Wiley InterScience Backfile Collection 1832-2000
Chemistry and Pharmacology
The interactions between diethyltin dichloride and 5′-CMP, 5′-dCMP, and 5′-UMP in aqueous solution were investigated by multinuclear 1D and 2D NMR techniques including 119Sn, 15N and 31P nuclei. These studies were combined with electrospray mass spectrometry, infrared spectroscopy, solid state 13C, 31P and 117Sn CP-MAS NMR, and elemental analysis. As demonstrated by 31P-1H HOESY spectroscopy, the diethyltin moiety interacts with the phosphate group of the pyrimidic mononucleotides in the pH range 0.5-3.5. Compound 8 (X = Cl), the solid isolated in this pH range from 5′-CMP, contains two tin atoms bridged by one oxygen and one chlorine atom, each tin atom being linked to the phosphate group of a nucleotide moiety. For 5′-UMP the solid isolated (12) has a dimeric structure with two different tin atoms; it can be formed by dimerization of compound 11 with the elimination of two water molecules. As demonstrated by 1H-119Sn HMQC correlation NMR data and the 2J(119Sn-O-117Sn) coupling constant of 156 Hz, the diethyltin moiety reacts with the O(2′) and O(3′) oxygen atoms of the nucleotides to form a dimeric diethyldioxastannolane at pH 〉 9.0. Between pH 5.0 and 9.0, no evidence for any interaction between the diethyltin moiety and the nucleotides was found.
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