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Gustavo Echeverría,1,2 Armando Reyna-Bello,3 Elizabeth Minda-Aluisa,1 Maritza Celi-Erazo,1 Lisbeth Olmedo,1 Herakles A García,4 Miguel Angel Garcia-Bereguiain,5–7 Jacobus H de Waard,5,8 On behalf of the UNU/BIOLAC network for infectious cattle diseases1Instituto de Investigación en Salud Publica y Zoonosis (CIZ), Universidad Central del Ecuador, Quito, Ecuador; 2Facultad de Ciencias Veterinarias, Programa de Doctorado, Universidad de Buenos Aires, Buenos Aires, Argentina; 3Departamento de Ciencias de la Vida y la Agricultura, Carrera de Ingeniería en Biotecnología, Universidad de las Fuerzas Armadas ESPE, Santo Domingo, Ecuador; 4Departamento de Parasitologia, Instituto de Ciências Biomédicas, University of São Paulo, São Paulo, Brazil; 5One Health Research Group. Facultad de Ciencias de la Salud, Universidad de Las Américas (UDLA), Quito, Ecuador; 6School of Biological Sciences and Engineering, Yachay Tech, Urcuquí, Ecuador; 7Laboratorio para Investigaciones Biomedicas. Facultad de Ciencias de la Vida, Escuela Superior Politécnica del Litoral, Guayaquil, Ecuador; 8Instituto de Biomedicina Dr. Jacinto Convit, Universidad Central de Venezuela, Caracas, VenezuelaBackground: Q fever is an underreported zoonotic disease of cattle and men in most countries of the world. Very little information about the prevalence of Coxiella burnetii infection in animals and humans comes from South and Central America and systematic studies are lacking. Methods: A seroprevalence survey for Q fever amongst cattle, farm workers and students was conducted in Ecuador using a commercial ELISA kit.Results: Survey results showed an unexpectedly high prevalence of Coxiella burnetii antibodies in dairy cattle (43%) and in farm workers (34%). In addition, a clinical case in a human of acute Q fever in the convalescent stage was detected. Conclusion: We conclude that the disease is endemic in Ecuador but is overlooked by medical and laboratory personnel. Q fever should be considered a public health issue in Ecuador and further research into the clinical relevance of this infection is recommended.Keywords: Q fever, Coxiella burnetii, Ecuador, phase I antibodies, phase II antibodies

Two new 1,3-dicarbonyl compounds bearing an o-hydroxyphenyl moiety (for short, I and II) were synthesized and subjected to structural, experimental and theoretical studies. Vibrational spectroscopy (IR and Raman) and X-ray diffraction were used for solid phase studies, while NMR and electron spectroscopy allowed analysis in solution. The crystal structures of I and II, determined by X-ray diffraction methods, are closely related to each other (rms deviation of homologous atoms from their best fit is 0.147 Å). The observed planarity of β-hydroxyphenylcarbonyl enols fragment in the compounds is enforced by both extended π-bonding and intramolecular OH⋯O bonds. Molecules in I are arranged in the lattice as center-symmetric dimers held by relatively weak intermolecular OH⋯O bonds. Hirshfeld surface (HS) analysis, atoms in molecules (QTAIM), and natural bonding orbitals (NBO) approaches were employed to study theoretically selected dimers constructed from X-ray data. The results were combined with experimental ones to obtain deep insight into the strength and type of intermolecular interactions. A chalcogen bond interaction was detected in I. Although the O⋯O interaction is unusual, it participates in the attractive forces that stabilize the crystal lattice. The title compounds are present in the solid state only as the keto–enol tautomer, while in solution the diketo tautomer is also detected at concentrations of 5%. In vitro studies showed that I have better antimicrobial properties than II, mainly against the S. aureus strain. [ABSTRACT FROM AUTHOR]

The solid-state molecular structures of N-(butylcarbamothioyl)-4-methoxybenzamide (I) and N-(butylcarbamoyl)-4-methoxybenzamide (II) were used as examples for structural analyses of carbonylthioureides and carbonylureides. Both compounds crystallize in the monoclinic P21/c space group and form nearly identical hydrogen-bonded dimeric aggregates. A thorough examination of intermolecular interactions using X-ray diffraction data, Hirshfeld surface analysis, molecular electrostatic potential maps, NBO and QTAIM approaches, and spectroscopic techniques reveals that the larger size of the sulfur atom has a significant impact on the strength and nature of the interactions within the crystal lattice. Furthermore, the isosteric exchange was evaluated by testing the activity of both compounds as antibiofilm and anti-quorum sensing agents. [ABSTRACT FROM AUTHOR]

During the synthesis of the Schiff base 2-methoxy-6-{[(tiophen-2-methyl)imino]methyl}phenol (o-HVATPNH2), a co-product was isolated and characterized. The crystal structure of this molecule, 4,10-dimethoxy-13-(thiophen-2-ylmethyl)-6,12-dihydro-6,12-epiminodibenzo[b,f][1,5]dioxocane, namely (o-VA)2TPNH2 for short, was determined by X-ray diffraction methods. The chiral compound crystallizes as a racemate in the triclinic space group P1¯ with 2 molecules per unit cell. The (o-VA)2 molecular fragment in (o-VA)2TPNH2 shows a non-crystallographic two-fold axis that enables the two molecular stereogenic centers to have the same chirality. The formation reaction mechanism for (o-VA)2TPNH2 is proposed and the structural properties of the Schiff base o-HVATPNH2 were revised. Evidence of the presence of the zwitterionic form of a Schiff base in the solid state was found. [ABSTRACT FROM AUTHOR]

Two new thiourea (1) and urea (2) derivatives, substituted with 2-trifluoromethyl-4H-chromen-3-yl moieties at defined positions, were obtained by convenient synthetic methodologies. The pure compounds were studied in solid state by vibrational spectroscopy (FT-IR and Raman) and in solution by NMR and UV-Vis spectroscopy. The crystal structure of the urea derivative (compound 2) was also determined by X-ray diffraction. The crystal packing is governed by N-H···O intramolecular interactions of moderate strength in a self-assembled dimer of the terminal amide fragment (C(=O)-NH2). Hirshfeld surface and 2D-fingerprint plots were also performed to characterise the role in the packing stabilisation of all contacts, including weak C-H···F hydrogen bonds and π-π stacking interactions. For both compounds, the tentative assignment of vibrational and electronic spectra was assisted by theoretical calculations. Besides, to evaluate the influence on the pharmacokinetic and pharmacodynamic properties of molecules with -CF3 groups, the anti-microbial activity of the title compounds was tested against the standard strains of various Gram-positive and Gram-negative organisms with noteworthy antimicrobial effect over Staphylococcus aureus, Klebsiella pneumoniae and Salmonella typhi. [ABSTRACT FROM AUTHOR]

We show here that the phenomenon of spontaneous resolution of enantiomers occurs during the crystallization of the sodium and rubidium double salts of the transition metal complex tris(oxalato)ferrate(III), namely sodium pentarubidium bis[tris(oxalato)ferrate(III)], NaRb5[Fe(C2O4)3]2. One enantiomer of the salt crystallizes in the cubic space group P4332 with Z = 4 and a Flack absolute structure parameter x = -0.01 (1) and its chiral counterpart in the space group P4132 with x = -0.00 (1). All metal ions are at crystallographic special positions: the iron(III) ion is on a threefold axis, coordinated by three oxalate dianions in a propeller-like conformation. One of the two independent rubidium ions is on a twofold axis in an eightfold coordination with neighbouring oxalate oxygen atoms, and the other one on a threefold axis in a sixfold RbO6 coordination. The sodium ion is at a site of D3 point group symmetry in a trigonal-antiprismatic NaO6 coordination. [ABSTRACT FROM AUTHOR]

We show here that the phenomenon of spontaneous resolution of enantiomers occurs during the crystallization of the sodium and rubidium double salts of the transition metal complex tris(oxalato)ferrate(III), namely sodium pentarubidium bis[tris(oxalato)ferrate(III)], NaRb5[Fe(C2O4)3]2. One enantiomer of the salt crystallizes in the cubic space group P4332 with Z = 4 and a Flack absolute structure parameter x = -0.01 (1) and its chiral counterpart in the space group P4132 with x = -0.00 (1). All metal ions are at crystallographic special positions: the iron(III) ion is on a threefold axis, coordinated by three oxalate dianions in a propeller-like conformation. One of the two independent rubidium ions is on a twofold axis in an eightfold coordination with neighbouring oxalate oxygen atoms, and the other one on a threefold axis in a sixfold RbO6 coordination. The sodium ion is at a site of D3 point group symmetry in a trigonal-antiprismatic NaO6 coordination. [ABSTRACT FROM AUTHOR]

A detailed structural and spectroscopic study of a new thiourea derivative 1-butyl-3-(1-naphthoyl)thiourea (1) is presented with the assistance of theoretical calculations. The X-ray diffraction structure analysis reveals a planar carbonylthiourea group, favoured by intra-molecular NH···O bond. The compound is arranged in the lattice as NH···O and NH···S bonded polymeric ribbons, that extend along the crystalb-axis. Molecular pairs involving N–H···S hydrogen bonds are a dominant contribution to packing stabilisation coming from coulombic component. Hirshfeld surfaces and two-dimensional-fingerprint plots show different intermolecular contacts and its relative contributions to total surface in each compound. The AIM approach shows the nature and strength of the strong and weak intramolecular interactions and the solvent effect, while NBO analysis reveals that the sulphur atom is responsible for the higher hyperconjugative stabilising energy. [ABSTRACT FROM PUBLISHER]