Helmut Sigel

Universität Hamburg

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Astrid Sigel

University of Basel

Antonı́n Holý

Czech Academy of Sciences, Institute of Organic Chemistry and Biochemistry

N. A. Corf�

University of Basel

Rolf Griesser

University of Basel

Virtudes Moreno

Universitat de Barcelona

Claudia A. Blindauer

University of Warwick

Nicolas A. Corfù

University of Basel

V. Rheinberger

Ivoclar Vivadent (Liechtenstein)

Bernd Knobloch

Technical University of Applied Sciences Würzburg-Schweinfurt

Bert P. Operschall

University of Basel

Cooperative Institutions

University of Basel

Institute of Inorganic Chemistry of the Slovak Academy of Sciences

Universitat de Barcelona

Czech Academy of Sciences, Institute of Organic Chemistry and Biochemistry

University of Zurich

Universidad de Granada

University of Konstanz

MSD (Mexico)

Walter de Gruyter (Germany)

Universidad de Zaragoza

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Stability and structure of binary and ternary metal ion complexes in aqueous solution of the quaternary 1-[2-(phosphonomethoxy)ethyl] derivative of 2,4-diaminopyrimidine (PMEDAPy−). Properties of an acyclic nucleotide analogue

Polyhedron (2003)

Alfonso Fernández‐Botello Antonı́n Holý Virtudes Moreno Helmut Sigel

Derivative (finance)

10.1016/s0277-5387(03)00093-7

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Citations (15)

Biogeochemical cycles of elements

Taylor & Francis eBooks (2005)

Astrid Sigel Helmut Sigel Roland K. O. Sigel

The Biogeochemical Cycles of Elements and the Evolution of Life. Biogeochemistry of Dihydrogen. Dioxygen over Geological Time. The Nitrogen Cycle: Its Biology. The Biological Cycle of Sulfur. Biological Cycling of Phosphorus. Iron, Phytoplankton Growth, and the Carbon Cycle, The Biogeochemistry and Fate of Mercury in the Environment. The Biogeochemistry of Cadmium. Biogeochemistry and Cycling of Lead

Biogeochemistry

Biogeochemical Cycle

Cycling

Mercury

Sulfur Cycle

Nitrogen Cycle

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Citations (25)

Stability of metal ion-thioether complexes

The Science of Nature (1975)

V. Rheinberger Helmut Sigel

Thioether

10.1007/bf00608706

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Citations (7)

Extent of intramolecular π stacks in aqueous solution in mixed-ligand copper(II) complexes formed by heteroaromatic amines and the anticancer and antivirally active 9-[2-(phosphonomethoxy)ethyl]guanine (PMEG). A comparison with related acyclic nucleotide analogues

Polyhedron (2015)

Claudia A. Blindauer Astrid Sigel Bert P. Operschall Rolf Griesser Antonı́n Holý

Phosphonate

Moiety

Nucleobase

10.1016/j.poly.2015.02.022

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Citations (6)

Facilitated Formation of High-Molecular-Weight Associates of Adenosine 5?-triphosphate (ATP)

The Science of Nature (1995)

Helmut Sigel Nicolas A. Corfù

Adenosine triphosphate

Adenosine diphosphate

10.1007/s001140050176

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Citations (0)

Metal Ions in Biological Systems. Vol. 1. Simple Complexes. 1974

Soil Science (1975)

Helmut Sigel

10.1097/00010694-197511000-00017

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Citations (2)

Metal ion-binding properties of (N3)-deprotonated uridine, thymidine, and related pyrimidine nucleosides in aqueous solution

Proceedings of the National Academy of Sciences (2005)

Bernd Knobloch Wolfgang Linert Helmut Sigel

The acidity constants for (N3)H of the uridine-type ligands (U) 5-fluorouridine, 5-chloro-2′-deoxyuridine, uridine, and thymidine (2′-deoxy-5-methyluridine) and the stability constants of the M(U–H) + complexes for M 2+ = Mg 2+ , Ca 2+ , Sr 2+ , Ba 2+ , Mn 2+ , Co 2+ , Ni 2+ , Cu 2+ , Zn 2+ , Cd 2+ , and Pb 2+ were measured (potentiometric pH titrations; aqueous solution; 25°C; I = 0.1 M, NaNO 3 ). Plots of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} \begin{equation*}{\mathrm{log}}K_{{\mathrm{M}}({\mathrm{U}}-{\mathrm{H}})}^{{\mathrm{M}}}\end{equation*}\end{document} vs. \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} \begin{equation*}{\mathrm{p}}K_{{\mathrm{U}}}^{{\mathrm{H}}}\end{equation*}\end{document} result in straight lines that are compared with previous plots for simple pyridine-type and o -amino(methyl)pyridine-type ligands as well as with the stabilities of the corresponding M(cytidine) 2+ complexes. The results indicate monodentate coordination to (N3) – in M(U–H) + for Co 2+ and Ni 2+ . For the M(U–H) + species of Cd 2+ , Zn 2+ , or Cu 2+ , increased stabilities imply that semichelates form, i.e., M 2+ is (N3) – -bound and coordinated water molecules form hydrogen bonds to (C2)O and (C4)O; these “double” semichelates are in equilibrium with “single” semichelates involving either (C2)O or (C4)O and possibly also with four-membered chelates for which M 2+ is innersphere-coordinated to (N3) – and a carbonyl oxygen. For the alkaline earth ions, semichelates dominate with the M 2+ outersphere bound to (N3) – and innersphere to one of the carbonyl oxygens. Mn(U–H) + is with its properties between those of Cd 2+ (which probably also hold for Pb 2+ ) and the alkaline earth ions. In nucleic acids, M 2+ –C(O) interactions are expected, if support is provided by other primary binding sites. (N3)H may possibly be acidified via carbonyl-coordinated M 2+ to become a proton donor in the physiological pH range, at which direct (N3) – binding of M 2+ also seems possible.

Cytidine

10.1073/pnas.0501446102

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Citations (60)

Facilitated formation of high-molecular-weight associates of adenosine 5?-triphosphate (ATP)

The Science of Nature (1995)

Helmut Sigel N. A. Corf�

Adenosine triphosphate

Adenosine diphosphate

10.1007/bf01133599

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Citations (5)