4257-92-5

Basic information

• Product Name: histidyl-proline diketopiperazine
• Synonyms: Cyclo(histidyl-prolyl);His-Pro-dkp;Pyrrolo(1,2-A)pyrazine-1,4-dione, hexahydro-3-(1H-imidazol-4-ylmethyl)-, (3S-trans)-
• CAS NO: 4257-92-5
• Molecular Formula: C12H16N4O2
• Molecular Weight: 234.25
• Mol File: 4257-92-5.mol
• Article Data: 1

Chemical Properties

• Boiling Point: 650.3°Cat760mmHg
• Flash Point: 347.1°C
• Appearance: /
• Density: 1.36g/cm³
• CAS DataBase Reference: histidyl-proline diketopiperazine(CAS DataBase Reference)
• NIST Chemistry Reference: histidyl-proline diketopiperazine(4257-92-5)
• EPA Substance Registry System: histidyl-proline diketopiperazine(4257-92-5)

Safety Data

• Hazardous Substances Data: 4257-92-5(Hazardous Substances Data)

Upstream product

• 33605-69-5 L-histydyl-L-prolineamide 

Relevant articles and documents

Kinetics and Mechanism of the Facile Cyclization of Histidyl-prolineamide to Cyclo (His-Pro) in Aqueous Solution and the Competitive Influence of Human Plasma

A crucial point in the biosynthesis of cyclo (His-Pro), an endogenous and biologically active cyclic dipeptide, is the spontaneous cyclization of its precursor L-histidyl-L-prolineamide (His-ProNH2).In this study the kinetics and mechanism of the cyclization process has been investigated.His-ProNH2 was found to be converted quantitatively to cyclo(His-Pro) in aqueous solution at pH 2-10 and 37degC, the rate of cyclization being maximal at pH 6-7.Buffer substances such as phosphate (pH 6-7.4) were found to catalyse the cyclization.The bell-shaped pH-rate profile observed was accounted for by assuming spontaneous and specific acid- and base-catalysed reactions of the His-ProNH2 species in which the imidazole group is protonated and the primary amino group unprotonated.The much more rapid rate of cyclization of His-ProNH2 (t1/2 of 140 min at pH 6-7 and 37degC) relative to other proline-containing di- and tripeptides studied was suggested to be due to an intramolecular general acid catalytic effect by the protonated imidazole group.In the presence of human plasma enzymatic hydrolysis of His-ProNH2 competed with the cyclization and predominated greatly at 80percent plasma concentration.