title: Characterization of crystalline L-carnosine Zn(II) complex (Z-103), a novel anti-gastric ulcer agent: tautomeric change of imidazole moiety upon complexation.
abstract: A novel crystalline Zn(II) complex of L-carnosine was prepared and evaluated for inhibitory activity against gastric ulceration in rats. The complex was found to be much more active than various other Zn(II) compounds. It was characterized by means of infrared (IR) spectroscopy, solid-state carbon-13 (13C) and nitrogen-15 (15N) 1H-cross-polarization (CP) magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The spectroscopic data indicated that L-carnosine coordinates to Zn(II) as a quadridentate ligand. A comparison of the 13C-NMR signals of the imidazole carbons of the complex with those of several histidine derivatives revealed that a tautomeric change of imidazole moiety had occurred upon complexation. The binding mode of the complex was considered to be analogous to that of the corresponding Cu(II) complex.
authors.affiliation: Research Laboratories, Hamari Chemicals Ltd., Osaka, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Matsukura
authors.forename: T
authors.initials: T
authors.lastname: Takahashi
authors.forename: Y
authors.initials: Y
authors.lastname: Nishimura
authors.forename: T
authors.initials: T
authors.lastname: Ohtani
authors.forename: M
authors.initials: M
authors.lastname: Sawada
authors.forename: K
authors.initials: K
authors.lastname: Shibata
mesh_terms: D000818:Animals; D000897:Anti-Ulcer Agents / Q000737:chemistry*; D002336:Carnosine / Q000031:analogs & derivatives*; D004151:Dipeptides / Q000737:chemistry* / Q000494:pharmacology; D007093:Imidazoles / Q000737:chemistry*; D007536:Isomerism; D009942:Organometallic Compounds / Q000737:chemistry* / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D017967:Zinc Compounds
chemical_list: D000897:Anti-Ulcer Agents; D004151:Dipeptides; D007093:Imidazoles; D009942:Organometallic Compounds; D017967:Zinc Compounds; C061957:polaprezinc; D002336:Carnosine