Abstract: A transaminase mutant and use hereof, the amino acid sequence of the transaminase mutant is an amino acid sequence in which the amino acid sequence as represented by SEQ ID NO: 1 is mutated, the mutated amino acid position being one or more selected from among F89, K193, P243, V234, I262, Q280, V379, R416, A417 and C418. The enzymatic activity and/or stability of the transaminase mutant is improved.

Abstract: Disclosed is a method for continuously synthesizing a propellane compound. The method includes the following steps: using 1,1-dibromo-2,2-bis(chloromethyl)cyclopropane or a derivative thereof as a raw material to form a ring with a lithium metal agent by a continuous reaction, so as to synthesize the propellane compound. A technical scheme of the present disclosure is applied, and a continuous reaction device is used.

Abstract: Provided are a proline hydroxylase and uses thereof. The proline hydroxylase comprises having the amino acid sequence of SEQ ID NO: 2 with the exception of a mutation of one or more amino acids; wherein the mutation of one or more amino acids must comprises E27K, and the mutation of one or more amino acids selected from the group consisting of: H14R, L16N, T25R, F26L, E27K, D30S, S33N, E34N, E34G, E34L, E34S, E34D, Y35W, Y35K, S37W, S37F, S37E, S37N, S37T, S37C, W40F, K41E, D54G, H55Q, S57L, I58T, I58Y, I58A, I58R, I58V, I58S, I58C, K86P, T91A, F95Y, C97Y, I98V, K106V, K106T, K106Q, F111S, K112E, K112R, S154A, K162E, L166M, I118F, I118V, I118R, H119R, H119F, I120V, K123D, K123N, K123Q, K123S, K123I, K123T, T130N, D134G, V135K, N165H, D173G, K209R, I223V and S225A, and having proline hydroxylase activity.

Abstract: The present application relates to the technical field of genetic engineering, and provides a monooxygenase mutant, a preparation method and application thereof. The monooxygenase mutant has any one of the amino acid sequences shown in (I) and (II): (I) an amino acid sequence having at least 80% identity with the amino acid sequence shown in SEQ ID NO. 1; and (II) an amino acid sequence obtained by modifying, substituting, deleting, or adding one or several amino acids to the amino acids at 23 to 508 positions of the amino acid sequence shown in SEQ ID NO. 1, the substituting referring to a substitution of 1 to 34 amino acids, wherein the mutant has the activity of monooxygenase.

Abstract: Provided is an amino acid dehydrogenase mutant. The amino acid sequence of the mutant is obtained by mutating the amino acid sequence shown in SEQ ID NO:1. The mutation includes at least one of the following mutation sites: 64th, 94th, 133rd, 137th, 148th, 168th, 173rd, 183 rd, 191st, 207th, 229th, 248th, 255th and 282nd sites; or the amino acid sequence of the amino acid dehydrogenase mutant is an amino acid sequence having the mutation sites in the mutated amino acid sequence and having a 80% or more homology with the mutated amino acid sequence. The mutant enzyme activity is more than 50 times higher than that of wild amino acid dehydrogenase, and the enzyme specificity is also correspondingly improved.

Abstract: A preparation method for a trans-cyclobutane-o-dicarboxylic acid ester and a derivative thereof includes the following steps: in an organic solvent, catalyzing a substrate with a structure as shown in a structural formula I by using organic alkali at 50-90° C. so as to generate isomerization, acquiring the trans-cyclobutane-o-dicarboxylic acid ester or the derivative thereof, herein the structural formula I is as follows: Each R1, R2, R3 and R4 is independently one of hydrogen or an alkyl of C1-C5, and each of R5 and R6 is independently one of alkyl of C1-C10 and benzyl.

Abstract: The disclosure discloses a method for an addition reaction of acetylene and a ketone compound. The method includes the following steps: S1, providing a continuous reaction device, wherein the continuous reaction device includes a plurality of bubble tubular reactors being connected with each other through connecting tubes; feeding a raw material solution containing the ketone compound and alkali into the plurality of bubble tubular reactors, and S3, under normal pressure, pumping acetylene from the bottom of the first bubble tubular reactor for the addition reaction. By applying the technical solution of the invention, acetylene reacts with the ketone compound in the plurality of bubble tubular reactors arranged in series, which can ensure the sufficient gas-liquid contact time, and thus making full use of the acetylene gas, improving the utilization rate thereof, effectively reduing the amount of acetylene, reducing costs, and further improving the safety.

Abstract: Disclosed is a method for continuously synthesizing a propellane compound. The method includes the following steps: using 1,1-dibromo-2,2-bis(chloromethyl)cyclopropane or a derivative thereof as a raw material to form a ring with a lithium metal agent by a continuous reaction, so as to synthesize the propellane compound. A technical scheme of the present disclosure is applied, and a continuous reaction device is used.

Abstract: Provided is a continuous synthesis method for ethoxymethylenemalononitrile. The method includes the following steps: malononitrile, triethyl orthoformate and acetic anhydride are continuously fed into a continuous reaction device to perform a condensation reaction, to obtain the ethoxymethylenemalononitrile, and in the process of the condensation reaction, the generated ethoxymethylenemalononitrile is continuously discharged; herein, the molar ratio of the malononitrile, the triethyl orthoformate and the acetic anhydride is 1:(0.9-6.0):(2.0-6.0). By adopting the continuous reaction device in the present disclosure, since the amount of materials involved in the reaction per unit time is greatly reduced, a high temperature dangerous area is reduced, and a safety risk is greatly reduced.

Abstract: The application provides a continuous preparation method for benzylzinc halide and a derivative thereof.

Abstract: The present disclosure discloses a continuous preparation method for a penem intermediate MAP. The continuous preparation method includes the following steps: step S1, in a column-type continuous reactor, using a rhodium-loaded catalyst to catalyze 4-nitrobenzyl(R)-2-diazo-4-((2R,3S)-3-((R)-1-hydroxyethyl)-4-oxoazetidin-2-yl)-3-oxopentanoate to generate a cyclization reaction so as to form a first intermediate, herein the rhodium-loaded catalyst is loaded in the column-type continuous reactor, and the rhodium-loaded catalyst has the following structural formula: step S2, performing an esterification reaction on the first intermediate, a diphenyl chlorophosphate and a diisopropylethylamine in a second continuous reactor, to obtain a product system containing the penem intermediate MAP; and step S3, performing crystallization treatment on the product system, to obtain the penem intermediate MAP.

Abstract: The present disclosure provides a device for continuously preparing 2,6-dihydroxybenzaldehyde and use thereof. The device includes a first continuous reaction unit for hydroxy protection reaction, a second continuous reaction unit for lithiation and hydroformylation, and a third continuous reaction unit for deprotection reaction that are connected in series. The third continuous reaction unit includes: a first columnar continuous reactor, connected to the second continuous reaction unit and used for deprotection of the lithiated hydroformylated product while performing liquid separation to obtain an organic phase containing 2,6-dihydroxybenzaldehyde and an aqueous phase. When the device is applied in the preparation of 2,6-dihydroxybenzaldehyde, reaction time is shortened and the intermediate purification treatment is no longer required.

Abstract: Disclosed are a borohydride reduction stabilizing system and a method for reducing an ester to an alcohol. The borohydride reduction stabilizing system includes: a borohydride reducing agent and a stabilizing agent for stabilizing the borohydride reducing agent. The borohydride reducing agent is sodium borohydride or potassium borohydride. The stabilizing agent is an alkali metal salt of an alcohol. By adding the alkali metal salt of the alcohol, such as sodium alkoxide or potassium alkoxide, on the basis of an existing sodium/potassium borohydride reducing agent, the sodium/potassium borohydride reducing agent may be kept stable without being decomposed under the condition of increased temperature, so that on the one hand, the reducing activity is maintained in a relatively high state, and the condition of excessive use is reduced, and on the other hand, the generation of hydrogen is reduced, and the process risks are reduced.

Abstract: The present disclosure provides a preparation method for metformin hydrochloride. The preparation method includes: microwave heating raw materials containing dicyandiamide and dimethylamine hydrochloride, and reacting the two at 100° C. to 160° C. to obtain a product system containing metformin hydrochloride. Microwave heating is adopted to heat the dicyandiamide and the dimethylamine hydrochloride. Compared with a conventional heating mode that requires heat to be gradually transferred from the outside to the inside, microwave heating can directly heat each part inside the reactant, which can make the internal temperature of the reactant more uniform, thereby reducing the generation of impurities.

Abstract: Disclosed are transaminase mutants and use thereof. The amino acid sequence of the transaminase mutant is obtained by the mutation of the amino acid sequence as shown in SEQ ID NO: 1, and the mutation at least comprises one of the following mutation sites: the 19-th site, the 41-th site, the 43-th site, the 72-th site, the 76-th site, the 92-th site, the 107-th site, the 125-th site, the 132-th site, the 226-th site, the 292-th site, the 295-th site, the 308-th site, and the 332-th site; and the 19-th site is mutated into a serine, the 41-th site is mutated into a serine, the 43-th site is mutated into an asparagine, a glycine in the 72-th site is mutated into a leucine, etc.; or the amino acid sequence of the transaminase mutant has the mutation sites in the mutanted amino acid sequence, and has more than 80% homology to the mutanted amino acid sequence.

Abstract: Provided is a preparation process of diazomethane. The preparation process includes: step S1, taking N-methylurea as a raw material to continuously prepare, in a continuous reactor, a first product system containing N-methyl-N-nitrosourea; step S2, performing continuous extraction and continuous back-extraction on the first product system to obtain an N-methyl-N-nitrosourea solution; step S3, enabling the N-methyl-N-nitrosourea solution to continuously react with an alkaline solution in a continuous reactor to obtain a second product system containing the diazomethane; and step S4, performing continuously liquid separation, water freezing and removal on the second product system, to obtain the diazomethane.

Abstract: The present disclosure discloses a method and a device for continuously synthesizing cyclopropane compounds. The method includes the following steps: continuously performing a synthetic reaction of a diazomethane precursor in a first reactor, the reaction product of the first reactor flowing into a separator for stratification, the organic phase obtained by stratification overflowing into a second reactor, continuously consuming the diazomethane precursor in a second reactor to prepare diazomethane and performing an electron-rich monoolefin cyclopropanation reaction in situ so as to obtain the cyclopropane compound. The technical solution of the present disclosure may be applied to achieve automatic control, decrease the transfer of high-risk materials, and prevent the risk of pipeline transfer of diazomethane solution, and effectively improve production safety.

Abstract: The invention provides a transaminase mutant and application thereof, wherein the amino acid sequence of the transaminase mutant is formed after mutation of the amino acid sequence as shown in SEQ ID NO: 1, and mutated amino acid sites comprise T7C+S47C sites. The transaminase mutant having the mutation sites can be further prepared into an immobilized enzyme through an immobilization technology, the immobilized enzyme has relatively high activity and high stability, can be recycled for multiple times, and is applicable to continuous flow reaction in a packed bed.

Abstract: Provided is a continuous synthesis method for 1,1?-bicyclic[1.1.1]pentane-1,3-diethyl ketone compounds. The continuous synthesis method comprises: under the irradiation of a light source, continuously conveying raw material A and raw material B to a continuous reaction device for a continuous photochemical reaction to obtain 1,1?-bicyclic[1.1.1]pentane-1,3-diethyl ketone compounds, and controlling the reaction temperature in the continuous reaction device by a temperature control device during the continuous photochemical reaction. A propellane with substituents, as a reaction raw material, is subjected to the above photochemical reaction in the continuous reaction device to reduce the probability of its slow decomposition and deterioration under the irradiation, and greatly improve the conversion rate of the reaction material and product yield.

Abstract: Disclosed are a monooxygenase mutant and use thereof. An amino acid sequence of a monooxygenase mutant is an amino acid sequence obtained by mutating an amino acid sequence as shown in SEQ ID NO: 1. Mutation includes at least one of the following mutation sites: site 49, site 60, site 61, site 144, site 145, site 146, site 147, site 167, site 169, site 189, site 246, site 247, site 280, site 284, site 285, site 286, site 287, site 328, site 330, site 332, site 382, site 427, site 428, site 429, site 430, site 431, site 432, site 433, site 434, site 435, site 436, site 438, site 441, site 493, site 494, site 508, site 509, site 510, site 511, site 512, and site 513 sites and the like. The monooxygenase mutant has the advantage of greatly improved stereoselectivity, and the enzyme activity is also improved correspondingly.