Abstract: The invention relates to a low molecular weight sulfate chondroitin and a preparation method thereof. A low molecular weight chondroitin sulfate with the average molecular weight of less than 1000 Dalton can be obtained by a production process of chondroitin sulfate lyase degradation, deproteinization, filtration and sterilization and drying using macromolecular sulfate chondroitin as a raw material. The low molecular weight Chondroitin sulfate has a narrow molecular weight distribution range, the ratio of chondroitin sulfate disaccharide is 43˜60% and the ratio of chondroitin sulfate tetrasaccharide is 30˜45%, the sum of chondroitin sulfate disaccharide and chondroitin sulfate tetrasaccharide is more than 87%, the total oligosaccharide content of low molecular weight chondroitin sulfate is more than 97% and the protein content is less than 0.

Abstract: The invention belongs to the technical field of polypeptide preparation methods, and in particular relates to a high-purity ACTH (human sequence) or analogue and large-scale preparation method thereof. The main steps include: amino acids are coupled from the C-terminal to the N-terminal by Fmoc solid-phase synthesis method to obtain the crude ACTH (human sequence) or analogue peptidyl-resin with protective groups, wherein the reaction temperature of C-15 peptide synthesis is 40-60° C. After cleavge and precipitation, the crude product of ACTH (human sequence) or analogue is obtained, and then the high-purity product is obtained by liquid chromatography. The chromatographic purity of ACTH (human sequence) or analogue prepared by the invention is more than 99%, the stability is good, and the yield of the target peptide is ?63%.