Search Results - "Sigel, Helmut"

A Stability Concept for Metal Ion Coordination to Single-Stranded Nucleic Acids and Affinities of Individual Sites by Sigel, Roland K. O, Sigel, Helmut

“…The three-dimensional architecture and function of nucleic acids strongly depend on the presence of metal ions, among other factors. Given the negative charge…”
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Coordination Chemistry of Nucleotides and Antivirally Active Acyclic Nucleoside Phosphonates, including Mechanistic Considerations by Sigel, Astrid, Sigel, Helmut, Sigel, Roland K O

“…Considering that practically all reactions that involve nucleotides also involve metal ions, it is evident that the coordination chemistry of nucleotides and…”
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Nucleoside 5'-triphosphates: self-association, acid-base, and metal ion-binding properties in solution by Sigel, Helmut, Griesser, Rolf

“…Adenosine 5'-triphosphate (ATP(4-)) and related nucleoside 5'-triphosphates (NTP(4-)) serve as substrates in the form of metal ion complexes in enzymic…”
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Understanding the Acid-Base Properties of Adenosine: The Intrinsic Basicities of N1, N3 and N7 by Kapinos , Larisa E., Operschall, Bert P., Larsen, Erik, Sigel, Helmut

“…Adenosine (Ado) can accept three protons, at N1, N3, and N7, to give H3(Ado)3+, and thus has three macro acidity constants. Unfortunately, these constants do…”
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(N7)-Platination and its effect on (N1)H-acidification in nucleoside phosphate derivatives by Sigel, Astrid, Operschall, Bert P., Griesser, Rolf, Song, Bin, Okruszek, Andrzej, Odani, Akira, Katsuta, Tsuguno, Lippert, Bernhard, Sigel, Helmut

“…A systematic study of the acidification of two adjacent guanine nucleobases in di- and short oligonucleotides by (am/mine)2Pt(II) entities coordinated via N7…”
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Xanthosine 5'-monophosphate (XMP). Acid-base and metal ion-binding properties of a chameleon-like nucleotide by Sigel, Helmut, Operschall, Bert P, Griesser, Rolf

“…The four acidity constants of threefold protonated xanthosine 5'-monophosphate, H(3)(XMP)(+), reveal that in the physiological pH range around 7.5 (X - H x…”
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Metal Ion-Binding Properties of (N3)-Deprotonated Uridine, Thymidine, and Related Pyrimidine Nucleosides in Aqueous Solution by Knobloch, Bernd, Linert, Wolfgang, Sigel, Helmut, Gray, Harry B.

“…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)…”
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Intrinsic Acid-Base Properties of a Hexa-2′-deoxynucleoside Pentaphosphate, d(ApGpGpCpCpT): Neighboring Effects and Isomeric Equilibria by Domínguez-Martín, Alicia, Johannsen, Silke, Sigel, Astrid, Operschall, Bert P., Song, Bin, Sigel, Helmut, Okruszek, Andrzej, González-Pérez, Josefa María, Niclós-Gutiérrez, Juan, Sigel, Roland K. O.

“…The intrinsic acid‐base properties of the hexa‐2′‐deoxynucleoside pentaphosphate, d(ApGpGpCpCpT) [=(A1⋅G2⋅G3⋅C4⋅C5⋅T6)=(HNPP)5−] have been determined by 1H NMR…”
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Inosylyl(3′→5′)inosine (IpI–). Acid–Base and Metal Ion-Binding Properties of a Dinucleoside Monophosphate in Aqueous Solution by Knobloch, Bernd, Okruszek, Andrzej, Sigel, Helmut

“…The acidity constants of the (N7)H+ sites of inosylyl(3′→5′)inosine (IpI−) were estimated and those of its (N1)H sites were measured by potentiometric pH…”
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Effects of (N7)-Coordinated Nickel(II), Copper(II), or Platinum(II) on the Acid-Base Properties of Guanine Derivatives and Other Related Purines[≠] by Song, Bin, Zhao, Jing, Griesser, Rolf, Meiser, Cordula, Sigel, Helmut, Lippert, Bernhard

“…Guanine is an important nucleobase residue in nucleic acids; for example, the anticancer drug cisplatin, cis‐[(NH3)2PtCl2], preferably binds to N7 of this…”
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Two Metal Ions Coordinated to a Purine Residue Tolerate Each Other Well by Knobloch, Bernd, Sigel, Roland K. O., Lippert, Bernhard, Sigel, Helmut

“…The catalytic sites of ribozymes generally contain two or more metal ions. Guanine is the nucleobase most often involved in binding to metal ions. The…”
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Acid−Base and Metal Ion Binding Properties of Guanylyl(3‘→5‘)guanosine (GpG-) and 2‘-Deoxyguanylyl(3‘→5‘)-2‘-deoxyguanosine [d(GpG)-] in Aqueous Solution by Da Costa, Carla P, Sigel, Helmut

“…The acidity constants of guanylyl(3‘→5‘)guanosine (GpG-) and 2‘-deoxyguanylyl(3‘→5‘)-2‘-deoxyguanosine [d(GpG)-] for the deprotonation of their (N1)H sites…”
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Extent of metal ion–sulfur binding in complexes of thiouracil nucleosides and nucleotides in aqueous solution by Odani, Akira, Kozlowski, Henryk, Swiatek-Kozlowska, Jolanta, Brasuń, Justyna, Operschall, Bert P., Sigel, Helmut

“…Previously published stability constants of several metal ion (M 2+) complexes formed with thiouridines and their 5′-monophosphates, together with recently…”
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Intrinsic Acid−Base Properties of Purine Derivatives in Aqueous Solution and Comparison of the Acidifying Effects of Platinum(II) Coordinated to N1 or N7:  Acidifying Effects Are Reciprocal and the Proton “Outruns” Divalent Metal Ions by Griesser, Rolf, Kampf, Gunnar, Kapinos, Larisa E, Komeda, Seiji, Lippert, Bernhard, Reedijk, Jan, Sigel, Helmut

“…The effect of Pt2+ coordination, in particular of (dien)Pt2+ or cis-(NH3)2Pt2+, on the acid−base properties of the purine ligands 9-ethylguanine (9EtG),…”
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The bio-relevant metals of the periodic table of the elements by Sigel, Helmut, Sigel, Astrid

“…The bio-relevant metals (and derived compounds) of the ( ) are in the focus. The bulk elements sodium (Na), potassium (K), magnesium (Mg), and calcium (Ca)…”
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Comparison of the Surprising Metal-Ion-Binding Properties of 5- and 6-Uracilmethylphosphonate (5Umpa2− and 6Umpa2−) in Aqueous Solution and Crystal Structures of the Dimethyl and Di(isopropyl) Esters of H2(6Umpa) by Freisinger, Eva, Griesser, Rolf, Lippert, Bernhard, Moreno-Luque, Cristóbal F., Niclós-Gutiérrez, Juan, Ochocki, Justyn, Operschall, Bert P., Sigel, Helmut

“…5‐ and 6‐Uracilmethylphosphonate (5Umpa2− and 6Umpa2−) as acyclic nucleotide analogues are in the focus of anticancer and antiviral research. Connected…”
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Acid–base and metal ion binding properties of 2-thiocytidine in aqueous solution by Brasuń, Justyna, Matera, Agnieszka, Sochacka, Elżbieta, Swiatek-Kozlowska, Jolanta, Kozlowski, Henryk, Operschall, Bert P., Sigel, Helmut

“…The thionucleoside 2-thiocytidine (C2S) occurs in nature in transfer RNAs; it receives attention in diverse fields like drug research and nanotechnology. By…”
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Acid-Base and Metal-Ion-Coordinating Properties of Benzimidazole and Derivatives (= 1,3-Dideazapurines) in Aqueous Solution: Interrelation between Complex Stability and Ligand Basicity by Kapinos, Larisa E., Song, Bin, Sigel, Helmut

“…The 1,3‐dideazapurine (benzimidazole) residue occurs in a wide range of biologically active compounds, many of which are also metal‐ion dependent in their…”
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Metal ion-coordinating properties of imidazole and derivatives in aqueous solution: interrelation between complex stability and ligand basicity by Kapinos, Larisa E., Song, Bin, Sigel, Helmut

“…The stability constants of the 1:1 complexes formed between Mg 2+, Ca 2+, Sr 2+, Ba 2+, Mn 2+, Co 2+, Ni 2+, Cu 2+, Zn 2+ or Cd 2+ (M 2+) and the simple,…”
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Acid-base properties of the nucleic-acid model 2'-deoxyguanylyl(5'-->3')-2'-deoxy-5'-guanylate, d(pGpG)3-, and of related guanine derivatives by Knobloch, Bernd, Sigel, Helmut, Okruszek, Andrzej, Sigel, Roland K O

“…The dinucleotide d(pGpG) is an often employed DNA model to study various kinds of interactions between DNA and metal ions, but its acid-base properties were…”
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