From Simple Palladium(II) Monomers to 2D Heterometallic Sodium-Palladium(II) Coordination Networks with 2-Halonicotinates.

The 2D heterometallic sodium-palladium(II) coordination polymers with 2-halonicotinates [2-chloropyridine-3-carboxylate (2-chloronicotinate), 2-Clnic- and 2-bromopyridine-3-carboxylate (2-bromonicotinate), 2-Brnic-], {[Na2(H2O)2(µ-H2O)4PdCl2(µ-2-Clnic-N:O')2]}n (1), and {[Na2(H2O)2(µ-H2O)4PdBr2(µ-2-Brnic-N:O')2]·2H2O}n (2) were prepared in aqueous solutions under the presence of NaHCO3, while palladium(II) monomers with the neutral 2-chloronicotinic and 2-bromonicotinic acid ligands, [PdCl2(2-ClnicH-N)2]·2DMF (3) and [PdCl2(2-BrnicH-N)2]·2DMF (4), were prepared in DMF/water mixtures (DMF = N,N'-dimethylformamide). The zigzag chains of water-bridged sodium ions are in turn bridged by [PdCl2(2-Clnic)2]2- moieties in 1 or by [PdBr2(2-Brnic)2]2- moieties in 2, leading to the formation of the infinite 2D coordination networks of 1 or 2. The DFT calculations showed the halosubstituents type (Cl vs Br) does not have an influence on the formation of either trans or cis isomers. The trans isomers were found in all reported compounds; being more stable for about 10 to 15 kJ mol-1. The 2D coordination networks 1 and 2 are more stabilized by the formation of Na-Ocarboxylate bonds, comparing to the stabilization of palladium(II) monomers 3 and 4 by hydrogen-bonding with DMF molecules. The difference in DFT calculated energy stabilization for 1 and 2 is ascribed to the type of halosubstituents and to the presence/absence of lattice water molecules in 1 and 2. The compounds show no antibacterial activity toward reference strains of Escherichia coli and Staphylococcus aureus bacteria and no antiproliferative activity toward bladder (T24) and lung (A549) cancer cell lines.

Revisiting the absolute chirality and polymorphism of (-)-Istanbulin A.

The terpenoid (-)-Istanbulin A is a natural product isolated from Senecio filaginoides DC, one of the 270 species of Senecio (Asteraceae) which occurs in Argentina. The structure and absolute configuration of this compound [9a-hydroxy-3,4a,5-trimethyl-4a,6,7,8a,9,9a-hexahydro-4H,5H-naphtho[2,3-b]-furan-2,8-dione or (4S,5R,8R,10S)-1-oxo-8ß-hydroxy-10ßH-eremophil-7(11)-en-12,8ß-olide, C15H20O4] were determined by single-crystal X-ray diffraction studies. It proved to be a sesquiterpene lactone showing an eremophilanolide skeleton whose chirality is described as 4S,5R,8R,10S. Structural results were also in agreement with the one- and two-dimensional (1D and 2D) NMR and HR-ESI-MS data, and other complementary spectroscopic information. In addition, (-)-Istanbulin A is a polymorph of the previously reported form of (-)-Istanbulin A, form I; thus, the title compound is denoted form II or polymorph II. Structural data and a literature search allowed the chirality of Istanbulin A to be revisited. The antimicrobial and antifungal activities of (-)-Istanbulin A, form II, were evaluated in order to establish a reference for future comparisons and applications related to specific crystal forms of Istanbulins.

Bispecific antibody process development: Assembly and purification of knob and hole bispecific antibodies.

Production of knob and hole dual light chain bispecific antibodies poses several unique challenges for development of a feasible industrial scale manufacturing process. We developed an efficient process for the assembly and purification of knob and hole dual light chain bispecific antibodies. Two distinct half-antibodies targeting two different antigens were expressed separately in Escherichia coli cells and captured independently using Protein A chromatography. When combined, the knob and hole mutations in the CH3 domains promoted heterodimer formation. The hinge region disulfides were reduced and reoxidized to form the disulfide bridge between the two complementary half antibodies. Unreacted half antibodies, noncovalently linked homodimers, covalently linked homodimers, and noncovalently linked heterodimers are impurities closely related to the product of interest and are challenging to remove by standard processes. Characterization of the molecular properties of the half antibodies and high-throughput screening predicted column chromatography performance and allowed for rapid development of downstream purification steps for removal of unique product-related and process-related impurities. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:397-404, 2018.

Selenium-containing analogues of WC-9 are extremely potent inhibitors of Trypanosoma cruzi proliferation.

The obligate intracellular parasite, Trypanosoma cruzi is the etiologic agent of Chagas disease or American trypanosomiasis, which is the most prevalent parasitic disease in the Americas. The present chemotherapy to control this illness is still deficient particularly in the chronic stage of the disease. The ergosterol biosynthesis pathway has received much attention as a molecular target for the development of new drugs for Chagas disease. Especially, inhibitors of the enzymatic activity of squalene synthase were shown to be effective compounds on T. cruzi proliferation in in vitro assays. In the present study we designed, synthesized and evaluated the effect of a number of isosteric analogues of WC-9 (4-phenoxyphenoxyethyl thiocyanate), a known squalene synthase inhibitor, on T. cruzi growth in tissue culture cells. The selenium-containing derivatives turned out to be extremely potent inhibitors of T. cruzi growth. Certainly, 3-phenoxyphenoxyethyl, 4-phenoxyphenoxyethyl, 4-(3-fluorophenoxy)phenoxyethyl, 3-(3-fluorophenoxy)phenoxyethyl selenocyanates and (±)-5-phenoxy-2-(selenocyanatomethyl)-2,3-dihydrobenzofuran arose as relevant members of this family of compounds, which exhibited effective ED50 values of 0.084 µM, 0.11 µM, 0.083, µM, 0.085, and 0.075 µM, respectively. The results indicate that compounds bearing the selenocyanate moiety are at least two orders of magnitude more potent than the corresponding skeleton counterpart bearing the thiocyanate group. Surprisingly, these compounds exhibited excellent selectively index values ranging from 900 to 1800 making these molecules promising candidates as antiparasitic agents.

Synthesis, crystal structure and study of the crystal packing in the complex bis(4-aminopyridine-κN1)dichloridocobalt(II).

Despite the large number of reported crystalline structures of coordination complexes bearing pyridines as ligands, the relevance of π-π interactions among these hereroaromatic systems in the stabilization of their supramolecular structures and properties is not very well documented in the recent literature. The title compound, [CoCl2(C5H6N2)2], was obtained as bright-blue crystals suitable for single-crystal X-ray diffraction analysis from the reaction of 4-aminopyridine with cobalt(II) chloride in ethanol. The new complex was fully characterized by a variety of spectroscopic techniques and single-crystal X-ray diffraction. The crystal structure showed a tetrahedral complex stabilized mainly by bidimensional motifs constructed by π-π interactions with large horizontal displacements between the 4-aminopyridine units, and N-H...Cl hydrogen bonds. Other short contacts, such as C-H...Cl interactions, complete the three-dimensional arrangement. The supramolecular investigation was extended by statistical studies using the Cambridge Structural Database and a Hirshfeld surface analysis.

Metodología de evaluación del proceso docente educativo en la disciplina de Morfofisiología / Methodology to assess the educational process in the discipline of Morphophysiology

Fundamento: la misión de la universidad contemporánea es formar recursos humanos que respondan a las exigencias de la sociedad, por lo que resulta indispensable evaluar continuamente la calidad del proceso docente educativo. Objetivo: diseñar una metodología que permita evaluar el nivel de satisfacción de estudiantes, profesores y directivos que participan directamente en el proceso docente educativo de la disciplina Morfofisiología como indicador de calidad. Métodos: se diseñó una metodología validada por expertos y sustentada en indicadores de calidad, a nivel grupal e individual que incluye cuestionarios de opinión de estudiantes, profesores y directivos así como grupo focal en los que se analizan variables como: la planificación y ejecución del proceso, los aspectos organizativos y funcionales, el clima organizacional, calidad gerencial y trabajo educativo.Resultados: se establece la metodología para la evolución de la satisfacción de los estudiantes, de los docentes y directivos en la ejecución del proceso docente educativo en Morfofisiología como indicador de calidad del mismo, con las unidades de análisis a nivel de grupo e individual. En cada caso se definen indicadores y escala evaluativa de cada uno de ellos. Conclusiones: la metodología diseñada permite evaluar el nivel de satisfacción de estudiantes, profesores y directivos y determinar los factores que repercuten en la calidad del proceso docente educativo de la disciplina Morfofisiología(AU)

Background: the mission of the modern university is to train human resources that meet the demands of society; therefore it is essential to continually assess the quality of the educational process. Objective: to design a methodology to assess the level of satisfaction of students, professors and administrators directly involved in the educational process in the discipline of Morphophysiology as a quality indicator.Methods: a methodology validated by experts and based on quality indicators was designed at group and individual level, including opinion-based questionnaires for students, professors and administrators, as well as focus group. Variables analyzed were: planning and implementation of the process, organizational and functional aspects, organizational climate, managerial quality and educational work. Results: the methodology for assessing the satisfaction of students, professors and administrators with the implementation of the educational process in Morphophysiology as a quality indicator was established, with units of analysis at the group and individual level. In each case, indicators and scale for assessment were defined.Conclusions: the designed methodology allows assessing the level of satisfaction of students, professors and administrators, and determining the factors that affect the quality of the educational process in the discipline of Morphophysiology(AU)

Studying host cell protein interactions with monoclonal antibodies using high throughput protein A chromatography.

Protein A chromatography is typically used as the initial capture step in the purification of monoclonal antibodies produced in Chinese hamster ovary (CHO) cells. Although exploiting an affinity interaction for purification, the level of host cell proteins in the protein A eluent varies significantly with different feedstocks. Using a batch binding chromatography method, we performed a controlled study to assess host cell protein clearance across both MabSelect Sure and Prosep vA resins. We individually spiked 21 purified antibodies into null cell culture fluid generated with a non-producing cell line, creating mock cell culture fluids for each antibody with an identical composition of host cell proteins and antibody concentration. We demonstrated that antibody-host cell protein interactions are primarily responsible for the variable levels of host cell proteins in the protein A eluent for both resins when antibody is present. Using the additives guanidine HCl and sodium chloride, we demonstrated that antibody-host cell protein interactions may be disrupted, reducing the level of host cell proteins present after purification on both resins. The reduction in the level of host cell proteins differed between antibodies suggesting that the interaction likely varies between individual antibodies but encompasses both an electrostatic and hydrophobic component.

Nivel de satisfacción de los gestores del proceso docente educativo, en la disciplina Morfofisiología / Satisfaction level of managers of the educational process in morphophysiology discipline

Fundamento: la misión de la universidad contemporánea es formar recursos humanos que respondan a las exigencias de la sociedad, por lo que resulta indispensable evaluar continuamente la calidad del proceso docente educativo que se suscita hoy en estos centros docentes. Objetivo: evaluar el nivel de satisfacción de estudiantes, profesores y directivos que participan directamente en el proceso docente educativo en la disciplina Morfofisiología. Métodos: se aplica una metodología validada por expertos y compuesta por indicadores de calidad, a nivel grupal e individual que incluye la aplicación de cuestionarios de opinión a estudiantes, profesores y directivos así como grupo focal en los que se analizan variables como: la planificación yejecución del proceso, los aspectos organizativos y funcionales, el clima organizacional, la calidad gerencial y el trabajo educativo. Resultados: los indicadores que más afectan el nivel de satisfacción en el caso de los estudiantes y profesores fueron: la calidad de las conferencias orientadoras y el acceso a las tecnologías; en cuanto a los directivos: el insuficiente control y asesoría por los especialistas y metodólogos de la facultad al proceso docente-educativo. Conclusión: la metodología aplicada permite evaluar el nivel de satisfacción de estudiantes, profesores y directivos y determinar los factores que comprometen la calidad del proceso docente- educativo de la disciplina Morfofisiología(AU)

Background: to improve the quality of the educational process in Morphophysiology. Objective: to assess the satisfaction level of students, teachers and managers directly involved in the educational process inMorphophysiology. Methods: a methodology validated by experts and supported by quality indicators atindividual and group level is applied. It includes surveys for students, teachers and managers and focus group forthe analysis of variables such as planning and execution of the process, organizational and functional aspects,organizational environment, management quality and educational work. Results: the indicators that affect the satisfaction level of students and teachers are the quality of lectures and the access to technologies. As formanagers, it is the lack of control and advice by specialists and methodologists of the educationalprocess in the faculty. Conclusion: the methodology used allows assessing the satisfaction level of students, teachers and managers as well as determining thefactors that affect the quality of the educational process in Morphophysiolog(AU)