Multi-drug-resistant bacteria (MDR) are the cause of different infections and diseases that have affected humanity for a long time, and have been an emerging global health problem that has led to increased morbidity and mortality. The growing emergence of MDR bacteria has underlined the need for development and discovery of new antibacterial compounds. In this context, a series of new paeonol 1,2,3-triazole and ether derivatives were synthesized using copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction and nucleophilic substitution. Paeonol has been a natural product widely studied due to its many biological activities, as well as its derivatives. Three ether derivatives (two unpublished) and ten triazole derivatives (six unpublished) of paeonol were obtained, which were determined by nuclear magnetic resonance (NMR), Fourier transform infrared spectrometry (FTIR), Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS) and six of them by X-rays, which is the first study of this type presented for these compounds. All the synthesized compounds were evaluated as antibacterial agents against Staphylococcus aureus and Escherichia coli, obtaining a minimum inhibitory concentration (MIC) above 100 µg mL-1. The results showed that CuAAC and nucleophilic substitution were very useful to obtain new paeonol triazole and ether derivatives and the products were obtained in yields from 21.3 to 98.5%. The advantages of these reactions (high yield in most compounds, reaction time, low impurities) show that using the method to produce new derivatives is advisable thus assisting in the discovery of new potential bioactive compounds.

Abstract Infections are frequent complications of kidney transplants. We aimed at determining the frequency and type of infections that occur in renal transplant recipients during the early (0-1 month), intermediate (1-6 months) and late (6-12 months) post-transplant period and analyzing the risk factors for infection. To this aim, we conducted a retrospective cohort study on 1-year post-transplant follow-up in two third-level university hospitals in Cordoba city. All consecutive recipients of renal transplants performed between 2009 and 2015 were included, except those with multiple solid organ transplantation and pediatric patients. We included 375 recipients, of which 235 (62.7%) had at least one episode of infection during follow-up. There were 504 episodes of infection, of which 131 (26%) occurred in the early, 272 (53.9%) in the intermediate, and 101 (20.1%) in the late post-transplant period. The most frequent infections in all periods were caused by bacteria (mainly urinary tract infections), and the most frequent viral infection was caused by Cytomegalovirus (mainly in the second and third period). In the multivariate analysis, infection risk factors were: age > 60 years (adjusted odds ratio [aOR] = 1.92; 95% CI = 1.05-3.49), organ transplantation from deceased donor (aOR = 8.19; 95% CI = 2.32-28.9), use of pigtail catheter for urinary tract drainage (aOR = 4.06; 95% CI = 1.27-12.9), and number of days in hospital after transplant (aOR = 1.05; 95% CI = 1.01-1.11). In conclusion, infections in renal transplant recipients represent a very frequent health problem in our hospitals. Understanding the local epidemiology of infection and the potential risk factors for infection acquires utmost importance.

Resumen Las infecciones son complicaciones frecuentes de los trasplantes renales. Los objetivos del estudio fueron determinar la frecuencia y el tipo de infecciones que ocurren en el período post-trasplante temprano (0-1 mes), intermedio (1-6 meses) y tardío (6-12 meses) en nuestro medio y analizar los factores de riesgo de infección. Se realizó un estudio de cohorte retrospectivo que incluyó todos los pacientes con trasplantes renales realizados entre 2009 y 2015 en dos hospitales universitarios de tercer nivel de la ciudad de Córdoba, excluidos los receptores de trasplante simultáneo de múltiples órganos sólidos y los menores de 18 años. Fueron incluidos 375 pacientes, de los cuales 235 (62.7%) tuvieron al menos un episodio de infección. Hubo 504 episodios de infección: 131 (26%) ocurrieron en el período temprano, 272 (53.9%) en el intermedio y 101 (20.1%) en el tardío. La mayoría de las infecciones fueron de origen bacteriano (principalmente del tracto urinario). La mayoría de las infecciones virales ocurrieron en el segundo y el tercer período y Citomegalovirus fue el responsable más frecuente. En el análisis multivariado, los factores de riesgo de infección post-transplante renal fueron: edad > 60 años (odds ratio ajustado [aOR] 1.92; IC95% 1.05-3.49), donante cadavérico (aOR 8.19; IC95% 2.32-28.9), uso de catéter pigtail (aOR 4.06; IC95% 1.27-12.9) y número de días internado postrasplante (aOR 1.05; IC95% 1.01-1.11). En conclusión, confirmamos que las infecciones en pacientes con trasplante renal son muy frecuentes en nuestro medio, por lo cual es importante conocer la epidemiología local y los factores de riesgo.

The preparation, characterization, theoretical calculations and biological application of four RuII complexes with 2-picolinate (pic), 2,2’-bipyridine (bipy) and P-P as ligands [P-P = 1,1-bis(diphenylphosphino)methane (dppm-1), 1,2-bis(diphenylphosphino)ethane (dppe-2), 1,3-bis(diphenylphosphino)propane (dppp-3) or 1,1’-bis(diphenylphosphino)ferrocene (dppf-4)], is here presented. The complexes 1-4, with general formula [Ru(pic)(P-P)(bipy)]PF6, were characterized by elemental analysis and by infrared (IR), UV-Vis, nuclear magnetic resonance (NMR 1H and 13P{1H}) spectroscopies, cyclic voltammetry and X-ray crystallography technique. Additionally, preliminary in vitro tests against human breast (MDA-MB-231) and murine ascitic sarcoma 180 (S180) tumor cell lines were carried out, and compared with cisplatin, a reference drug. The drug concentration at which 50% of the cells are viable relative to the control (IC50) values found for complexes 1, 2, 3 and 4 against MDA-MB-231 tumor cells were around 14.6, 7.6, 3.3 and 0.4 µM, respectively, while against S180 tumor cells these complexes showed IC50 values of 71.9, 31.3, 11.2 and 3.5 µM, respectively. Therefore, the complexes were more active against MDA-MB-231 than S180.

A thiourea derivative, N-[(phenylcarbonyl)carbamothioyl]benzamide, was synthesized and characterized by elemental analysis, thermal analysis, spectroscopic methods (Fourier transform infrared (FTIR), UV-Vis, Raman, matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF), tandem mass spectrometry (MS/MS) and nuclear magnetic resonance (NMR)) and quantum-chemical calculations. The synthetic route was simple and efficient, conducted just by one-step and no purification step was needed. The compound crystallizes in a non-centrosymmetric orthorhombic crystal system with a P21 21 21 space group, with a= 5.06220(10) Å, b= 11.8623(3) Å, c= 21.9682(8) Å. The molecular conformation of the solid is stabilized by the N-H···O intramolecular hydrogen bond, which was present in the X-ray structure and was also found in the optimized geometry. The theoretical analysis showed that this strong interaction remains even when molecules are solvated, i.e., the rotation barrier and the hydrogen bond strength are greater than the solvent stabilization energy. In addition to this hydrogen bond effect, the relative position of phenyl groups has a certain influence on the chemical behavior of this thiourea and probably for other phenylthioureas.

Dois novos complexos zwitteriônicos de oxorrênio(V), [ReOCl2(Hdhp)(PPh3)] (1) e [ReOBr2(Hdhp)(PPh3)] (2) (H2dhp = 2,3-dihidroxipiridina), foram sintetizados e caracterizados por espectroscopia de absorção no infravermelho, ressonância magnética nuclear de ¹H e 31P, análise elementar e determinação da estrutura cristalina e molecular por difração de raios X em monocristais. Os complexos apresentam geometria de coordenação octaédrica bastante distorcida, com os dois ligantes haletos arranjados em posições cis equatoriais, o ligante trifenilfosfina em posição trans a um dos haletos e o ligante Hdhp- coordenado de forma bidentada através de seus átomos de oxigênio, sendo um em posição trans ao ligante oxo e o outro em posição trans com relação ao outro haleto. Este ligante tem seu átomo de nitrogênio protonado. Os compostos 1 e 2 apresentam empacotamento cristalino bastante diferente, influenciado em ambos os casos por ligações de hidrogênio intermoleculares dos tipos N-H<FONT FACE=Symbol>...</FONT>X (X = Cl, Br) e N-H...O.

Two novel zwitterionic oxorhenium(V) complexes, [ReOCl2(Hdhp)(PPh3)] (1) and [ReOBr2(Hdhp)(PPh3)] (2) (H2dhp = 2,3-dihydroxypyridine), were synthesized and characterized by infrared spectroscopy, ¹H and 31P nuclear magnetic resonance, elemental analysis and crystal and molecular structure determination by X-ray diffraction on single crystals. Both complexes show distorted octahedral coordination geometry, with the halide ligands arranged in equatorial cis positions, the triphenylphosphine ligand in a trans position to one of the halides and the Hdhp- ligand coordinated in a bidentate form through its oxygen atoms, one in trans position to the oxo-ligand and the other in trans position to the second halide. The nitrogen atom of this ligand is protonated. Compounds 1 and 2 show quite different crystal packing, both influenced by hydrogen bonds of the types N-H...X (X = Cl, Br) and N-H<FONT FACE=Symbol>...</FONT>O.

A 2-hidroxi-4,6-dimetoxiacetofenona foi isolada de folhas de Peperomia glabella (família Piperaceae). A substância cristaliza no grupo espacial P1 com duas moléculas na unidade assimétrica. A análise estrutural revela uma rede bidimensional infinita no plano (011), estabilizada por ligações de hidrogênio inter-moleculares ao longo da direção [100] e interações de van der Waals ao longo da direção [011]. As moléculas apresentam fortes ligações de hidrogênio intra-moleculares [O1-HO1...O4 = 1,53(2) Å e O5-HO5...O8 = 1,38(2) Å]. A conformação molecular foi analisada usando o MOGUL, uma base de dados de geometria molecular derivada do CSD (Cambridge Structural Database).

The 2-hydroxy-4,6-dimethoxyacetophenone was isolated from the leaves of the Peperomia glabella (Piperaceae family). The molecule crystallizes in the space group P1 with two independent molecules in the asymmetric unit. The structural analysis reveals an infinite two-dimensional network in the (011) plane, stabilized by intermolecular hydrogen bonds along [100] and van der Waals interactions along [011]. The molecules present strong intra-molecular hydrogen bonds [O1-HO1...O4 = 1.53(2) Å and O5-HO5...O8 = 1.38(2) Å]. The molecular conformation was analyzed using the MOGUL, a knowledge base of molecular geometry derived from the CSD (Cambridge Structural Database).

Several natural compounds have been identified for the treatment of leishmaniasis. Among them are some alkaloids, chalcones, lactones, tetralones, and saponins. The new compound reported here, 7-geranyloxycoumarin, called aurapten, belongs to the chemical class of the coumarins and has a molecular weight of 298.37. The compund was extracted from the Rutaceae species Esenbeckia febrifuga and was purified from a hexane extract starting from 407.7 g of dried leaves and followed by four silica gel chromatographic fractionation steps using different solvents as the mobile phase. The resulting compound (47 mg) of shows significant growth inhibition with an LD50 of 30 µM against the tropical parasite Leishmania major, which causes severe clinical manifestations in humans and is endemic in the tropical and subtropical regions. In the present study, we investigated the atomic structure of aurapten in order to determine the existence of common structural motifs that might be related to other coumarins and potentially to other identified inhibitors of Leishmania growth and viability. This compound has a comparable inhibitory activity of other isolated molecules. The aurapten is a planar molecule constituted of an aromatic system with electron delocalization. A hydrophobic side chain consisting of ten carbon atoms with two double bonds and negative density has been identified and may be relevant for further compound synthesis.