Metal Ion-Binding Properties of (1H-Benzimidazol-2-yl-methyl)phosphonate (Bimp2-) in Aqueous Solution.⊥Isomeric Equilibria, Extent of Chelation, and a New Quantification Method for the Chelate Effect

2004 ◽  
Vol 43 (4) ◽  
pp. 1311-1322 ◽  
Author(s):  
María José Sánchez-Moreno ◽  
Alfonso Fernández-Botello ◽  
Raquel B. Gómez-Coca ◽  
Rolf Griesser ◽  
Justyn Ochocki ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Metal Ion ◽  
Ion Binding ◽  
Metal Ion Binding ◽  
Binding Properties ◽  
Quantification Method ◽  
Chelate Effect ◽  
Isomeric Equilibria

Metal Ion-Binding Properties of the Nucleotide Analogue 1-[2-(Phosphonomethoxy)ethyl]cytosine (PMEC) in Aqueous Solution

1999 ◽  
Vol 64 (4) ◽  
pp. 613-632 ◽  
Author(s):  
Claudia A. Blindauer ◽  
Antonín Holý ◽  
Helmut Sigel
Keyword(s):  
Aqueous Solution ◽  
Metal Ions ◽  
Metal Ion ◽  
Ion Binding ◽  
Metal Ion Binding ◽  
Binding Properties ◽  
Nucleotide Analogue ◽  
Ether Oxygen ◽  
The Stability ◽  
Isomeric Equilibria

The acidity constants of the twofold protonated nucleotide analogue 1-[2-(phosphonomethoxy)ethyl]cytosine, H2(PMEC)±, as well as the stability constants of the M(H;PMEC)+ and M(PMEC) complexes with the metal ions M2+ = Mg2+, Ca2+, Sr2+, Ba2+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, and Cd2+ have been determined by potentiometric pH titrations in aqueous solution at I = 0.1 M (NaNO3) and 25 °C. Comparison with previous results for the nucleobase-free compound (phosphonomethoxy)ethane, PME, and the parent nucleotides cytidine 5'-monophosphate (CMP2-) and 2'-deoxycytidine 5'-monophosphate (dCMP2-) shows that the metal ion-binding properties of PMEC2- resemble closely those of PME2-: This means, the primary binding site is the phosphonate group and with all of the metal ions studied, 5-membered chelates involving the ether oxygen of the -CH2-O-CH2-PO32- chain are formed. The position of the isomeric equilibria between these chelates and the "open" complexes, -PO32-/M2+ is calculated; the degree of formation of the chelates is identical within the error limits for the M(PME) and M(PMEC) systems. Hence, like in M(CMP) and M(dCMP) no interaction occurs with the cytosine residue in the M(PMEC) complexes. However, the monoprotonated M(H;PMEC)+ as well as the M(H;CMP)+ and M(dCMP)+ species carry the metal ion predominantly at the nucleobase, while the proton is at the phosph(on)ate group. The coordinating properties of PMEC2- and CMP2- or dCMP2- differ thus only with respect to the possible formation of the 5-membered chelates involving the ether oxygen in M(PMEC) species, a possibility which does not exist in the complexes of the parent nucleotides. Possible reasons why PMEC is devoid of a significant antiviral activity are shortly discussed.

Ambivalent metal ion binding properties of cytidine in aqueous solution

1992 ◽  
Vol 31 (26) ◽  
pp. 5588-5596 ◽  
Author(s):  
Yoshiaki Kinjo ◽  
Liangnian Ji ◽  
Nicolas A. Corfu ◽  
Helmut Sigel
Keyword(s):  
Aqueous Solution ◽  
Metal Ion ◽  
Ion Binding ◽  
Metal Ion Binding ◽  
Binding Properties

Metal Ion-Binding Properties in Aqueous Solution of the Nucleoside Analogue, 5,6-Dichloro-1-(β-ᴅ-ribofuranosyl)benzimidazole (DRB)

1998 ◽  
Vol 53 (8) ◽  
pp. 903-908 ◽  
Author(s):  
Larisa E. Kapinos ◽  
Bin Song ◽  
Helmut Sigel
Keyword(s):  
Aqueous Solution ◽  
Metal Ion ◽  
Ion Binding ◽  
Acidity Constant ◽  
Metal Ion Binding ◽  
Binding Properties ◽  
Straight Line ◽  
Data Points ◽  
The Stability ◽  
Straight Lines

Abstract The stability constants of the 1:1 complexes formed between Mg2+, Ca2+, Sr2+, Ba2+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+ or Cd2+ (= M2+) and 5,6-dichloro-l-(β-ᴅ-ribofuranosyl)benzim idazole (DRB) were determined by potentiom etric pH titrations in aqueous solution (25 °C; I = 0.5м, NaNO3). The acidity constant of H(DRB)+, the proton being at N3, was measured by the same method and the result was confirmed via spectrophotometry. Based on previously established [L. E. Kapinos, B. Song, H. Sigel, Inorg. Chim . Acta 280, in press (1998)] logммʟ versus Kʜʜʟ straight-line plots for complexes of imidazole-type ligands it is shown for the Mn(DRB)2+ and Zn (DRB)2+ complexes, as examples, that the benzene ring of the benzim idazole residue exerts a steric inhibition for metal ion binding at N3; i.e., the data points for the M(DRB)2+ complexes fall clearly below the straight lines defined by the imidazole- type ligands.

scholarly journals Acid–base and metal ion binding properties of 2-thiocytidine in aqueous solution

2008 ◽  
Vol 13 (5) ◽  
pp. 663-674 ◽  
Author(s):  
Justyna Brasuń ◽  
Agnieszka Matera ◽  
Elżbieta Sochacka ◽  
Jolanta Swiatek-Kozlowska ◽  
Henryk Kozlowski ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Metal Ion ◽  
Ion Binding ◽  
Metal Ion Binding ◽  
Acid Base ◽  
Binding Properties
Sign in / Sign up

Export Citation Format

Share Document