Characterizing Emerging Canine H3 Influenza Viruses.

The continual emergence of novel influenza A strains from non-human hosts requires constant vigilance and the need for ongoing research to identify strains that may pose a human public health risk. Since 1999, canine H3 influenza A viruses (CIVs) have caused many thousands or millions of respiratory infections in dogs in the United States. While no human infections with CIVs have been reported to date, these viruses could pose a zoonotic risk. In these studies, the National Institutes of Allergy and Infectious Diseases (NIAID) Centers of Excellence for Influenza Research and Surveillance (CEIRS) network collaboratively demonstrated that CIVs replicated in some primary human cells and transmitted effectively in mammalian models. While people born after 1970 had little or no pre-existing humoral immunity against CIVs, the viruses were sensitive to existing antivirals and we identified a panel of H3 cross-reactive human monoclonal antibodies (hmAbs) that could have prophylactic and/or therapeutic value. Our data predict these CIVs posed a low risk to humans. Importantly, we showed that the CEIRS network could work together to provide basic research information important for characterizing emerging influenza viruses, although there were valuable lessons learned

Interacciones moleculares en quelatos metálicos de 2,6-piridina-dicarboxilato: estudio estructural

Tesis Univ. Granada. Departamento de Química Analítica. Leída el 9 de febrero de 200

Expected and unconventional Ag + binding modes in heteronuclear Pt,Ag coordination polymers derived from trans-[Pt(methylamine) 2(pyrazole) 2] 2+

Abstract The combination of AgNO3 and trans-[Pt(ma)2(Hpz)2]2+ (1; ma = methylamine; Hpz = neutral pyrazole) in water yields mixed Pt,Ag coordination polymers of different stoichiometries, depending on the ratio between Ag and Pt, as well as the pH. The products that were isolated and X-ray structurally characterized display both conventional (Ag+ coordination to pyrazole-N) and unconventional Ag+ binding modes (η1 and η2 binding to C atoms of the pyrazole/pyrazolate ligands; Pt → Ag dative bonds). Specifically, in trans-[Pt(ma)2(Hpz)2]Ag2(NO3)4 (2) and in trans-[Pt(ma)2(pz)2]2Ag3(NO3)3 (4), silver ions bind to C4 positions of Hpz (2) and pz– (4) ligands in η1 fashions, with Ag–C distances of 2.574(4) and 2.643(16) Å, respectively. In 4 there is additional cross-linking by a second Ag+ of N2 sites of adjacent pz– rings, further reinforced by weak dative bonds from Pt to Ag. Ag–N coordination to both a neutral Hpz and an anionic pz– ligand is observed in trans-[Pt(ma)2(pz)2]Ag2(Hpz)2(NO3)2 (5), with individual trinuclear PtAg2 entities associated through weak η2 contacts that involve the C3 and C4 positions of the neutral Hpz ligands. As in 4, intramolecular Pt–Ag distances of 3.1374(6) Å suggest weak dative bond interactions between Pt and Ag. The acidities of the two Hpz ligands in 1 are distinctly different (pKa values of 7.25 and 9.08 in H2O), thereby suggesting a stabilization of the monodeprotonated species trans-[Pt(ma)(Hpz)(pz)]+ (1c) in solution, probably through intermolecular hydrogen-bond formation between Hpz and pz– ligands.This work was supported by the Deutsche Forschungsgemeinschaft (DFG) and a postdoctoral fellowship from the Foundation Ramón Areces for P. B.-B. P. J. S. M. thanks the Spanish Ministry of Science and Innovation (MICINN) for funding through the “Ramón y Cajal” program.Peer Reviewe

Coordination of two different metal ions as reason for N-chirality in μ-amide complexes

The primary amine MeNH2, when bonded to PtII, is converted into a methylamide bridge upon coordination of a second, different metal ion (PdII), thereby making the N atom chiral. © 2011 The Royal Society of Chemistry.The authors acknowledge support from the Deutsche Forschungsgemeinschaft (DFG), the Ramón Areces Foundation (fellowship to PBB), and the “Ramón y Cajal” programme of the Spanish Ministry of Science and Innovation (PJSM).Peer Reviewe

A redetermination of (N9-adenine-[kappa]N)aqua[glycylglycinato(2-)-[kappa]3N,N',O]copper(II)

In the title complex, [Cu(C4H6N2O3)(C5H5N5)(H2O)], the CuII atom is five-coordinated in a square-pyramidal geometry by a tridentate glycylglycinate ligand (glygly), an N atom from an adenine ligand (Hade) and a water molecule in the apical position. The Hade coordination is reinforced by an intramolecular hydrogen-bonding interaction. A much lower precision structure has already been determined using intensities collected by the film method [Tomita, Izumo and Fujiwara (1973).Peer reviewe

cis-[N-(4-Chlorobenzyl)iminodiacetato-[kappa]3N,O,O']bis(1H-imidazole-[kappa]N3)copper(II)

In the title compound, [Cu(C11H10ClNO4)(C3H4N)2], the CuII atom is in a square-pyramidal coordination geometry, with the two imidazole ligands in cis positions and the N-(4-chlorobenzyl)iminodiacetate ligand occupying the apical and two cis-basal positions. In the crystal structure, molecules are linked into sheets by N-H...O hydrogen bonds.Peer reviewe

Interligand interactions involved in the molecular recognition between copper(II) complexes and adenine or related purines

16 pages, 17 figures, 2 Scheme.The available crystal structure information in the CSD database on ternary species prepared by the reaction of diverse copper(II) complexes (CuL) and purine, adenine and guanine or related purine derivatives is considered in order to deepen the intra-molecular interligand interactions affecting the molecular recognition patterns of the ‘metal complex + purine nucleobase’ and closely related systems. The degree of protonation and the possibilities of different tautomeric forms in the purine-like moieties are taken into account. The main conclusion is a general trend to form a Cusingle bondN(purine-like) coordination bond which can be reinforced by an intra-molecular interligand H-bonding interaction. Nsingle bondH(purines)cdots, three dots, centeredA (O or Cl acceptor) or Nsingle bondH(amino ligand L)cdots, three dots, centeredO6(oxo-purines) are commonly observed. In addition, selected examples revealed that the presence of a variety of non-coordinating groups in L or in the purine-like nucleobases can significantly influence the structurally observed molecular recognition pattern. Moreover, examples are known where binuclear cores of the types CuII2(μ2-N3,N9-adeninate)4(aqua)2 or CuI2(μ2-N3,N9-adeninate)2(aqua)2 recognise CuL chelates by means of the expectable pattern (Cusingle bondN7 coordination bond + N6single bondHcdots, three dots, centeredO(L) interaction).Financial support from ERDF-EC and MEC-Spain foundations (Project CTQ2006-15329-C02/BQU) is acknowledged. DChL thanks CSIC-EU for an I3P postdoctoral research contract and the support of the project “Factoría de Cristalización” CONSOLIDER INGENIO-2010. IGS thanks the University of Granada for her stay with Prof. Niclós-Gutiérrez's research group.Peer reviewe

Metal ion binding modes of hypoxanthine and xanthine versus the versatile behaviour of adenine

The metal coordination patterns of hypoxanthine, xanthine and related oxy-purines have been reviewed on the basis of the structural information available in the Cambridge Structural Database (CSD), including also the most recent reports founded in SciFinder. Attention is paid to the metal ion binding modes and interligand interactions in mixed-ligand metal complexes, as well as the possibilities of metal binding of the exocyclic-O atoms. The information in CSD is also reviewed for the complexes of adenine in cationic, neutral and anionic forms with every metal ion. In contrast to the scarce structural information about hypoxanthine and related complexes, large structural information is available for adenine complexes with a variety of metals that reveals some correlations between the crystal-chemical properties of metal ions. Three aspects are studied in deep: the coordination patterns, the interligand interactions influencing the molecular recognition in mixed-ligand metal complexes and the connectivity between metals for different adenine species, thus supporting its unique versatility as ligand. When possible, the overall behaviour showed by adenine metal complexes is discussed according to the HSAB Pearson criteria and the tautomeric behaviour observed for each protonated species of adenine. The differences between the roles of adenine and the referred oxypurines ligands are underlined

A Structural Study of the Iminodiacetate Moiety Conformation in N-(1-adamantyl)-iminodiacetate(2-) Copper(II) Complexes

9 pages, 11 figures, 1 table.N,N-bis(carboxymethyl)-1-adamantylamine acid (H2BCAA) or N-(1-adamantyl)-iminodiacetic acid forms zwitterions that are intra-stabilized by a bifurcated N+-H···O(carboxyl)2 interaction. In the crystal, both half-protonated carboxyl groups of H2BCAA± are involved in linear O-H···O inter-molecular bridges of 2.46Å. In the studied BCAA-CuII derivatives, the iminodiacetate-moiety of the BCAA chelating ligand exhibits a mer-NO2 conformation in [Cu(BCAA)(H2O)2] (1) and [Cu(BCAA)(Him)]2 (2), but a fac-O2+N(apical) conformation in [Cu(BCAA)(bpy)(H2O)]·3.5H2O (3) [Him = imidazole, bpy =2,2-bipyridine]. In clear contrast, dipyridylamine (dpya), as auxiliary ligand, seems to be unable to promote the fac-O2+N(apical) conformation in BCAA, as reveal the structures of two new salts with the trinuclear cation [(dpya)2Cu-2-Cu(BCAA)2-Cu(dpya)2]2+ and the anions [Cu(BCAA)2]2- (4) or NO3- (5), respectively.Financial support from ERDF-EC, MECSpain (Project CTQ2006-15329-C02/BQU) is acknowledged. ADM thanks for an initiation research grant of the University of Granada (Plan propio). DChL thanks CSIC-EU for an I3P postdoctoral research contract. The project “Factoría de Cristalización, CONSOLIDER INGENIO-2010” provided X-ray structural facilities for this work.Peer reviewe