RESUMO

Coordination complexes may act as anticancer agents. Among others, the formation of the complex may facilitate the ligand uptake by the cell. Searching for new copper compounds with cytotoxic activity, the complex Cu-dipicolinate was studied as a neutral scaffold to form ternary complexes with diimines. A series of [Cu(dipicolinate)(diimine)] complexes (where diimine: Phenanthroline, phen, 5-NO2-phenanthroline, 4-methyl-phenanthroline, neocuproine, 3,4,7,8-tetramethyl-phenanthroline, tmp, bathophenanthroline, bipyridine, dimethyl-bipyridine, as well as the ligand 2,2-dipyridil-amine, bam) were synthesized and characterized both in the solid state, including a new crystal structure of [Cu2(dipicolinate)2(tmp)2]·7H2O. Their chemistry in aqueous solution was explored by UV/vis spectroscopy, conductivity, cyclic voltammetry, and electron paramagnetic resonance studies. Their DNA binding was analyzed by electronic spectroscopy (determining Kb values), circular dichroism, and viscosity methods. The cytotoxicity of the complexes was assessed on human cancer cell lines MDA-MB-231, MCF-7 (breast, the first triple negative), A549 (lung epithelial) and A2780cis (ovarian, Cisplatin-resistant), and non-tumor cell lines MRC-5 (lung) and MCF-10A (breast). The major species are ternary, in solution and solid state. Complexes are highly cytotoxic as compared to Cisplatin. Complexes containing bam and phen are interesting candidates to study their in vivo activity in triple-negative breast cancer treatment.

RESUMO

Previous studies have shown that the combination disinfectant, Ortho-phthalaldehyde and benzyldimethyldodecylammonium chloride (ODB), can effectively kill a variety of microorganisms, such as Escherichia coli, Staphylococcus aureus, and Candida albicans. To observe the sporicidal ability and mechanism of ODB for spores, Bacillus subtilis spores were used as the research object in this experiment. TEM images revealed that ODB destroyed the integrity of the coat, cortex, and inner membrane of the spores after 0.5-h treatment, and the nuclear material was also broken and exuded after 4-h treatment. The broken structure led to the release of dipicolinic acid (DPA) in large amount. The results show that B. subtilis spores can be effetely killed by ODB through destroying the structure of the spores.

Assuntos

RESUMO

Composition of the immobilized layer plays a crucial role in metal adsorption properties of complexing organo-mineral materials. Ignoring the specific features of chemical reactions on solid surface can lead to a significant deterioration in the target properties of the resulted materials. In this research we demonstrated that rationally designed surface-assembling synthesis of organo-silica with covalently immobilized fragments of dipicolinic acid (DPA) resulted in the adsorbent that is capable quantitively recover almost all Rare Earth elements (REEs) from multielement solution with pH > 1.7. In ten consecutive adsorption/desorption cycles no noticeable loss of its efficiency was found, with a mean value of REEs recovery larger than 97%. The adsorbent has been used to recover REEs from model solutions (22 metal ions in 0.5 mol L-1 NaCl) and real leaching solution of waste of fluorescent lamps. It was demonstrated that even 3200-fold excess of Fe and Cu ions only slightly reduces REEs recovery. The adsorbent is capable to recover above 80% of all (except La) REEs from acidic leaching solution from fluorescent lamps with enrichment factors above 600. After adsorption of Eu3+ and Tb3+, the resulting materials exhibited strong red and green luminescence, respectively, indicating chelating mechanism of REEs adsorption on SiO2-DPA.

RESUMO

In the last 30 years, since the discovery that vanadium is a cofactor found in certain enzymes of tunicates and possibly in mammals, different vanadium-based drugs have been developed targeting to treat different pathologies. So far, the in vitro studies of the insulin mimetic, antitumor and antiparasitic activity of certain compounds of vanadium have resulted in a great boom of its inorganic and bioinorganic chemistry. Chemical speciation studies of vanadium with amino acids under controlled conditions or, even in blood plasma, are essential for the understanding of the biotransformation of e.g. vanadium antidiabetic complexes at the physiological level, providing clues of their mechanism of action. The present article carries out a bibliographical research emphaticizing the chemical speciation of the vanadium with different amino acids and reviewing also some other important aspects such as its chemistry and therapeutical applications of several vanadium complexes.

RESUMO

Pseudomonas aeruginosa es uno de los patógenos oportunistas más importantes, causante de infecciones, con altos índices de morbilidad y mortalidad. Los carbapenemes son antibióticos que poseen un amplio espectro de actividad y son altamente potentes, lo cual hacen que sean imprescindibles en el tratamiento empírico. P. aeruginosa presenta diversos mecanismos de resistencia, entre ellos las carbapenemasas tipo metalo-β-lactamasas (MBLs). Debido a los numerosos reportes de bacterias productoras de MBLs, es importante la aplicación de test simples, prácticos y de bajo costo, como pruebas de rutina, para que se pueda identificar a las bacterias productoras de MBLs de forma rápida. El objetivo de este trabajo es determinar fenotípicamente la presencia de carbapenemasas en aislamientos de P. aeruginosa. Estudio prospectivo, descriptivo de corte transversal realizado en aislamientos de P. aeruginosa de pacientes que acudieron al Hospital de Clínicas - San Lorenzo en el periodo de febrero a julio de 2013. Se estudiaron 232 aislamientos de P. aeruginosa, a aquellos con sospecha de carbapenemasas se les aplicó dos métodos de detección fenotípica, discos de EDTA y discos con ácido dipicolinico - Meropenem (DPA-ME). De estos aislamientos, 30 dieron sinergia con la técnica de EDTA y 18 aislamientos positivos con los discos de DPA. A través de los métodos fenotípicos aplicados se pudo comprobar la presencia de cepas productoras de carbapenemasas tipo MBL en una frecuencia de 7,8%. Los tests de combinación de disco podrían ser útiles en la práctica diaria para proporcionar una detección rápida y fiable de MBL carbapenemasas en los aislados de P. aeruginosa cuando las pruebas moleculares no están disponibles.

P. aeruginosa is one of the most important opportunistic pathogens that cause infections with high morbidity and mortality. Carbapenems are antibiotics with a broad spectrum of activity and highly powerful, which makes them indispensable in the empirical treatment. P. aeruginosa has various mechanisms of resistance, including metallobetalactamase (MBL) type carbapenemases. Due to increasing numbers of MBL producing bacteria, it is important to apply simple tests that are practical and inexpensiveas routine protocol in order to rapidly identify MBL producing bacteria. The objective ofthis study was to determine phenotypically the presence of carbapenemases in P aeruginosa isolates. A descriptive cross- sectional study was performed in isolates of P.aeruginosa from patients attending the Hospital de Clinicas - San Lorenzo from February to July, 2013. Two hundred thirty two isolates of P. aeruginosa were studied. Those isolates suspicious of having Carbapenemases were subjected to two phenotypic detection methods: discs of EDTA and discs of dipicolinic acid – Meropenem (DPA-ME). Of these isolates, 30 were synergistic with the technique of EDTA and 18 positive with DPA discs.The presence of strains producing MBL type carbapenemases was determined throughthese phenotypic methods yielding a frequency of 7.8%. The disc combination tests maybe very useful in the daily practice to provide fast and reliable detection of MBL carbapenemases in P. aeruginosa isolates, where molecular biology tests are not available.

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