73 resultados para Ruthenium.


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Pós-graduação em Química - IQ

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The invention relates to the synthesis and characterisation of ruthenium(II) phosphine complexes containing picolinate and/or diimine and/or biphosphine ions and having an outstanding pharmacological activity for inhibiting the growth of tuberculosis mycobacteria. These complexes can first be used in the chemical industry, and in the medium and long term, in the pharmaceutical industry. The invention also describes how the activity against tuberculosis bacillus was determined, and how the toxicity of the complexes against macrophage cells within which the tuberculosis bacillus grows was assessed.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Despite the resistance developed by the Mycobacterium tuberculosis (MTb) strains, isoniazid (INK) has been recognized as one of the best drug for treatment of Tuberculosis (Tb). The coordination of INH to ruthenium metal centers was investigated as a strategy to enhance the activity of this drug against the sensitive and resistant strains of MTb. The complexes trans-[Ru(NH3)(4)(L)(INH)](2+) (L = SO2 or NH3) were isolated and their chemical and antituberculosis properties studied. The minimal inhibitory concentration (MIC) data show that [Ru(NH3)(5)(INH)](2+) was active in both resistant and sensitive strains, whereas free INK (non-coordinated) showed to be active only against the sensitive strain. The coordination of INH to the metal center in both [Ru(NH3)(5)(INH)](2+) and trans-[Ru(NH3)(4)(SO2)(INH)](2+) complexes led to a shift in the INH oxidation potential to less positive values compared to free INH. Despite, the ease of oxidation of INH did not lead to an increase in the in vitro INH activity against MTb, it might have provided sensitivity toward resistant strains. Furthermore, ruthenium complexes with chemical structures analogous to those described above were synthesized using the oxidation products of INK as ligands (namely, isonicotinic acid and isonicotinamide). These last compounds were not active against any strains of MTb. Moreover, according to DFT calculations the formation of the acyl radical, a proposed intermediate in the INH oxidation, is favored in the [Ru(NH3)(5)(INH)](2+) complex by 50.7 kcal mol(-1) with respect to the free INH. This result suggests that the stabilization of the acyl radical promoted by the metal center would be a more important feature than the oxidation potential of the INH for the antituberculosis activity against resistant strains. (C) 2015 Elsevier B.V. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The mandibular condyle from 20-day-old rats was examined in the electron microscope with particular attention to intracellular secretory granules and extracellular matrix. Moreover, type II collagen was localized by an immunoperoxidase method. The condyle has been divided into five layers: (1) the most superficial, articular layer, (2) polymorphic cell layer, (3) flattened cell layer, (4) upper hypertrophic, and (5) lower hypertrophic cell layers. In the articular layer, the cells seldom divide, but in the polymorphic layer and upper part of the flattened cell layer, mitosis gives rise to new cells. In these layers, cells produce two types of secretory granules, usually in distinct stacks of the Golgi apparatus; type a, cylindrical granules, in which 300-nm-long threads are packed in bundles which appear lucent after formaldehyde fixation; and type b, spherical granules loaded with short, dotted filaments. The matrix is composed of thick banded lucent fibrils in a loose feltwork of short, dotted filaments. The cells arising from mitosis undergo endochondral differentiation, which begins in the lower part of the flattened cell layer and is completed in the upper hypertrophic cell layer; it is followed by gradual cell degeneration in the lower hypertrophic cell layer. The cells produce two main types of secretory granules: type b as above; and type c, ovoid granules containing 300-nm-long threads associated with short, dotted filaments. A possibly different secretory granule, type d, dense and cigar-shaped, is also produced. The matrix is composed of thin banded fibrils in a dense feltwork. In the matrix of the superficial layers, the lucency of the fibrils indicated that they were composed of collagen I, whereas the lucency of the cylindrical secretory granules suggested that they transported collagen I precursors to the matrix. Moreover, the use of ruthenium red indicated that the feltwork was composed of proteoglycan; the dotted filaments packed in spherical granules were similar to, and presumably the source of, the matrix feltwork. The superficial layers did not contain collagen II and were collectively referred to as perichondrium. In the deep layers, the ovoid secretory granules displayed collagen II antigenicity and were likely to transport precursors of this collagen to the matrix, where it appeared in the thin banded fibrils. That these granules also carried proteoglycan to the matrix was suggested by their content of short dotted filaments. Thus the deep layers contained collagen II and proteoglycan as in cartilage; they were collectively referred to as the hyaline cartilage region.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Pain is one of the most common reasons for patients to seek medical care. Bee Apis mellifera venom (AMV) has traditionally been used to treat inflammatory diseases and the alleviation of pain. Herein, we aimed to investigate the visceral antinociceptive potential of A. mellifera bee venom and its possible mechanism of action. Acetic acid-induced writhing assay was used in mice to determine the degree of visceral antinociception. Visceral antinociceptive activity was expressed as the reduction in the number of abdominal constrictions. Mice received an intraperitoneal injection of acetic acid after administration of AMV (0.08 or 0.8 mg/kg; intraperitoneally (i.p.)). In mechanistic studies, separate experiments were realized to examine the role of α2-receptors, nitric oxide, calcium channels, K+ATP channel activation, TRPV1 and opioid receptors on the visceral antinociceptive effect of AMV (0.8 mg/kg), using appropriate antagonists, yohimbine (2 mg/kg), L-NG-Nitroarginine methyl ester (L-NAME, 10 mg/kg), verapamil (5 mg/kg), glibenclamide (5 mg/kg), ruthenium red (3 mg/kg) or naloxone (2 mg/kg). AMV presented visceral antinociceptive activity in both doses tested (0.08 and 0.8 mg/Kg). Visceral antinociceptive effect of AMV was resistant to all the antagonists used. Mice showed no significant alterations in locomotion frequency, indicating that the observed antinociception is not a consequence of motor abnormality. Although AMV efficient diminished the acetic acid-evoked pain-related behavior, its mechanism is unclear from this study and future studies are needed to verify how the venom exerts its antinociceptive action.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)