Provided in the present invention is a preparation method for a siRNA for inhibiting PCSK9 gene expression. The siRNA in the preparation method is a double-stranded RNA consisting of a sense strand and an antisense strand which are complementarily paired. The preparation method comprises: mixing a sense strand substrate, an antisense strand substrate and an RNA ligase, using the RNA ligase for catalyzing the sense strand substrate and the antisense strand substrate to be connected by means of a phosphodiester bond, and obtaining a sense strand and an antisense strand, so as to obtain the siRNA. The sense strand substrate can form the sense strand, and the antisense strand substrate can form the antisense strand. The sense strand is a nucleic acid sequence as shown in SEQ ID NO: 45, and the antisense strand is a nucleic acid sequence as shown as SEQ ID NO: 46. The solution solves the problem in the prior art of low purity of the siRNA, and is applicable in the field of medicine biosynthesis.
Provided in the present invention are a purine nucleoside phosphorylase mutant and a preparation method for 2'-fluoro nucleoside. The purine nucleoside phosphorylase mutant comprises: (a) a mutant protein generated on the basis of a purine nucleoside phosphorylase wild-type enzyme GsPNP as shown in SEQ ID NO: 3, the mutation being selected from any one or more of the following mutations: L148, P19, Q41, etc.; or (b) a protein having 70% or more homology with the amino acid sequence defined in (a) and having purine nucleoside phosphorylase activity. The method can solve the problem in the prior art of low yield of 2'-fluoro nucleoside synthesized by enzyme catalysis, and is suitable for the field of enzyme catalysis.
Provided in the present invention are a pyrimidine nucleoside phosphorylase mutant and a preparation method for 2'-fluoro nucleoside. The pyrimidine nucleoside phosphorylase mutant comprises: (a) a mutant protein generated on the basis of a pyrimidine nucleoside phosphorylase wild-type enzyme TtPyNP as shown in SEQ ID NO: 1, the mutation being selected from any one or more of of the following mutations: K80 etc.; or (b) a protein having 70% or more homology with the amino acid sequence defined in (a) and having purine nucleoside phosphorylase activity. The method can solve the problem in the prior art of low yield of 2'-fluoro nucleoside synthesized by enzyme catalysis, and is suitable for the field of enzyme catalysis.
A method for preparing a hydrazine compound. The method comprises: using an imine reductase to catalyze a reduction reaction between a substrate ketone compound as shown in formula I or formula III and a substrate hydrazine compound as shown in formula II, to obtain a product hydrazine compound. The imine reductase is used to perform the synthesis of the hydrazine compound, the synthesis process is simple and economical, various hydrazine compounds can be directly synthesized, and fewer substituent groups are present on the N atoms of the resulting hydrazine compounds. In addition, the method can be used for industrial amplification, is low in cost and high in purity, and achieves true green chemistry.
The disclosure provides a new crystal form of ertapenem sodium and preparation method therefor. The new crystal form of ertapenem sodium has 27 principal characteristic peaks in an X-ray powder diffraction diagram. The crystal form of ertapenem sodium of the disclosure has a rod-like crystal habit, which has a large particle size, is not prone to aggregation and is easier to dry, and a product with high crystallinity and high purity may be obtained by simple drying treatment. Meanwhile, the crystal form of the disclosure has better stability, and the crystal form may remain unchanged to a maximum extent in subsequent washing and drying processes, thereby further improving the purity of the product.
C07D 477/06 - Préparation à partir de composés contenant déjà les systèmes cycliques ou cycliques condensés, p. ex. par déshydrogénation du cycle, par introduction, élimination ou modification de substituants
6.
NEW CRYSTALLINE FORM OF ERTAPENEM SODIUM AND PREPARATION METHOD THEREFOR
Provided are a new crystalline form of ertapenem sodium and a preparation method therefor. The powder X-ray diffraction diagram of the new crystalline form of ertapenem sodium contains 27 principal characteristic peaks. The ertapenem sodium of the present invention has a rod-like crystalline form with a large particle size, does not easily aggregate and is easier to dry out. Products having high crystallinity and purity may be obtained by a simple drying process. Furthermore, the new crystalline form of the present invention is more stable, and the crystalline form may remain unchanged to a maximum extent during a subsequent washing and drying process, so that the purity of the product may be further improved. In addition, since the new crystalline form of ertapenem sodium of the present invention has a relatively large particle size and good stability, it is easier to produce on a factory scale, so that it is possible to obtain ertapenem sodium products with a high purity and a high yield.
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:
10 and benzyl.
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.
C07F 9/6561 - Composés hétérocycliques, p. ex. contenant du phosphore comme hétéro-atome du cycle contenant des systèmes de plusieurs hétérocycles déterminants condensés entre eux ou condensés avec un carbocycle ou un système carbocyclique commun, avec ou sans autres hétérocycles non condensés
B01J 8/02 - Procédés chimiques ou physiques en général, conduits en présence de fluides et de particules solidesAppareillage pour de tels procédés avec des particules immobiles, p. ex. dans des lits fixes
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