Abstract: An object is to provide a crystal of anagliptin, which has a high purity and is excellent in stability, low in hygroscopicity, and has a characteristic of easily dissolving into water, and a method for producing the crystal. An anagliptin crystal showing a powder X-ray diffraction pattern substantially the same as in FIG. 1, which has peaks around at 9.8°, 17.4°, 18.6°, 25.3°, and 25.8° as diffraction angles represented by 2?. The crystal is obtained by reacting N-(2-amino-2-methylpropyl)-2-methylpyrazolo[1,5-a]pyrimidine-6-carboxamide and (2S)—N-chloroacetyl-2-cyanopyrrolidine in an organic solvent, thereafter purifying the reaction solution by column chromatography to thus obtain an amorphia of anagliptin, and crystallizing the amorphia of anagliptin from 2-propanol.

Abstract: The present invention aims at providing a peptide fragment capable of improving biostability of a bioactive substance while maintaining the activity of the bioactive substance, and a bioactive substance to which the peptide fragment is added. The present invention relates to a partial peptide of a GA module having 5 to 25 amino acids, including a partial sequence of a GA module (SEQ ID NO: 1) and the amino acid sequence Ile-Asp-Glu-Ile-Leu (SEQ ID NO: 2), and a bioactive complex in which the partial peptide of the GA module is bound to a bioactive substance. The bioactive substance includes GLP-1, GLP-2, GIP, VIP, somatostatin, amylin, ghrelin, derivatives thereof, and the like.

Abstract: A dipeptidyl peptidase IV inhibitor which is satisfactory in respect of activity, stability and safety and has an excellent action as a pharmaceutical agent. A compound represented by the following general formula or a pharmaceutically acceptable salt thereof: wherein R1 and R2 each represents hydrogen, an optionally substituted C1-6 alkyl group, or —COOR5 whereupon R5 represents hydrogen or an optionally substituted C1-6 alkyl group, or R1, R2, and a carbon atom together represent a 3- to 6-membered cycloalkyl group, R3 represents hydrogen or an optionally substituted C6-10 aryl group, R4represents a hydrogen or a cyano group, D represents —CONR6-, —CO— or —NR6CO—, R6 represents hydrogen or an optionally substituted C1-6 alkyl group, E represents —(CH2)m— whereupon m is 1 to 3, —CH2OCH2—, or —SCH2—, n is 0 to 3, and A represents an optionally substituted bicyclic heterocyclic group or bicyclic hydrocarbon group.

Abstract: A dipeptidyl peptidase IV inhibitor which is satisfactory in respect of activity, stability and safety and has an excellent action as a pharmaceutical agent. A compound represented by the following general formula or a pharmaceutically acceptable salt thereof: wherein R1 and R2 each represents hydrogen, an optionally substituted C1-6 alkyl group, or —COOR5 whereupon R5 represents hydrogen or an optionally substituted C1-6 alkyl group, or R1, R2, and a carbon atom together represent a 3- to 6-membered cycloalkyl group, R3 represents hydrogen or an optionally substituted C6-10 aryl group, R4 represents a hydrogen or a cyano group, D represents —CONR6—, —CO— or —NR6CO—, R6 represents hydrogen or an optionally substituted C1-6 alkyl group, E represents —(CH2)m— whereupon m is 1 to 3, —CH2OCH2—, or —SCH2—, n is 0 to 3, and A represents an optionally substituted bicyclic heterocyclic group or bicyclic hydrocarbon group.