Creatinine complexes of zinc, cadmium and mercury

Fluorescence-based assay for reactive oxygen species: a protective role for creatinine.

Abstract: Attack by reactive oxygen species leads to a decay in phycoerythrin fluorescence emission. This phenomenon provides a versatile new assay for small molecules and macromolecules that can function as protective compounds. With 1-2 x 10(-8) M phycoerythrin, under conditions where peroxyl radical generation is rate-limiting, the fluorescence decay follows apparent zero-order kinetics. On reaction with HO., generated with the ascorbate-Cu2+ system, the fluorescence decays with apparent first-order kinetics. Examination of the major components of human urine in this assay confirms that at physiological concentrations, urate protects against both types of oxygen radicals. A novel finding is that creatinine protects efficiently by a chelation mechanism against radical damage in the ascorbate-Cu2+ system at creatinine, ascorbate, and Cu2+ concentrations comparable to those in normal urine. Urate and creatinine provide complementary modes of protection against reactive oxygen species in the urinary tract.

Coordination properties of the bioligands creatinine and creatine in various reaction media

Abstract: Data on the ability of the important bioligands creatinine and creatine to form various types of complexes with different metal ions are summarized. The crucial role of the nature of the reaction medium in complex formation with these ligands is emphasized. The conditions for obtaining paramagnetic oligomeric platinum complexes of the “platinum blue” type (resulting from multistep redox and coordination processes) are presented.

Monomeric Pt(II) and Pd(II) complexes with Creatinine. Crystal structure of tetrakis-(Creatinine) platinum(II) diperchlorate

Abstract: Pt(II) and Pd(II) complexes with creatinine, C3H2N2(O)(CH3)NH2, were synthesized. Potentiometric and IR spectroscopic analyses were carried out. A model for the coordination of the ligands to the central atoms was confirmed by X-ray structural investigation of Pt(creat)4(ClO4)2. The compound [Pt(C4H7N3O)(ClO4)2] crystallizes in the monoclinic crystal system, space group C2/c, a = 15.748(5), b = 15.763(7), c = 24.843(8) A, β = 106.84(4)°, V = 5902 A3, Z = 8. The refinement of the structure by the least-squares method gave R = 0.051 and Rw = 0.054 for 1527 observed reflections with I > 2σ(I). The structure consists of Pt(creat)42+ complex cations, possessing approximate D2 symmetry and rotationally disordered perchlorate anions. The Pt atom is square-planarly coordinated by the endocyclic N atoms of four creatinine ligands. The PtN bond lengths range from 2.00(2) to 2.03(1) A and the NPtN angles from 88.4(9) to 91.8(8)°. The ligands are almost planar and tilted towards the PtN4-plane by 82.1(8)–93.5(9)°.

Spectroscopic and structural study of the newly synthesized heteroligand complex of copper with creatinine and urea.

Abstract: Study of copper complex of creatinine and urea is very important in life science and medicine. In this paper, spectroscopic and structural study of a newly synthesized heteroligand complex of copper with creatinine and urea has been discussed. Structural studies have been carried out using DFT calculations and spectroscopic analyses were carried out by FT-IR, Raman, UV–vis absorption and fluorescence techniques. The copper complex of creatinine and the heteroligand complex were found to have much increased water solubility as compared to pure creatinine. The analysis of FT-IR and Raman spectra helps to understand the coordination properties of the two ligands and to determine the probable structure of the heteroligand complex. The LIBS spectra of the heteroligand complex reveal that the complex is free from other metal impurities. UV–visible absorption spectra and the fluorescence emission spectra of the aqueous solution of Cu–Crn–urea heteroligand complex at different solute concentrations have been analyzed and the complex is found to be rigid and stable in its monomeric form at very low concentrations.

A four-membered chelate complex of Cu(II) with creatinine

Abstract: The complex formation between Cu(II) and creatinine was studied by means of electronic, IR and EPR spectroscopy. The spectral data show the formation of a Cu(II) four-membered chelate with distorted rhombic structure.

Organometallic compounds containing a guanidinium group. Phenylmercury(II) derivatives of creatine and creatinine

Abstract: Phenylmercury(II) replaces a proton of creatine, H2NC+(NH2)NMeCH2C02-, in basic solution to form the zwitterionic complex PhHgNHC+(NH2)NMeCH2CO2-. Creatine and creatinine (C4H7N30) react with PhHg((OH)N03)I/2 in aqueous ethanol to form a 2:l complex [(PhHg)2(C4H6N30][N03] which exists in two crystalline forms. Creatinine forms a 1:l complex [PhHg(C4H7N30)][N03].1/2H20 at pH 1.4 on reaction with PhHg((OH)N03)l/2 in the presence of nitric acid. The 1:l and 2:l complexes may be interconverted. Creatinine hydronitrate, [H2NCNMeCH2CONH][NO3], and the PhHg(II) complexes of creatinine have similar infrared (including deuterated derivatives) and 1H NMR spectra, consistent with retention of the creatinine ring and presence of a guanidinium group in the complexes. An X-ray structural analysis of one crystalline form of the 2:l complex shows bonding of PhHg(II) groups to the exocyclic and ring nitrogens of creatinine to form the cation [PhHgNHCNMeCH2CONHgPh]+.