Abstract: The invention belongs to the technical field of polypeptide preparation methods, and in particular relates to a preparation method of a liraglutide intermediate polypeptide GLP-1 (7-37). In the preparation method, main steps include constructing recombinant liraglutide engineered bacteria via E. coli to induce expression of a liraglutide intermediate fusion protein in the form of inclusion bodies, and performing denaturation, renaturation, enzyme digestion, separation and purification to obtain the liraglutide intermediate polypeptide GLP-1 (7-37). The invention alters expression pattern into the expression of the intracellular insoluble inclusion bodies by changing a signal peptide of the recombinant sequence to increase significantly expression level. The liraglutide intermediate polypeptide prepared by the invention has a purity up to 87% or more and a yield of more than 85%.

Abstract: Disclosed is a preparation method for a racemic adrenaline as represented by formula II. The method comprises the following steps: compound 1 is directly racemized in an acidic solution to produce compound 2, the acid solution comprising neither sodium bisulfite nor salicylic acid; and specifically comprises (a), in the acid solution of which the pH is 0.5-1.5, compound 1 is placed under the protection of nitrogen gas and, with the reaction temperature being controlled at 75-95° C., stirred and reacted for 1-3 hours; (b) the reaction solution is controlled at a temperature of 5-20° C., into which an activated carbon is added, under the protection of nitrogen gas, stirred for 20-40 minutes, and filtered, then a filtrate is collected; the filtrate is controlled at a temperature of 5-20° C., the pH thereof is adjusted using ammonia to 8.5-9.5, and is filtered when the pH is stabilized, and a filter cake is washed and dried to produce a high purity racemic adrenaline white powder.

Abstract: The invention belongs to the technical field of polypeptide preparation methods, and in particular relates to a preparation method of a liraglutide intermediate polypeptide GLP-1 (7-37). In the preparation method, main steps include constructing recombinant liraglutide engineered bacteria via E. coli to induce expression of a liraglutide intermediate fusion protein in the form of inclusion bodies, and performing denaturation, renaturation, enzyme digestion, separation and purification to obtain the liraglutide intermediate polypeptide GLP-1 (7-37). The invention alters expression pattern into the expression of the intracellular insoluble inclusion bodies by changing a signal peptide of the recombinant sequence to increase significantly expression level. The liraglutide intermediate polypeptide prepared by the invention has a purity up to 87% or more and a yield of more than 85%.