0000000000606188
AUTHOR
Alejandra Sornosa-ten
Effects of preorganization in the chelation of UO22+ by hydroxamate ligands: cyclic PIPO– vs linear NMA–
International audience; Many siderophores incorporate as bidentate chelating subunits linear and more seldomly cyclic hydroxamate groups. In this work, a comparative study of the uranyl binding properties in aqueous solution of two monohydroxamic acids, the prototypical linear N-methylacetohydroxamic acid (NMAH) and the cyclic analog 1-hydroxypiperidine-2-one (PIPOH), has been carried out. The complex [UO2(PIPO)(2)(H2O)] crystallized from slightly acidic water solutions (pH < 5), and its molecular structure was determined by X-ray diffraction. The uranyl speciation in the presence of both ligands has been thoroughly investigated in a 0.1 M KNO3 medium at 298.2 K by the combined use of four …
Acid–base properties of functionalised tripodal polyamines and their interaction with nucleotides and nucleic acids
Novel, highly positively charged tripodal polyamines with appended heterocyclic moieties revealed an intriguing panel of protonation species within the biologically relevant range. Studied compounds bind nucleotide monophosphates by mostly electrostatic interactions but only the imidazole analogue showed selectivity toward UMP in respect to other nucleotides. Strong binding of all the studied compounds to both ds-DNA and ds-RNA is to some extent selective toward the latter, showing rather rare RNA over DNA preference.
Conformational and structural studies of N-methylacetohydroxamic acid and of its mono- and bis-chelated uranium(VI) complexes
The thermodynamics and kinetics of the cis/trans isomerism of N-methylacetohydroxamic acid (NMAH) and its conjugated base (NMA(-)) have been reinvestigated in aqueous media by (1)H NMR spectroscopy. Hindered rotation around the central C-N bond due to electronic delocalization becomes slow enough on the NMR time scale to observe both rotamers in equilibrium in D2O at room temperature. By properly assigning the methyl group resonances, evidence for the prevalence of the E over the Z form is unambiguously provided [K300=[E]/[Z]=2.86(2) and 9.63(5) for NMAH and NMA(-), respectively], closing thereby a long-lasting dispute about the most stable conformer. To that end, calculations of the chemic…
Surface-Enhanced Raman Study of the Interactions between Tripodal Cationic Polyamines and Polynucleotides
Raman and surface-enhanced Raman spectra of new DNA/RNA-binding compounds consisting of three imidazole (Im) and three pyridine (Py) rings connected by tripodal polyaminomethylene linkages were obtained by the near-infrared excitation at 1064 nm. Study of interactions of Im and Py polyamines with single-stranded RNA polynucleotides (poly A, poly G, poly C, poly U), double-stranded DNA polynucleotides (poly dAdT-poly dAdT, poly dGdC-poly dGdC) and calf thymus DNA (ct-DNA) by surface-enhanced Raman spectroscopy (SERS) reveals unambiguous enhancement of the Raman scattering from the small molecules as well as appearance of new bands in spectra associated mainly with nucleobases. The SERS exper…
Kinetic study of the oxidation of [Fe(CN)6]4− by [Co(NH3)4pzCO2]2+ and S2O82- in the presence of the tripodal ligand Tren Aminopropil
Abstract Oxidations (electron transfers) of [Fe(CN)6]4− by [Co(NH3)4pzCO2]2+ and S 2 O 8 2 - have been studied in solutions containing the receptor N,N′,N″-(aminopropil)-tris (2-aminoetil) amina [Tren Aminopropil, TAL], which can incorporate [Fe(CN)6]4− and S 2 O 8 2 - but not the cobalt complex. The results can be explained using the Bronsted equation that allows to obtain the binding constant of the transition state, a parameter that the Pseudophase Model cannot provide.
Cu2+and AMP complexation of enlarged tripodal polyamines
The synthesis, characterization, Cu2+ coordination and interaction with AMP of three tripodal polyamines are reported. The polyamines are based on the structure of the tetraamine (tren) which has been enlarged with three propylamino functionalities (TAL), with a further anthrylmethyl fragment at one of its terminal primary nitrogens (ATAL) or with naphthylmethyl fragments at its three ends (N3TAL). The protonation constants of all three polyamines show that at pH 6, all six primary and secondary nitrogen atoms in the arms are protonated. The interaction with Cu2+ and AMP (adenosine-5′-monophosphate) has been studied by potentiometric, UV-Vis, ESI-MS spectroscopy and NMR techniques. pH-Metri…
CCDC 1042533: Experimental Crystal Structure Determination
Related Article: Stéphane Brandès, Alejandra Sornosa-Ten, Yoann Rousselin, Mickael Lagrelette, Christine Stern, Aurélien Moncomble, Jean-Paul Cornard, Michel Meyer|2015|J.Inorg.Biochem.|151|164|doi:10.1016/j.jinorgbio.2015.06.002
CCDC 1042608: Experimental Crystal Structure Determination
Related Article: Stéphane Brandès, Alejandra Sornosa-Ten, Yoann Rousselin, Mickael Lagrelette, Christine Stern, Aurélien Moncomble, Jean-Paul Cornard, Michel Meyer|2015|J.Inorg.Biochem.|151|164|doi:10.1016/j.jinorgbio.2015.06.002
CCDC 1579042: Experimental Crystal Structure Determination
Related Article: Alejandra Sornosa-Ten, Pawel Jewula, Tamas Fodor, Stéphane Brandès, Vladimir Sladkov, Yoann Rousselin, Christine Stern, Jean-Claude Chambron, Michel Meyer|2018|New J.Chem.|42|7765|doi:10.1039/C8NJ00166A
CCDC 1042532: Experimental Crystal Structure Determination
Related Article: Stéphane Brandès, Alejandra Sornosa-Ten, Yoann Rousselin, Mickael Lagrelette, Christine Stern, Aurélien Moncomble, Jean-Paul Cornard, Michel Meyer|2015|J.Inorg.Biochem.|151|164|doi:10.1016/j.jinorgbio.2015.06.002