449 results about "Cascade reaction" patented technology

The invention discloses a biosynthesis system for high-yield 1, 6-hexamethylenediamine and application of the biosynthesis system, and belongs to the technical field of biology. According to the method, key genes which are excavated and optimized in a 1, 6-hexamethylenediamine biosynthetic pathway are co-expressed in a single cell module or a multi-cell module, and different enzyme elements expressed by the cell module are subjected to enzyme cascade reaction, so that 1, 6-hexamethylenediamine can be efficiently synthesized by taking caprolactam or 6-aminocaproic acid as a substrate; furthermore, after the carboxylic acid reductase MaCAR is mutated, the catalytic activity of the carboxylic acid reductase MaCAR can be remarkably improved, and the yield of the 1, 6-hexamethylenediamine is further improved; in addition, the biosynthesis system disclosed by the invention directly takes the cell module as a whole-cell catalyst, and an enzyme purification step is avoided, so that the biosynthesis system has the advantage of low cost.

The invention discloses a preparation method of a pyrazolone amino-acid ester derivative. The pyrazolone amino-acid ester derivative is obtained through three-component cascade reaction by taking pyrazolone imine, a pentafluorophenylacetate derivative and alcohol as reactants and chiral isothiourea as a catalyst. According to the invention, challenges of competitive side reactions between a plurality of reaction substrates and intermediates and stereoselectivity control are overcome, the application range of the substrate combination of the existing system is broken through, and synthesis of a series of pyrazolone amino-acid ester derivatives is realized in a green and efficient manner. According to the method disclosed by the invention, substrate preassembly is not needed, transition metal catalysis is not needed, raw materials and the catalyst are cheap and easy to obtain, reaction conditions are mild, and the substrate application range is wide. In addition, the invention also provides a new way for introducing the medicine bioactive molecules into the synthesis of the pyrazolone amino-acid ester compound.

The invention discloses a formate dehydrogenase mutant and application of the formate dehydrogenase mutant in catalysis of carbon dioxide reduction, the 223 arginine (Arg) of an amino acid sequence of formate dehydrogenase PsFDH48 derived from Paracoccus sp. MKU1 is mutated into proline (Pro) or the 242 proline (Pro) is mutated into phenylalanine (Phe) through a site-specific mutagenesis technology, and the obtained mutants R223P and P242F have higher catalytic activity and can be applied to catalysis of carbon dioxide reduction. The catalyst can catalyze CO2 to generate formic acid more effectively in vitro, and has potential application value in the aspects of efficient activation of CO2 and further conversion of CO2 into other mono-carbon compounds through cascade reaction.

The invention relates to the technical field of sewage treatment, and particularly provides a method and a system for realizing beneficiation wastewater N, N-diethyldithiocarbamate-C-N-S synergistic oxidation-reduction coupling treatment by an MABR oxygen layering process. According to the method and the system, a time sequence dissolved oxygen (DO) dynamic regulation and control strategy is innovatively developed: through periodic / pulse type switching anaerobic-hypoxia-aerobic conditions, oxygenolysis and ammonification reaction of N, N '-diethyldithiocarbamate are intensified directionally, and toxicity inhibition of intermediate products on functional bacteria is relieved. Based on the strategy, the system can accurately utilize biological membrane oxygen gradient spatial distribution in a single MABR reactor to realize a cascade reaction of sulfur oxidation-ammonification-aerobic nitrification-anoxic denitrification of ethyl sulfur nitrogen; or aiming at high-concentration diethyldithiocarbamate (gt; 50 mg / L) is coupled with a front anaerobic reactor, and ammoniation detoxification and denitrification nitrogen removal are enhanced.

The invention discloses a novel biosynthesis path for producing 3 '-phosphoadenosine-5'-phosphosulfuric acid and application, and belongs to the technical field of bioengineering. According to the invention, through recombinant expression and purification of ribose kinase, ribose phosphate pyrophosphate kinase, ribose phosphate transferase, adenine thiotransferase, adenosine phosphate sulfate kinase and polyphosphate kinase 2, a six-enzyme cascade reaction taking ribose and adenosine as substrates in vitro is constructed, the molar conversion rate reaches 22.85%, and the escherichia coli and bacillus subtilis PAPS cell factory can be used for preparing the recombinant ribose phosphate pyrophosphate kinase, the ribose phosphate transferase, the adenine thiotransferase, the adenosine phosphate sulfate kinase and the polyphosphate kinase 2. The yield of PAPS in a 5-L fermentation tank reaches 7.60 g / L and 5.03 g / L respectively. The PAPS synthesis route provided by the invention provides an extensible, economical and efficient solution for the production of sulfated compounds.

The invention relates to the field of nucleic acid fluorescence detection, in particular to a reagent and a method for detecting single-gene RNA G4 through fluorescence imaging and application of the reagent and the method. According to the invention, an RNA G4 structure targeting module and a gene sequence targeting module are adopted and are simultaneously combined to a target gene sequence and an rG4 structure in a dual-module targeting form to trigger a click chemical reaction close to triggering in a space so as to generate a nucleic acid chain of a specific sequence restored by the click chemical reaction; then, the nucleic acid sequence is used as an initiation chain, through HCR reaction, hairpins H1 and H2 are initiated to be subjected to cascade reaction, a long repeated double-chain DNA product is obtained, and fluorescence signal amplification detection can be achieved. The method has a wide application prospect.

The invention belongs to the technical field of biomedicine, and discloses a nano-particle for enhancing radioimmunotherapy effect through cascade reaction and application of the nano-particle, a preparation method of the nano-particle comprises the following steps: S1, synthesis of ZnO2; the preparation method comprises the following steps: dissolving ZnCl2 and PVP in absolute ethyl alcohol, adding ammonia water and H2O2, after the reaction is completed, collecting precipitates, washing, and dispersing the precipitates in absolute ethyl alcohol to prepare ZnO2; and S2, synthesis of ZnO2 (at) Cu: resuspending ZnO2 in water, sequentially adding ammonia water, a PAA solution, IPA, dopamine hydrochloride and a CuCl2 solution, stirring in a nitrogen atmosphere, centrifuging, washing with ethanol, and drying in vacuum to obtain the ZnO2 (at) Cu nano-particles, namely the nano-particles. According to the nanoparticles, the radiotherapy effect is enhanced through cascade reaction, copper death is induced, immune response is activated, effective treatment on tumors is achieved, and the problems of radiotherapy resistance and immunosuppressive tumor microenvironment are solved.

The invention provides a nano enzyme, a preparation method and application thereof, and a glucose concentration detection method. The Ru / Co-N and Zn-CNCs nano-material is prepared by adopting a calcination method and a reduction method, the material can quickly catalyze the oxidation reaction of TMB in the presence of hydrogen peroxide, the cascade reaction colorimetric sensor for glucose detection is successfully constructed by combining with glucose oxidase, and the preparation method is simple and convenient to operate, economical and efficient; due to the synergistic effect generated by doping of Ru metal, the nano-enzyme has better catalytic activity, meanwhile, through combination with glucose oxidase, the system can achieve ultra-sensitive colorimetric detection of glucose, excellent stability and linear response characteristics are shown, and the detection accuracy is further improved. Through colorimetric detection, the method can sensitively detect glucose in a range of 10-2000 [mu] M, and the detection limit is as low as 0.61 [mu] M.

The invention belongs to the technical field of coke oven gas purification treatment, and particularly discloses a method for removing hydrogen sulfide in coke oven gas through photocatalysis, generation of oxygen vacancies is promoted by adopting a synthesis concept of synergistic effect of silver doping and polyethyleneimine, polyethyleneimine provides an alkaline condition on one hand, lone electron pairs on nitrogen are coordinated with zinc on the other hand, and the hydrogen sulfide in the coke oven gas is removed through photocatalysis. The preparation method comprises the following steps: by taking H2S and polyethyleneimine as raw materials, generating abundant oxygen vacancies under the synergistic effect of the H2S and silver, preventing agglomeration of generated ZnO and increasing reaction sites by taking polyethyleneimine as a surfactant, and then promoting a cascade reaction between ZnO < 1-x > and H2S by taking abundant oxygen vacancies, so that a 1D / 3D-ZnS / ZnO heterojunction is generated in situ to further reduce recombination of photo-generated electron holes; the catalyst converts H2S into elemental sulfur through photo-induced electrons and holes, and a carbon disulfide solution is used for cleaning the catalyst to realize regeneration of the catalyst. The method provided by the invention not only improves the removal efficiency of H2S, but also reduces the operation cost and reduces environmental pollution.

The invention provides a method for preparing rebaudioside M by constructing a UGT91C1-UGT76G1-SuSy fusion enzyme on the basis of an artificially constructed substrate microchannel principle and using relatively cheap raw materials to efficiently catalyze a cascade reaction. EAAAK 3 and (GGGGS) 4 are used as connecting peptides, UGT76G1 is fused at the C end of UGT91C1, SuSy is fused at the C end of UGT76G1, mass transfer of an intermediate product is enhanced, and the intermediate product is prevented from being diffused to a reaction main body. The invention also discloses a construction method of the ugt91C1-C1-ugt76G1-suusy fusion gene, a construction method of a recombinant plasmid, a construction method of a recombinant strain, a protein expression and purification method and a method for catalytically preparing a product. The ugt91C1-C1-ugt76G1-suusy fusion gene has a very good application prospect in biological industrial catalytic production.

The application discloses a formic acid dehydrogenase mutant and application thereof in catalyzing carbon dioxide reduction. Paracoccus The formic acid dehydrogenase from sp.MKU1 is mutated by a site-directed mutation technology Ps The arginine (Arg) at the 223th position of the FDH48 amino acid sequence is mutated into proline (Pro) or the proline (Pro) at the 242th position is mutated into phenylalanine (Phe), and the obtained mutants R223P and P242F have higher catalytic activity, can more effectively catalyze CO2 to generate formic acid in vitro, and have potential application values in efficient activation of CO2 and further conversion into other one-carbon compounds through cascade reactions.

The present invention relates to the field of electrocatalytic reduction technology, and specifically discloses a copper-silver composite catalyst and its preparation method and application. The copper-silver composite catalyst is a core-shell structure with a copper-silver mixture as a core and copper as a shell, wherein the copper of the copper-silver mixture in the core is in a metallic state or a monovalent state, and the copper in the shell is in an oxidized state. The preparation process is to immerse an organic binuclear copper precursor and silver nanoparticles in a solvent, dry them, and then roast them. The present invention constructs a tandem reaction from the Ag active site to the Cu active site, which can effectively exert the good hydrogen evolution reaction inhibition effect of the silver-based catalyst and the superior C-C coupling performance of the copper-based catalyst. When applied to the carbon dioxide electroreduction system, it can induce the reaction to develop towards a multi-carbon product path through the copper-silver synergistic effect, and finally achieve a higher C 2+ Product selectivity.

The invention discloses a method for preparing high-value chemicals through photocatalytic driving of beta-O-4 lignin depolymerization and coupling cascade reaction, and belongs to the technical field of photocatalytic biomass resource conversion. The method comprises the following steps: (1) dispersing a beta-O-4 lignin raw material into a solvent containing a photocatalyst; (2) introducing a normal-temperature chemically stable gas to replace air in a reaction system; and (3) carrying out a depolymerization reaction of beta-O-4 bonds and an in-situ C-C bond coupling reaction under an illumination condition to generate a target product. And (4) separating and purifying the product and recovering the catalyst. Through photocatalytic cascade reaction design, the defects of harsh reaction conditions and multi-step separation in a traditional method are avoided, the method has the advantages of mild reaction conditions, high atom utilization rate, high product selectivity and environmental friendliness, and a new way is provided for high-value utilization of lignin.

The invention relates to a method for detecting miRNA (micro Ribonucleic Acid) by using a ratio-type CRISPR / Cas12a (Clustered Regularly Interspaced Short Palindromic Repeats / CRISPR / Cas12a) system. The method is characterized by being realized by applying a multifunctional probe in the CRISPR / Cas12a system. Wherein the multifunctional probe is a single-stranded DNA (deoxyribonucleic acid) with a hairpin structure and comprises two functional areas, namely a neck part and a loop part; wherein the neck part of the probe is used for identifying a target miRNA; wherein the probe ring part has various different functions of lightening a fluorescent dye, activating a CRISPR / Cas12a system, serving as a Cas12a trans-cracking substrate, triggering a self-driven cascade reaction and the like; the working principle of the method is as follows: when no target exists, the ring part of the probe cannot activate the CRISPR / Cas12a system, the G quadruplex structure of the ring part of the probe can be combined with a fluorescent dye to emit fluorescence, and the neck part of the probe is opened by combining the sticky end with the target when the target exists, so that the G quadruplex structure of the ring part of the probe disappears and releases an activator to activate the CRISPR / Cas12a system; the activated Cas12a simultaneously reversely cuts the reporter probe and the multifunctional probe around the Cas12a, so that the fluorescence of the reporter probe is enhanced and the fluorescence of the multifunctional probe is reduced, and the multifunctional probe releases more activators to trigger a self-driven cascade reaction, so that the fluorescence of the reporter probe is further enhanced and the fluorescence of the multifunctional probe is further reduced; quantitative detection of the target miRNA can be realized through the mathematical relationship between the fluorescence ratio of the report probe and the multifunctional probe and the target concentration. The ratio-type CRISPR / Cas12a system is designed according to the structure activity of DNA, the property of the fluorescent dye and the characteristics of the CRISPR / Cas12a system, sensitive detection of miRNA is achieved, and the ratio-type CRISPR / Cas12a system can be used for scientific research analysis and clinical detection and has wide market prospects.

The invention belongs to the technical field of material chemistry, and provides a light response type oxidase-like simulant with a donor-receptor structure as well as a preparation method and application of the light response type oxidase-like simulant. The oxidase-like simulant is obtained through an ammonia-aldehyde condensation reaction of 1, 3, 6, 8-tetra (4-aminophenyl) pyrene or 2, 4, 6-tri (4-aminophenyl)-1, 3, 5-triazine and BDP (1, 3, 6, 8-tetra (4-aminophenyl) pyrene. The oxidase-like enzyme can form a sensor or a kit for detecting organophosphorus pesticides together with TMB, AChE and AChE substrates; qualitative determination can be realized through visual inspection of color change, and quantitative determination can also be realized through assistance of a colorimetric instrument. The light response type nano enzyme and AChE cascade reaction can realize visual rapid detection of various organophosphorus pesticides in traditional Chinese medicinal materials such as astragalus membranaceus and angelica sinensis, and has the advantages of being simple, rapid, high in sensitivity, good in practicability and the like.

The invention belongs to the technical field of textile waste recovery, and particularly relates to a method for degrading a waste cotton-polyester blended fabric through a chemical-enzyme cascade reaction and application of the method. The invention designs a chemical-enzyme hydrolysis cascade reaction for degrading polyester-cotton blended fabrics, which comprises the following steps: firstly, using recyclable organic acid p-toluenesulfonic acid (TsOH) as a catalyst, carrying out hydrothermal treatment on the polyester-cotton blended fabrics, and hydrolyzing cotton fibers in the blended fabrics into microcrystalline cellulose; and after melting and crushing the residual polyester fibers (terylene), degrading the residual polyester fibers (terylene) into monomers terephthalic acid and ethylene glycol by using PET hydrolase. The method has very high degradation efficiency on polyester cotton mixed textiles with different proportions, does not generate secondary pollution, and provides a green way for recycling textile wastes, so that the method has good practical application value.

The invention discloses a method for preparing adipic acid through electro-catalysis of cyclohexene. The method comprises the following steps: (I) carrying out electro-catalysis reduction on oxygen at a cathode to generate hydrogen peroxide; (2) reacting hydrogen peroxide with cyclohexene to obtain cyclohexanediol; (3) carrying out electrocatalytic oxidation reaction on cyclohexanediol at an anode to obtain adipate; and (IV) acidifying, washing and drying the adipate to obtain an adipic acid solid, and the like. According to the invention, the electrochemical reaction is driven by the electric power generated by renewable energy sources, so that the cascade reaction from cyclohexene to adipic acid is realized; the preparation method is mild in condition, green and environment-friendly and high in product selectivity, cathode oxygen reduction and anode cyclohexanediol oxidation are carried out by utilizing electric power generated by renewable energy sources, hydrogen peroxide generated by a cathode reacts with cyclohexene in a flowing system to generate cyclohexanediol, reaction liquid can be directly injected into an anode for reaction, and the yield is high. In the reaction process, only oxygen, dilute alkali solution and dilute acid solution are input except for cyclohexene, so that the use of strong acid and strong oxidant is avoided.

The invention discloses 5-hydroxymethylfurfural and a preparation method thereof, and belongs to the technical field of chemical engineering. The preparation method comprises the following steps: reacting a homogeneous aqueous solution containing fructose, inorganic salt and an acid catalyst in a multi-kettle series reactor to obtain the 5-hydroxymethylfurfural, the inorganic salt is selected from at least one of halogen compounds, borides, silicate, aluminate, phosphate and borate; the acidic catalyst comprises at least one of water-soluble acids. The specific inorganic salt and the specific acid catalyst are added and can play a synergistic role, the reaction is carried out under multi-kettle series connection, the backmixing degree of the reaction materials in the reactor is maximized, side reactions can be effectively controlled, black rot is avoided, the reaction production efficiency and conversion rate are effectively improved, the reaction selectivity is improved, and the method is suitable for industrial production. And the equipment maintenance and labor cost is greatly reduced.

The invention relates to the technical field of preparation of high-added-value chemicals through chemical catalysis of catalysts, in particular to a preparation method, a product and application of a bimetallic MOF catalyst. The preparation method comprises the following steps: uniformly mixing zircon salt, tin salt, an organic ligand and an organic solvent to obtain a mixed solution; and heating the mixed solution for reaction to obtain a reaction solution, washing, carrying out solid-liquid separation, and drying the obtained solid to obtain the bimetallic MOF catalyst. The method is easy to operate and low in cost, is close to conditions of large-scale production and application, and has important practical value. The bimetallic MOF catalyst prepared by using the method disclosed by the invention enhances the Lewis acidity of the catalyst, effectively promotes isomerization conversion from xylose to xylulose and reverse aldol condensation from xylulose to a C3 intermediate product in a cascade reaction process, and improves the selectivity of a main reaction path for preparing lactic acid from biomass; and efficient catalytic conversion from biomass to lactic acid is realized.

The application discloses an emulsion microreactor for cascade reaction and a preparation method and application thereof. The emulsion microreactor is prepared by the following steps: acidolysis of agar, hydrophobic modification, mixing of obtained interface stable modified agar nanoparticles, enzymes and buffer to obtain an aqueous phase; mixing of a substrate, a catalyst and an organic solvent to obtain an oil phase; and mixing of the aqueous phase and the oil phase to obtain the emulsion microreactor. The emulsion microreactor is used for synthesizing 4-biphenylcarboxylic acid ethyl ester by using lipase and a metal palladium catalyst, solves the problem of poor compatibility between the catalyst metal palladium and the lipase, spatially separates the lipase and the metal palladium, improves the cascade catalytic efficiency of the metal enzyme, and finally the yield of the product 4-biphenylcarboxylic acid ethyl ester can reach 55.85%; and the metal enzyme cascade reaction is completed in one pot in the emulsion microreactor, avoids separation of an intermediate product, expands the range of catalytic reactions, and provides a reaction platform for other high-value-added pharmaceutical intermediate products.

The invention discloses a double-nano-enzyme composite material, a preparation method thereof and application of the double-nano-enzyme composite material in aminoglycoside antibiotic detection. The double-nano-enzyme composite material comprises an inner core and a copper-based metal organic framework material wrapping the inner core, the inner core is a mesoporous polydopamine ball loaded with Au nano particles; wherein the mesoporous polydopamine balls loaded with the Au nanoparticles are connected with the copper-based metal organic framework material through polyacrylic acid. The double-nano-enzyme composite material provided by the invention has glucose oxidase-like activity and peroxidase-like activity at the same time, can be subjected to cascade reaction, has universality on aminoglycoside antibiotic detection, has selectivity on aminoglycoside antibiotics, and can be used for detecting the aminoglycoside antibiotics. The anti-interference performance on anions and cations with the highest abundance in common organic solvents and water bodies is high, and the catalytic activity can remain 50% of the initial catalytic activity after the catalyst is recycled for 5 times.

The invention discloses a method for efficiently producing pyridoxal phosphate based on a three-enzyme cascade reaction and a recombinant strain, and belongs to the technical field of biological engineering. The recombinant escherichia coli for co-expressing the pyridoxine phosphate phosphatase mutant, the pyridoxine phosphate oxidase and the hydrogen peroxide decomposing enzyme is constructed, three-enzyme synergy is realized by optimizing the copy number of a carrier, and the catalytic efficiency of a recombinant strain as a cell catalyst is improved. The invention further provides a one-pot method for preparing pyridoxal phosphate, the production cost is reduced, an efficient, green and economical biosynthesis path is provided for industrial production of PLP, and the method can be widely applied to the fields of food, medicine and the like and has important industrial value and application prospects.

This invention discloses a method for synthesizing Rotundine and its derivatives, as well as the construction of a whole-cell catalytic system. This invention utilizes an artificially designed multi-enzyme cascade reaction method to efficiently synthesize Rotundine and its derivatives. Furthermore, this invention constructs the enzymes of the synthetic route into E. coli chassis cells to obtain a whole-cell catalyst comprising M1a, M2a, M3a, and M4a. Using the whole-cell catalyst to synthesize Rotundine and its derivatives, the yield of Rotundine can reach 2.44 g / L.

The invention discloses a preparation method of an indole-3-yl alkyl malonate compound and a preparation method of the indole-3-yl alkyl malonate compound. According to the method, reaction raw materials which are economical, cheap and easy to obtain are subjected to a three-component C (sp3)-H / C (sp2)-H functionalization reaction under a mild electrochemical condition, and the indole-3-alkyl malonate compound is obtained through one-step construction. According to the method, a C (sp3)-H / C (sp2)-H functionalization regioselective pathway is adopted, and H2 is a unique theoretical byproduct. Mechanism studies show that the reaction generates alkyl free radicals through C (sp3)-H bond oxidation, the free radicals are added to C = C bonds, and single electron oxidation and C (sp2)-H functionalization cascade reaction are carried out. Compared with an existing method, the preparation method has the outstanding advantages that the raw materials are cheap and easy to obtain, the reaction substrate is wide in application range, the target product yield is high, and the atom economy of the reaction is good.

The invention discloses a binary single-site material for controlling spatial distribution of active sites as well as a preparation method and application of the binary single-site material. The binary single-site material comprises SiO2 nanospheres, single-site metal encapsulated in the SiO2 nanospheres and single-site metal anchored on the surfaces of the SiO2 nanospheres, wherein the single-site metal includes at least one of Cu, Zr, Yb, Hf, Y, and Zn. The preparation method adopting a reverse microemulsion method has universality, a high-dispersion single-site catalyst of corresponding metal can be synthesized by changing the variety of coated organic metal salt, the problem that high-dispersion single-metal sites cannot be synthesized in a SiO2 bulk phase is solved, spatial distribution of active sites can be accurately controlled, and the preparation method is suitable for large-scale industrial production. And the catalyst inhibits the generation of a by-product ethylene, significantly improves the catalytic activity and butene selectivity through an ordered catalytic cascade reaction, and can better meet the field of ethanol-to-olefin catalysis.

A fluidized bed device for coupling naphtha and methanol to prepare aromatics and co-produce olefins and its application method are provided. By using the device, under the action of a catalyst, naphtha reacts with methanol to generate product gas containing aromatics and light olefins as main components. The method can efficiently and selectively convert linear and branched aliphatic hydrocarbons into aromatics, while also increasing p-xylene production through aromatic methylation reactions, with the p-xylene content in the xylene mixture exceeding 75 wt %. The fluidized bed reactor achieves increased p-xylene production by controlling the progression of cascade reactions (naphtha→benzene / toluene→p-xylene). Additionally, it utilizes the methylation reaction of benzene / toluene with methanol to provide in-situ heat for the coupled naphtha-methanol aromatization process, thereby achieving autothermal balance.

This invention discloses a method for preparing sulfonamide-modified benzo[a]fluorene-5-one derivatives, using 1,7-enyne and N Using sulfonylaminopyridine salts as raw materials, a series of sulfonated benzo[a]fluorene-5-one compounds were successfully synthesized by catalyzing the sulfonation / cyclization tandem reaction of 1,7-enynes under photocatalytic conditions. This method has excellent functional group tolerance and high economic applicability.

The present application relates to the technical field of organic synthesis, and particularly relates to a method for preparing (+)-crispine A by means of biological enzyme resolution. First, 6,7-dimethoxy-3,4-dihydroisoquinoline-2-oxide is subjected to 1,3-dipolar cycloaddition with allyl alcohol to obtain a first compound; then the first compound is added into a sulfonylation reagent and zinc powder to obtain a racemate second compound through a three-step continuous series reaction of primary alcohol sulfonylation, nitrogen-oxygen bond cleavage and ring formation; then the second compound is mixed with vinyl acetate and biological enzyme, and chiral resolution is carried out under the action of the biological enzyme to obtain a third compound with right-handed optical rotation and a fourth compound with left-handed optical rotation; finally, the third compound is mixed with an alkaline reagent and a sulfonylation reagent, and then secondary alcohol sulfonylation is carried out to obtain a fifth compound with right-handed optical rotation; the fifth compound is mixed with a deoxidizing reagent to carry out deoxidation reaction, and (+)-crispine A is prepared. The method is simple, green and environmentally friendly, and can be produced in large quantities.

The present invention discloses a method for biocatalytic conversion of β-ionol to prepare dihydro-β-ionone, belonging to the technical field of bioengineering. In the present invention, β-ionol is used as a substrate, and short-chain alcohol dehydrogenase NaSDR and enoate reductase AaDBR1 are added for reaction. The reaction temperature is 25-60 °C, the pH is 4.0-11.0, and the reaction time is 0.5-3 h to obtain β-ionone. The present invention uses short-chain alcohol dehydrogenase and enoate reductase for cascade reaction, establishes a process for in vitro one-pot biopreparation of dihydro-β-ionone using β-ionol as a substrate, and realizes the regeneration and self-circulation of NADPH, thus creating a new method for highly efficient and low-cost biosynthesis of dihydro-β-ionone.

The invention discloses an antibacterial peptide modified bionic nanoparticle targeting delivery system as well as a construction method and application thereof. The antibacterial peptide modified bionic nanoparticle targeting delivery system comprises a recombinant antibacterial peptide LL-37, a macrophage membrane and an enzyme cascade reaction system, the recombinant antibacterial peptide LL-37 is expressed on the macrophage cell membrane to form a macrophage cell membrane modified by the recombinant antibacterial peptide LL-37; the enzyme cascade reaction system is wrapped by the macrophage membrane modified by the recombinant antibacterial peptide LL-37, so that the bionic nanoparticle targeted delivery system modified by the antibacterial peptide is formed; wherein a Toll-like receptor 2 and a Toll-like receptor 4 are highly expressed on the surface of a macrophage cell membrane; the enzyme cascade reaction system comprises a nano enzyme with catalase-like activity and a hydrogen peroxide-producing biological enzyme. The antibacterial peptide modified bionic nanoparticle targeting delivery system disclosed by the invention can be used for treating infectious bone defects such as periodontitis, peri-implantitis, infectious fracture, osteomyelitis and the like.