for 24 hours to obtain an orange-red solid. Its PXRD is as Figure 4 shown.

[0067] Example 6:

[0068] Loading curve of lipase on organic framework materials, the specific steps are as follows:

[0069] Weigh 30 mg of activated COFs or MOFs materials, add them to 3 mL of 3 mL 2-morpholinoethanesulfonic acid (MES buffer pH = 6.5) buffer solution containing lipase (10 mg / mL), place it in a shaker at 100 rpm and 37 °C, take out 80 μL every once in a while and dilute it 30 times, and detect the concentration of lipase in the solution at different time periods by Bradford method until the adsorption equilibrium is reached to obtain the adsorption curve of lipase on organic framework materials. The results are as attached Figure 6 shown.

[0070] Example 7:

[0071] Construction of photoenzymatic cascade heterogeneous catalyst, the specific implementation steps are as follows:

[0072] First, weigh 30 mg of covalent organic framework material NKCOF-118(M) and add it to 3 mL of lipase solution (10 mg / mL 50 mM MES buffer, pH = 6.5), incubate at 37 °C and 100 rpm for 1 h, and detect the amount of remaining lipase in the supernatant after adsorption by Bradford method. Through the lipase standard curve (as attached Figure 5 shown), calculate the loading amount of lipase@NKCOF-118(M). Detection wavelength: 595 nm. And substitute it into attached Figure 5Calculate the loading amount (mg / mg) according to the standard curve shown below. The calculation formula is as follows:

[0073]

[0074] Example 8:

[0075] Determination of the enzyme activity of the photoenzymatic cascade heterogeneous catalyst with different lipase loadings. The specific implementation steps are as follows:

[0076] First, the lipase enzyme activity was determined by catalyzing p-nitrophenyl acetate as a substrate to evaluate the activity of lipase. Catalytic system: p-nitrophenyl acetate (0.1 mM, 30 μL) and lipase@NKCOF-118 (M = H, Cu, Ni, Zn) (300 μg of lipase is included in the catalysts with different loadings) were added to 2.97 mL of Tris-HCl buffer (50 mM, pH = 7.4), and detected at 405 nm wavelength for 600 s. Control group: p-nitrophenyl acetate (0.1 mM, 30 μL) and 300 μL of lipase (1 mg / mL) were added to 2.94 mL of Tris-HCl buffer (50 mM, pH = 7.4), and detected at 405 nm wavelength for 600 s.

[0077] Example 9:

[0078] Stability of the photoenzymatic cascade heterogeneous catalyst (resistance to organic solvents and high temperature conditions). The specific implementation steps are as follows:

[0079] First, lipase@NKCOF-118 (M = H, Cu, Ni, Zn) was constructed according to the method of constructing the photoenzymatic heterogeneous catalyst, and its loading amount was calculated. The constructed lipase@NKCOF-118 (M = H, Cu, Ni, Zn) was treated with organic solvents ethanol, methanol, acetone, tetrahydrofuran, DMSO, and DMF for 3 hours respectively, or treated at high temperature conditions (80 °C, 100 °C, and 120 °C) for 3 h, and then the enzyme activity was measured. The control group was to measure the enzyme activity after the same treatment of free lipase with organic solvents and high temperature without dissociation. The results are as shown in the appendix Figure 7 as follows.

[0080] Example 10:

[0081] Specific implementation steps for the asymmetric reaction catalysis of the photoenzymatic cascade heterogeneous catalyst on 2-phenylindole are as follows:

[0082] Weigh out monomer 2-phenylindole (0.03 mmol), lipase@COFs (lipase@NKCOF-118 (M = H, Cu, Ni, Zn)) or lipase@MOFs (lipase@PCN-222, lipase@PCN-600, lipase@Ru-UiO-67) and add them to 1 mL of ethanol solution. After reacting for 24 hours under an oxygen atmosphere, filter, spin-dry the reaction system, and perform column chromatography (eluent: petroleum ether: ethyl acetate 5:1). 1 The structure was determined by 1H-NMR, and its selectivity was detected by liquid chromatography. The results are as Figure 8 shown.

[0083] Example 11:

[0084] Cyclic experiment of the asymmetric catalysis reaction of 2-phenylindole by the photoenzymatic cascade heterogeneous catalyst. The specific implementation steps are as follows:

[0085] Weigh out monomer 2-phenylindole (0.03 mmol), lipase@NKCOF-118 (M = H, Cu, Ni, Zn) (30 mg, 270 mg / mg), and acetone (2 mL) and add them to 1 mL of ethanol solution. After reacting for 24 hours under an oxygen atmosphere, filter, and perform multiple cyclic experiments on the filtered heterogeneous catalyst according to the experimental steps of the first cycle. The yield of the product was further confirmed by column chromatography and liquid chromatography. After 5 times of the experimental results, lipase@NKCOF-118 (M = H, Cu, Ni, Zn) still maintained good yield and selectivity for the asymmetric catalysis of 2-phenylindole. The results are as Figure 9 shown.

[0086] Example 12:

[0087] Weigh out monomer 2-phenylindole derivative (0.03 mmol), asymmetric catalysts such as lipase@NKCOF-118 (M) (30 mg, 270 mg / mg), and acetone (2 mL) and add them to 1 mL of ethanol solution. After reacting for 24 hours under an oxygen atmosphere, filter, spin-dry the reaction system, and perform column chromatography (eluent: petroleum ether: ethyl acetate 5:1). 1 The structure was determined by 1H-NMR, and its selectivity was detected by high performance liquid chromatography. The experimental results show that the heterogeneous catalyst has universality for the asymmetric catalysis of 2-phenylindole derivative substrates. The catalytic results are as shown in the appendix Figure 10 shown.

Claims

1. A photocatalytic / enzyme cascade reaction catalyst based on porous organic framework materials, characterized in that, It includes a porous organic framework material constructed from organic monomers with photocatalytic functions and a natural enzyme with chiral catalytic functions encapsulated therein; The porous organic framework material is NKCOF-118-M, where M = H, Zn, Cu or Ni; the synthesis methods of NKCOF-118-M, where M = H, Zn, Cu or Ni are as follows: Weigh 0.04 mmol of 4,4'-(1,4-phenylenebis(ethyne-2,1-diyl))bis(2-methoxybenzaldehyde) monomer and 0.02 mmol of tetraaminoporphyrin or copper tetraaminoporphyrin or nickel tetraaminoporphyrin monomer and add them into a thick-walled heat-resistant glass tube. Then add 0.3 mL of o-dichlorobenzene, 1.2 mL of ethanol and 0.2 mL of 3M acetic acid aqueous solution. Then quickly freeze it in liquid nitrogen, evacuate the air, and then seal the tube with a hydrogen-oxygen machine flame; put the sealed glass tube into an oven at 120 °C and react for 3 days to obtain a dark red solid product NKCOF-118-M, where M = H, Cu or Ni; Weigh 0.04 mmol of 4,4'-(1,4-phenylenebis(ethyne-2,1-diyl))bis(2-methoxybenzaldehyde) monomer and 0.02 mmol of zinc tetraaminoporphyrin monomer and add them into a thick-walled heat-resistant glass tube. Then add 0.5 mL of o-dichlorobenzene, 0.5 mL of ethanol and 0.1 mL of 6M acetic acid aqueous solution. Then quickly freeze it in liquid nitrogen, evacuate the air, and then seal the tube with a hydrogen-oxygen machine flame; put the sealed glass tube into an oven at 120 °C and react for 3 days to obtain a green solid product NKCOF-118-Zn.

2. The photo / enzyme cascade reaction catalyst according to claim 1, characterized in that, The natural enzyme is any one of lipase, alcohol dehydrogenase, alkene reductase, carbonyl reductase, monoamine oxidase, aminotransferase.

3. The photo / enzyme cascade reaction catalyst according to claim 1, wherein The catalyst is prepared by any one of in-situ embedding method, adsorption method and covalent immobilization method.

4. The photo / enzyme cascade reaction catalyst according to claim 1, wherein It is specifically applied to the asymmetric catalytic reaction of indole substrates.

5. The photo / enzyme cascade reaction catalyst according to claim 4, wherein The indole substrates are selected from one or more of 2-phenylindole, 2-(4-chlorophenyl)indole, 2-(4-fluorophenyl)indole, 2-(4-bromophenyl)-5-fluoroindole, 2-methylindole, 5-chloro-2-phenyl-1H-indole.

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