Number of the records: 1

Extent of Intramolecular pi Stacks in Aqueous Solution in Mixed-Ligand Copper(II) Complexes Formed by Heteroaromatic Amines and 1-[2-(Phosphonomethoxy)ethyl]cytosine (PMEC), a Relative of Antivirally Active Acyclic Nucleotide Analogues (Part 72)

SYSNO ASEP	0424812
Document Type	J - Journal Article
R&D Document Type	Journal Article
Subsidiary J	Článek ve WOS
Title	Extent of Intramolecular pi Stacks in Aqueous Solution in Mixed-Ligand Copper(II) Complexes Formed by Heteroaromatic Amines and 1-[2-(Phosphonomethoxy)ethyl]cytosine (PMEC), a Relative of Antivirally Active Acyclic Nucleotide Analogues (Part 72)
Author(s)	Blindauer, C. A. (CH) Sigel, A. (CH) Operschall, B. P. (CH) Holý, Antonín (UOCHB-X) Sigel, H. (CH)
Number of authors	5
Source Title	Zeitschrift für anorganische und allgemeine Chemie. - : Wiley - ISSN 0044-2313 Roč. 639, 8-9 (2013), s. 1661-1673
Number of pages	13 s.
Language	eng - English
Country	DE - Germany
Keywords	nucleotide analogues ; antivirals ; complex stabilities ; isomers ; equilibria ; mixed ligand complexes
Subject RIV	CC - Organic Chemistry
Institutional support	UOCHB-X - RVO:61388963
UT WOS	000330180900048
EID SCOPUS	84880535321
DOI	10.1002/zaac.201300095
Annotation	Stability constants of the ternary Cu(Arm)(H;PMEC)(+) and Cu(Arm)(PMEC) complexes were measured by potentiometric pH titrations and compared with those of Cu(Arm)(H;PMEA)(+) and Cu(Arm)(PMEA) {PMEA(2-)} and related species. The basicity of the terminal phosphonate group is similar in PMEC2- and PMEA(2-). Stability-constant comparisons reveal, that in the monoprotonated ternary u(Arm)(H;PMEC)(+) complexes H+ is at the phosphonate group, that the ether oxygen atom of the -CH2-O-CH2-P(O)(2)(-) (OH) residue participates, next to the P(O)(2)(-)(OH) group, in Cu(Arm)(2+) coordination. The Cu(Arm)(PMEC) complexes are considerably more stable than the corresponding Cu(Arm)(R-PO3) species. The stability enhancements are mainly attributed to intramolecular stacks and to the formation of five-membered chelates involving the ether oxygen atom of the -CH2-O-CH2-P(O)(3)(2-) residue of PMEC2-. Analysis of the intramolecular equilibria reveals that ca. 10% of the isomeric ternary complexes exist with Cu(Arm)(2+) solely coordinated to the phosphonate group, ca. 25% as a five-membered chelate involving the ether oxygen, and ca. 65% with an intramolecular pi-pi stack between the pyrimidine moiety of PMEC2- and the rings of Bpy or Phen. It seems feasible that the reduced stacking intensity of PMEC2- and a different hydrogen bonding, leads to a different orientation of the cytosine (compared to adenine) in the active site of the nucleic acid polymerases, resulting in a reduced antiviral activity of PMEC compared to PMEA.
Workplace	Institute of Organic Chemistry and Biochemistry
Contact	asep@uochb.cas.cz ; Kateřina Šperková, Tel.: 232 002 584 ; Viktorie Chládková, Tel.: 232 002 434
Year of Publishing	2014

Number of the records: 1