Highly site-specific oxygenation of 1-methylhistidine and its analogue with a copper(II)/ascorbate-dependent redox system

• Published in: Biochimica et biophysica acta Vol. 1034; no. 3; pp. 347 - 350
• Main Authors: Uchida, Koji, Kawakishi, Shunro
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 20.06.1990; Elsevier; North-Holland
• Subjects: 1-Methylhistidine; Acetylation; Anserine; Ascorbate; Ascorbic Acid; Biological and medical sciences; Cell metabolism, cell oxidation; Cell physiology; Chromatography, High Pressure Liquid; Copper; Copper(II) ion; Fundamental and applied biological sciences. Psychology; Histidine - analogs & derivatives; Magnetic Resonance Spectroscopy; Mass Spectrometry; Methylhistidines; Molecular and cellular biology; Molecular Structure; Oxidation-Reduction; Oxygenation; Ascorbate; 1-Methylhistidine; Oxygenation; Copper(II) ion; Anserine; Reaction intermediate; Specificity; Ascorbic acid; HPLC chromatography; Reaction mechanism; Copper; Mass spectrometry; Ultraviolet visible spectrometry
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/0304-4165(90)90063-3

The reaction of histidine-related materials with copper(II) and ascorbate under physiological conditions has been studied chemically. We discovered that 1-methylimidazole and its analogues, including biological metaboliets l-1-methylhistidine and anserine (β-alanyl- l-methylhistidine), exhibited dramatic reactivity with copper(II)/ascorbate. Reaction of copper(II) and ascorbate occurs specifically at the C-2 position of the imidazole ring of l-1-methylhistidine and anserine derivatives with mono-oxygenation to give the 1-methyl-2-imidazolones in good to excellent yields (70–80%). The occurrence of an oxocopper(III) intermediate in the oxidation process of ascorbate is postulated.