1505 results about "Enzyme catalysis" patented technology

The invention relates to the technical field of organic synthesis, in particular to a method for constructing Orforglipron pyran ring chirality through enzyme catalysis, which comprises the following steps: step S1, taking SM1 and SM2 as raw materials, and reacting under the action of a palladium catalyst and a ligand to obtain INT-1; step S2; carrying out hydrogenation reduction on double bonds of the INT-1 under the catalysis of Pd / C to obtain INT-2; s3, carrying out hydrolysis resolution on the INT-2 in a solvent, a buffer salt system and enzyme catalysis to obtain a chiral pure intermediate INT-3; step S4, performing ring closing on the INT-3 through a Grignard reaction to synthesize a lactone intermediate INT-4; and S5, carrying out Diball-H reduction, quenching, dichloromethane extraction and anhydrous sodium sulfate drying on the INT-4, and then reducing by using triethyl silane to obtain the compound with the general formula A. Chirality is constructed through enzyme catalysis, isomer impurities do not need to be split and separated through SFC when the chirality is constructed, loss is reduced, the yield is increased, and a target product is obtained with high yield and high chiral selectivity; meanwhile, the cost is relatively reduced, and the cost is saved.

The invention discloses silk fibroin composite gel and a preparation method thereof, and relates to the technical field of tissue filling materials. The preparation method of the silk fibroin composite gel comprises the following steps: preparing silk fibroin and carrying out amination modification on the silk fibroin to obtain aminated silk fibroin; carrying out dynamic cross-linking on the aminated silk fibroin and the oxidized sodium alginate through a Schiff base bond by adopting an enzyme catalysis cross-linking process to obtain a dynamic cross-linked network solution; adding a temperature-sensitive component into the dynamic cross-linked network solution, and uniformly mixing to obtain a temperature-sensitive-dynamic dual-network pre-gel solution with temperature responsiveness; loading the active component into the temperature-sensitive-dynamic dual-network pregel solution to obtain a composite gel solution; incubating the composite gel solution to obtain primary gel; after disulfide bonds are introduced into the primary gel, cross-linking strengthening and sterilization are carried out, and the silk fibroin composite gel is obtained. Through temperature-sensitive-dynamic dual-network design, active components and disulfide bonds are introduced to strengthen crosslinking, and the problems that traditional injectable gel is irreversible, single in function, prone to collapse after being filled and the like are systematically solved.

The invention discloses a perchlorate wastewater treatment method which comprises the following steps: discharging perchlorate wastewater into an adjusting tank, and adjusting and buffering water quality in the adjusting tank; discharging the adjusted wastewater into a coagulating basin, and adding a coagulant to react with suspended solids in the wastewater; feeding the wastewater subjected to the coagulation reaction into a sedimentation tank, and completing solid-liquid separation in the sedimentation tank; discharging the precipitate, and enabling the treated wastewater to enter a microbial catalysis tank; perchlorate in the treated wastewater is subjected to biodegradation in a microbial catalysis tank; carrying out MBR (Membrane Biological Reactor) treatment on the wastewater subjected to biodegradation, intercepting microorganisms in the wastewater in a biological catalysis tank, and discharging the wastewater which does not contain the microorganisms and is subjected to biodegradation into an RO (Reverse Osmosis) membrane treatment device; the wastewater is subjected to reverse osmosis treatment at the RO membrane treatment device, reverse osmosis concentrated water is conveyed to the biological catalysis tank, and reverse osmosis fresh water is conveyed back to the water purification tank. The biological enzyme catalysis and membrane separation method is adopted, so that the perchlorate wastewater can be discharged after reaching the standard, and the treatment process is efficient, convenient and low in cost.

The invention discloses a high-performance carbonyl reductase mutant and application thereof in synthesis of a series of chiral alcohols. The high-performance carbonyl reductase mutant is obtained by performing the following mutations on an amino acid sequence as shown in SEQ ID NO.2: the 69th alanine mutates into any one of lysine, leucine, aspartic acid or asparagine, and the 69th alanine mutates into any one of lysine, leucine, aspartic acid or asparagine; and / or the 100th glycine is mutated into any one of glutamic acid, serine, lysine or asparagine. Compared with a wild type enzyme, the thermal stability and the catalytic activity of the obtained mutant are remarkably improved, particularly, single point mutants Mut-A69N, Mut-G100E and Mut-G100N and a combined mutant Mut-A69N-G100N show excellent relative enzyme activity, thermal stability and substrate tolerance. The mutant has high catalytic activity and stability to various chiral alcohols, and the contradiction that the traditional carbonyl reductase is easy to inactivate at high temperature and the catalytic efficiency is difficult to achieve at the same time is solved. The invention provides an efficient and stable enzyme catalysis tool for green biological preparation of chiral drug intermediates.

The invention relates to a silk fibroin biological material with high beta-fold content and a preparation method thereof, and belongs to the technical field of biological extraction. The method comprises the following steps: preparing a regenerated silk fibroin solution; adding an enzyme catalytic promoter and an enzyme into the regenerated silk fibroin solution for incubation; the enzyme catalysis auxiliary agent is selected from one or more of a metal ion catalyst, a zwitterionic surfactant, a functionalized ionic liquid and a calcium phosphate nano-cluster; and centrifuging, cleaning and drying the obtained product to obtain the silk fibroin biological material with high beta-fold content. The silk fibroin material has higher beta-folding amount through primary structure modification, the space structure is more crystallized, and the amino acid sequence is more regular and ordered. The silk fibroin material provided by the invention has excellent mechanical properties, efficiency and yield, and is a biological protein material with great development potential.

The invention belongs to the technical field of separation of products for synthesizing antibiotics by an enzymic method, and particularly relates to a method for separating and recycling an amoxicillin product synthesized by a one-step method based on catalysis of kluyveromyces citricacidophilus beta subunit G385 mutant penicillin acylase. An immobilized penicillin acylase mutant is used for catalyzing penicillin potassium to synthesize amoxicillin in one step, a set of method for separating amoxicillin and phenylacetic acid is developed for an obtained reaction mixture, and the technical scheme mainly comprises the following steps: firstly, separating the immobilized penicillin acylase mutant from a reaction solution through filtration; then, amoxicillin is separated out through crystallization; and then crystallizing, separating and recovering phenylacetic acid through toluene extraction, back extraction and the like. According to the separation method, the amoxicillin can be rapidly and efficiently separated, the yield of the amoxicillin is relatively high, and the average crystallization rate reaches 93.22%; meanwhile, the separation and recovery effects of phenylacetic acid are good; and the extraction agent toluene can be recycled.

The invention provides a chiral resolution method and application of a 3-aryl substituted glutaric acid monoester compound, and the method comprises the following steps: taking a substance as shown in a formula I as a starting raw material, and carrying out alcoholysis to obtain a racemic intermediate as shown in a formula IV; and splitting the intermediate shown in the formula IV, and then dissociating to obtain the compound shown in the formula III, which has a single spatial configuration and an ee value of more than 99%. A cyclic anhydride substrate with a symmetrical structure is used and reacts with alcohol to obtain racemic 3-aryl substituted glutaric acid monoester, a target configuration with high chiral purity is obtained by screening some resolution reagents and solvents and performing salifying resolution on the 3-aryl substituted glutaric acid monoester, the operation is simple, the resolution reagents are easily available in the market and can be recycled, and the method is suitable for industrial production. The method has the advantages that an expensive chiral catalyst or a harsh enzyme catalysis condition is avoided, the reaction cost is reduced, amplified production is facilitated, the ee value of a target configuration can be increased to 99% or above, and the method is an economic and environment-friendly technical route which is simple in post-treatment and convenient for amplified production.

The present disclosure describes a Pseudococcus preparation and a preparation method and application thereof, the Pseudococcus preparation comprises an active ingredient, the active ingredient comprises a specific pro-inflammatory regression mediator (SPMs) and a pro-inflammatory regression mediator (PRMs), the specific proinflammatory regression medium and the proinflammatory regression medium are generated by catalyzing unsaturated fatty acid synthesized by micrococcus by own enzyme. According to the invention, the invention can provide the micrococcus preparation containing the specific proinflammatory regression medium and the proinflammatory regression medium as well as the preparation method and the application of the micrococcus preparation.

The present invention discloses an environmental monitoring system and a monitoring method, which relates to the field of environmental monitoring technology. The system accurately collects the abundance vector MAV of the microbial community within a fixed period, performs concentration and separation treatment, then adds a substrate reaction and monitors the enzyme catalytic reaction in the water sample in real time, generates an enzyme activity feature set EAF, combines the aerobic bacteria change rate Raer, the anaerobic bacteria change rate Ranaer and the correction factor F, forms a multidimensional data set Eac, and establishes a comprehensive water quality assessment algorithm based on this, thereby obtaining a comprehensive water quality detection and assessment index WQI, and realizing a quantitative assessment of the health status of water quality. By comparing with the water quality assessment standard threshold Sthe, an early warning notification is automatically triggered, water quality abnormalities are discovered and responded to in a timely manner, solving the problem that the traditional method cannot capture water quality changes in a timely manner, especially in terms of rapid response to environmental pollution and ecological changes. It has significant advantages.

The invention discloses a molecular modification design method for improving the catalytic activity and the thermal stability of citrobacter vinegaticus-derived hyaluronidase and expression application of the citrobacter vinegaticus-derived hyaluronidase. The interaction of citrobacter vinegaticus hyaluronidase active pocket amino acid residues and hyaluronate tetrasaccharide molecules is visually explored through Pymol, conservative analysis of pocket amino acid evolution is carried out through Consurf, and rational design is carried out through policies of FoldX for calculating enzyme-substrate binding free energy, so that the hyaluronidase catalytic activity is improved. A mutant with significantly improved enzyme activity is obtained through screening, and the thermal stability of the enzyme is further improved through PROSS design and an analysis strategy of mutation site amino acid evolution conservative property and position. According to the invention, the sequence, structure and function of hyaluronidase are deeply studied, and hyaluronidase is mutated from two aspects of stabilizing a catalytic structure and promoting a catalytic reaction, so that a high-activity enzyme with higher application value in industrial production is obtained.

The invention belongs to the technical field of engineered probiotics, and particularly relates to engineered probiotics for radiosensitization and tumor metabolism regulation as well as a preparation method and application of the engineered probiotics. The engineering probiotics comprise probiotics and core-shell type metal nanoparticles which are loaded on the probiotics and are synthesized through a biological directional mineralization effect; the core of the core-shell type metal nanoparticle is a palladium element, and the outer layer of the core-shell type metal nanoparticle is a palladium element and a gold element. The engineering probiotics provided by the invention have excellent enzyme catalysis performance and can target and retain in tumor sites, and through the synergistic effect of all components in the engineering probiotics, adenosine metabolism is effectively inhibited, secretion of pro-inflammatory cytokines is enhanced, tumor microenvironment is promoted to be converted into an inflammatory state, up-regulation of immune checkpoints is inhibited, and the immune checkpoints are inhibited. And T cells are inhibited from being transformed into depletion phenotype and transformed into effect type from depletion type. After the SBRT and the immune checkpoint inhibitor are combined for use, the growth of tumors can be effectively inhibited, and the effect of enhancing immune radiotherapy is achieved.

The invention discloses a rare ginsenoside dammadienol synthetase and an application of the rare ginsenoside dammadienol synthetase in preparation of dammadienol. The dammadienol synthetase is identified for the first time in the research, a metabolic network of a saccharomyces cerevisiae host cell is modified through a metabolic engineering strategy, genes which do not exist in the host cell are introduced into an engineering strain for heterologous expression, the host cell is changed from nothing to existence, and the dammadienol engineering strain is constructed. In addition, through homologous modeling, key catalytic pocket searching and key enzyme gene site-directed mutagenesis modification, enzyme catalysis efficiency is improved, efficient synthesis of dammadienol is achieved, the problem that natural sources of the rare ginsenoside are insufficient is solved, green synthesis and sustainable utilization of the rare ginsenoside are promoted, and the method is suitable for industrial production. And a foundation is laid for subsequent construction of rare ginsenoside cell factories.

The invention discloses an endoglucanase truncated mutant and an application of the endoglucanase truncated mutant. According to the invention, based on endoglucanase BsEGL from bacillus subtilis DLG, a truncated mutant is constructed by deleting a carbohydrate binding domain (CBM) of the endoglucanase BsEGL, and the truncated mutant is named as BsEGL [delta] CBM. Compared with BsEGL, the truncated mutant BsEGL delta CBM has the advantages that the thermal stability, the pH stability, the organic solvent tolerance and the like are remarkably improved, and the activity of degrading phosphoric acid expanded cellulose and corncob xylan is obtained. In addition, the enzymatic activity of the truncated mutant BsEGL delta CBM is remarkably improved by 6.41%, and the catalytic efficiency is remarkably improved. Due to the characteristics, the mutant can be suitable for industrial processes such as feed processing, papermaking, biological energy sources, spinning and food brewing, and is particularly suitable for enzyme catalytic reaction under extreme environments such as high temperature and low pH. The invention provides an enzyme preparation tool with excellent performance for efficient degradation of cellulose biomass, and has important application value.

The invention provides an L-threonine aldolase mutant and application of the L-threonine aldolase mutant in catalytic synthesis of p-methylsulfonylphenylserine, the L-threonine aldolase mutant is derived from pseudomonas, threonine and p-methylsulfonylbenzaldehyde can be used as substrates, and the L-threonine aldolase mutant can be synthesized by using a one-step method. According to the present invention, L-threonine aldolase is adopted as a raw material, pyridoxal phosphate and reduced nicotinamide adenine dinucleotide are adopted as coenzymes, the synthesis of florfenicol intermediate product p-methylsulfonyl phenyl serine is obtained through catalysis, and compared with the wild type L-threonine aldolase, the mutant enzyme has high activity, can effectively improve the conversion efficiency, and can shorten the conversion time; the enzyme and the technical method provided by the invention have the advantages of mild reaction conditions and less pollution, and have good industrial prospects in the production of florfenicol synthesis intermediates.

The invention belongs to the field of protein rational design and enzyme engineering, and particularly relates to a 7beta hydroxysteroid dehydrogenase mutant and application thereof in preparation of UDCA. Firstly, ruminococcus torquens 7beta-hydroxysteroid dehydrogenase is used as a template, hydrogen bonds are increased through homologous modeling prediction, a mutant 7beta-HSDH-3M is obtained through site-specific mutagenesis, the 50-DEG C thermal stability of the obtained 7beta-hydroxysteroid dehydrogenase is remarkably improved, the 7beta-hydroxysteroid dehydrogenase is used for catalyzing 80g / L L7-KLCA to generate UDCA, the conversion rate exceeds 99%, and the 7beta-hydroxysteroid dehydrogenase can be used for preparing a mutant 7beta-HSDH-3M mutant 7beta-HSDH-3M mutant 7beta-HSDH-3M mutant 7beta-HSDH-3M mutant 7beta-HSDH-3M. Complete conversion (greater than 99%) of a product substrate is realized through high conversion rate of 7beta-HSDH.

The invention relates to a color developing agent embedded CuMOFs nano-enzyme paper-based sensor and a preparation method and application thereof.The preparation method comprises the steps that water-soluble TMB-NPs is prepared from water-insoluble typical peroxide mimic enzyme color developing substrates TMB and BSA, the water-soluble TMB-NPs is embedded in CuMOFs in situ through a coprecipitation method, and CuMOFs-TMB-NPs is obtained; the synthesis method is simple and convenient, and the synthesized material has excellent enzyme-like activity and stability. Then, qualitative filter paper is used as a paper-based material, CuMOFs-TMB-NPs is uniformly coated on the paper-based material, and the paper-based sensor of H2O2 and AMP is constructed based on the paper-based material. The CuMOFs disintegrates in an acid environment to release TMB-NPs and a large amount of Cu < 2 + >, the TMB-NPs serves as an enzyme catalysis substrate, and the Cu < 2 + > serves as a catalyst to participate in subsequent reaction. The paper-based sensor can be used for visual detection of H2O2 and AMP in a water body.

The invention belongs to the technical field of biology, and particularly relates to a method for producing xylitol through two-step enzyme catalysis of hemicellulose hydrolysate, and the method comprises the following steps: taking hemicellulose hydrolysate as a raw material, adding arabinose dehydrogenase, NADH oxidase and coenzyme NADH, and carrying out first-step fermentation until no L-arabinose residue exists in fermentation liquor to obtain fermentation reaction liquor I; and adding xylose reductase and glucose dehydrogenase into the fermentation reaction liquid I, and carrying out second-step fermentation to obtain a fermentation product containing xylitol. According to the two-step enzyme catalysis method provided by the invention, xylitol is prepared, and high-purity xylose does not need to be used as a raw material; according to the present invention, the cheap hemicellulose hydrolysate can be directly adopted as the raw material, the xylose conversion rate and the xylitol yield can exceed 99%, the impurity arabitol content in the product is low, the other impurity saccharic acid is easy to separate, and the problems of complex process, large separation difficulty and high cost in the xylitol refining process are successfully solved.

The invention discloses composite gel for osteochondral repair as well as a preparation method and application of the composite gel. Main raw materials of the composite gel are regenerated silk fibroin (RSF) and recombinant humanized III-type collagen (rhCol-III), and auxiliary raw materials of the composite gel are sodium hyaluronate (HA), fibrinogen and thrombin. The preparation method comprises the following steps: firstly, mixing an RSF solution with an rhCol-III solution, obtaining RSF-rhCol particles through a freeze drying technology and mechanical pulverization, dispersing the particles in an HA solution to obtain composite gel, mixing the gel with a thrombin solution, catalyzing fibrinogen to be split and converted into fibrin by thrombin, and performing freeze drying to obtain the rhCol-RhCol-RhCol-RhCol-RhCol-RhCol-RhCol. And crosslinking the fibrous protein monomer to obtain the injectable composite gel preparation capable of immediately gelling. The prepared RSF-rhCol composite gel can adapt to a defect area, has a certain adhesion effect, has excellent biocompatibility, promotes migration of bone marrow mesenchymal stem cells, induces cell differentiation and promotes cartilage tissue regeneration.

The invention provides a method for preparing high-purity phosphatidylserine by a batch enzyme catalysis method based on dynamic choline removal, and belongs to the technical field of enzymatic reaction. According to the method disclosed by the invention, in a reaction system for preparing phosphatidylserine, a byproduct choline is selectively adsorbed by adopting resin. Choline in a reaction system is removed in real time through the integrated adsorption separation module, the enzyme inhibition problem is solved, and meanwhile, the PC conversion rate is larger than or equal to 98% and the PS purity is larger than or equal to 96% in combination with the immobilized enzyme circulation technology; the enzyme can be reused for more than or equal to 20 times (activity retention is more than or equal to 90%); and the choline residual concentration is less than or equal to 0.5 mM (an inhibition threshold value or less).

The invention provides a nitrilase mutant and application of the nitrilase mutant in synthesis of p-cyanobenzoic acid. The invention provides a nitrilase mutant capable of improving the activity of catalytic synthesis of p-cyanobenzoic acid, the mutant protein is a non-natural protein, and the mutant protein can significantly improve the activity of catalyzing p-phthalonitrile to generate p-cyanobenzoic acid. And the mutant protein mutates in two or more core amino acids related to enzyme catalytic activity of the wild nitrilase. The nitrilase mutant provided by the invention can significantly improve the yield of a nitrilase catalytic synthesis product.

The invention discloses an application of oxygen glycosyl transferase coded by a peucedanum praeruptorum PpUGT5 gene in biosynthesis of scopolin, and belongs to the technical field of biology. The nucleotide sequence of the PpUGT5 gene encodes a nucleotide sequence of an amino acid sequence as shown in SEQ ID NO. 2. The scopolamine is obtained by a biosynthesis method for carrying out enzyme catalysis by utilizing the PpUGT5 protein in vitro, and a new method is provided for synthesizing the scopolamine.

The invention discloses a cathepsin B activated fluorescent probe which comprises a dicyanoisosulfone fluorescent report unit and a cathepsin B specific restriction enzyme cutting site GFLG peptide chain. When CTSB specifically cuts a GFLG peptide chain, a DCO molecule with an amino group with relatively strong electron donating ability is generated, so that the fluorescence emission behavior of the probe is rapidly activated through a one-step enzyme catalysis reaction. The invention also provides a preparation method of the cathepsin B activated fluorescent probe. The invention also provides a nano particle for packaging the cathepsin B activated fluorescent probe, and the nano particle is simple in preparation process and mild in reaction condition. The cathepsin B activated fluorescent probe is prepared into nanoparticles, and the nanoparticles can realize accumulation of the material in tumor tissues and accurate imaging in apoptotic tumor cells by enhancing the permeation retention effect, have better biocompatibility and can be used for detecting the apoptotic tumor cells.

The application discloses a galactosyltransferase mutant and application thereof in preparation of flavonoid compounds, and belongs to the technical field of enzymology. The application provides a UDP-galactosyltransferase mutant, which is obtained by site-directed mutation of one amino acid in the amino acid sequence of wild-type galactosyltransferase VcUFGT into alanine (A). The effects of a series of mutants H82A, V139A, G141A, P186A, N245A, V282A and S307A are verified in the examples, the mutants can perform enzyme catalysis reaction with quercetin and UDP-galactoside as substrates, and generate flavonoid compound hyperoside, and the specific enzyme activity of the mutants is more than 1.5 times that of the wild type, thereby providing an effective application basis for biosynthesis of flavonoid compounds.

The invention provides a method for asymmetrically synthesizing an ubugepam chiral intermediate, which comprises the following steps: by taking N-Boc protected ketone ester as a raw material, forming an intermediate II through enamination of ketone and molecular lactam cyclization, obtaining an intermediate III through trifluoroethylation, removing Boc under an acidic condition to obtain an intermediate IV, and carrying out asymmetric synthesis on the intermediate IV under crystallization induction of 5-nitrosalicylaldehyde and chiral acid to obtain the ubugepam chiral intermediate. According to the present invention, the target of dynamic kinetic chiral resolution is achieved through the imine intermediate state, the selective construction of C-3 chirality is achieved, and the chirality of C-5 and C-6 sites is selectively controlled during double-bond cis-catalytic hydrogenation through the chirality of the C-3 site of the substrate so as to obtain the fragment A; the method is efficient, mild and suitable for large-scale production, high performance liquid chromatography chiral resolution is avoided, an expensive metal catalytic coupling step is avoided, application of enzyme catalytic reaction conditions with high technical barriers is avoided, and the amplification performance and the industrial production efficiency of the process are greatly improved.

The invention provides a carbonyl reductase mutant and application thereof in preparation of chiral alcohol compounds, and belongs to the technical field of gene engineering and enzyme catalysis. According to the invention, on the basis of the wild carbonyl reductase, the mutant with activity obviously superior to that of the wild carbonyl reductase is obtained through specific mutation, the selectivity and stability of the enzyme are improved, and the mutant has a wide application prospect in catalytic synthesis of chiral alcohol compounds.

The invention provides a synthesis method of (S)-3-aminobutyronitrile, which specifically comprises the following steps: (1) addition of diketene and ammonia to prepare acetoacetamide; (2) performing an enzyme catalytic reaction on the acetoacetamide obtained in the step (1) in the presence of transaminase, and purifying after the reaction is completed to obtain (S)-3-aminobutanamide; and (3) dehydrating the (S)-3-aminobutanamide obtained in the step (2) to obtain the (S)-3-aminobutyronitrile. According to the synthesis method, the synthesis route is simplified, the production efficiency of the (S)-3-aminobutyronitrile is improved, industrial three wastes are reduced, the use of highly toxic substances is avoided, the cost reduction and benefit improvement in the industrial amplified production are facilitated, and the whole route embodies the value of green chemical synthesis.

The present application relates to the technical field of biocatalysis and biosynthesis, and specifically discloses a blue pigment and a biosynthesis method thereof. In the present application, an indigoidine synthetase and a 4′-phosphopantetheinyl transferase are expressed by a metabolically engineered strain to catalyze the biosynthesis of the blue pigment N-acetyl-indigoidine from glutamine and N-acetylglutamine, and a molecular structure of the blue pigment is inferred by mass spectrometry, nuclear magnetic resonance spectroscopy, etc. The present application achieves the catalytic synthesis of N-acetyl-indigoidine from glutamine and N-acetylglutamine in Escherichia coli (E. coli), Corynebacterium glutamicum (C. glutamicum), Saccharomyces cerevisiae (S. cerevisiae), and Streptomyces. Compared with indigoidine, N-acetyl-indigoidine has a maximum absorption wavelength of 584 nm, and a stable color having high brightness that is not easy to fade. Thus, the blue pigment shows an extensive application range and a promising industrial production prospect.

The invention discloses a dental plaque display type anti-caries invisible appliance based on synergism of iron-based nano-enzyme catalysis and traditional Chinese medicine caries inhibition, and belongs to the field of oral medical instruments. The preparation method of the appliance diaphragm comprises the following steps: preparing a composite material with the functions of catalytically degrading a bacterial biofilm matrix barrier and killing internal bacteria from polyethylene glycol terephthalate-1, 4-cyclohexanedimethanol (PETG) and a Fe3O4 nano-enzyme filler in a solution blending manner; and after the composite material is subjected to thermoplastic molding, a layer of molecularly imprinted polymer (MIP)-spiropyrane and chitosan-magnolol are coated with the fluorescent display agent which is prepared by mixing the molecularly imprinted polymer (MIP)-spiropyrane and the chitosan-magnolol. The iron-based nano-enzyme can catalytically degrade a bacterial biofilm matrix barrier and kill internal bacteria, and the MIP-spiropyrane fluorescent display agent can specifically display the accumulation condition of cariogenic bacterial plaque in the oral cavity under ultraviolet irradiation. The invisible orthodontic appliance can reduce or prevent caries while having the same orthodontic effect as other orthodontic appliances in the market.

The invention belongs to the technical field of perfume synthesis, and particularly relates to a method for efficiently preparing chiral oxo-ionol by an enzymic method, which comprises the following steps: putting a substrate containing oxo-ionone and an auxiliary substrate into a buffer solution, and stirring at room temperature until complete dissolution to obtain a substrate solution; the method comprises the following steps: dispersing carbonyl reductase ChKRED20 or a mutant thereof and coenzyme into a substrate solution, and carrying out heat preservation and stirring; and after the reaction is finished, adding water to dilute, extracting with ethyl acetate, washing with water, drying, and concentrating the ethyl acetate to obtain the chiral oxo-ionol. The enzyme catalysis method disclosed by the invention is mild in reaction condition and high in selectivity, and a target product can be obtained at high yield at room temperature and normal pressure. The coenzyme is regenerated by adopting a substrate coupling method, the use amount of the coenzyme is reduced, and a substrate coupling strategy that an auxiliary substrate is used as a substrate is adopted, so that a reaction system is simple, products are easy to separate, and the cost is reduced. According to the technical scheme, the conversion rate is greater than 99%, the ee value of the product reaches 99% or above, and the industrial application value is achieved.

The invention belongs to the field of biological catalysis, and particularly relates to a method for preparing oxidized nicotinamide adenine dinucleotide phosphate through double-enzyme coupling. According to the invention, through construction and optimization of a one-pot double-enzyme coupled catalytic system, a genetically engineered bacterium containing nicotinamide mononucleotide adenosine transferase NMNAT and a genetically engineered bacterium containing NAD kinase are used as a whole-cell catalyst, nicotinamide mononucleotide NMN is used as a starting substrate, adenosine triphosphate, polyphosphate and divalent metal ion salt are added, and the whole-cell enzyme is prepared through a one-pot method. The oxidized nicotinamide adenine dinucleotide phosphate NADP < + > is efficiently and catalytically synthesized by a one-pot method, and the whole-cell catalytic reaction liquid is separated and purified to obtain the NADP < + >. The double-enzyme catalysis method disclosed by the invention is short in reaction route, high in atom economy, capable of reducing the existing production cost, short in production period, easy for downstream separation and purification, and suitable for large-scale and large-scale production of NADP < + >.