The synthesis and characterization of two dinuclear complexes, namely fac-hexacarbonyl-1κC,2κC-(pyridine-1κN)[μ-2,2'-sulfanediyldi(ethanethiolato)-1κS,S:2κS,S,S]dirhenium(I), [Re(CHS)(CHN)(CO)], (1), and tetraethylammonium fac-tris(μ-2-methoxybenzenethiolato-κS:S)bis[tricarbonylrhenium(I)], (CHN)[Re(CHOS)(CO)], (2), together with two mononuclear complexes, namely (2,2'-bithiophene-5-carboxylic acid-κS,S')bromidotricarbonylrhenium(I), (3), and bromidotricarbonyl(methyl benzo[b]thiophene-2-carboxylate-κO,S)rhenium(I), (4), are reported. Crystals of (1) and (2) were characterized by X-ray diffraction. The crystal structure of (1) revealed two Re-S-Re bridges.
View Article and Find Full Text PDFNano scanning Auger microscopy (NanoSAM) and time-of-flight secondary ion mass spectrometry (TOF-SIMS) have been used in materials science research for some time, but NanoSAM, in particular, has only recently been applied to biological specimens. Here, the first concurrent utilization of NanoSAM, TOF-SIMS and microscopic techniques for the examination of a standard beverage fermentation strain of Saccharomyces pastorianus uncovered the presence of intracellular networks of CO2 in fermenting cells. Respiring cells produced few bubbles and instead had large internal vacuolar structures.
View Article and Find Full Text PDFWe report on the synthesis of multifunctional Ag-TiO2 nanocomposites and their optical, physio-chemical, surface enhanced Raman scattering (SERS) and antibacterial properties. A series of Ag-TiO2 nanocomposites were synthesized by sol-gel technique and characterized by x-ray diffraction, scanning and transmission electron microscopy, energy-dispersed x-ray analysis, photoluminescence, UV-vis, x-ray photoelectron and Raman spectroscopy and Brunauer-Emmett-Teller method. The Ag nanoparticles (NPs) (7-20 nm) were found to be uniformly distributed around and strongly attached to TiO2 NPs.
View Article and Find Full Text PDFCandida albicans is commonly found in mixed infections with Pseudomonas aeruginosa, especially in the lungs of cystic fibrosis (CF) patients. Both of these opportunistic pathogens are able to form resistant biofilms and frequently infect immunocompromised individuals. The interaction between these two pathogens, which includes physical interaction as well as secreted factors, is mainly antagonistic.
View Article and Find Full Text PDFWe previously reported on a 3-hydroxy fatty acid that is secreted via cryptococcal capsular protuberances - possibly to promote pathogenesis and survival. Thus, we investigated the role of this molecule in mediating the fate of Cryptococcus (C.) neoformans and the related species C.
View Article and Find Full Text PDFIn 2010, we developed a new imaging nanotechnology called Auger-architectomics, to study drug biosensors in nano-detail. We succeeded in applying Auger atom electron physics coupled to scanning electron microscopy (SEM) and Argon-etching to cell structure exploration, thereby exposing a new dimension in structure and element composition architecture. Auger-architectomics was used to expose the fate and effect of drugs on cells.
View Article and Find Full Text PDFAccording to literature, the elongated ascospores of Dipodascopsis uninucleata var. uninucleata exhibit smart movement when forcefully ejected from bottle-shaped asci. This type of movement is defined as the unique patterns of non-random movement of ascospores with specialized morphology thereby facilitating release from asci.
View Article and Find Full Text PDFIn this study the mitochondrion is regarded as a target to reveal compounds that may be used to combat various diseases. Consequently, the sexual structures of yeasts (with high mitochondrial activity) were identified as sensors to screen for various anti-mitochondrial drugs that may be toxic to humans and that are directed, amongst others, against fungal diseases and cancer. Strikingly, these sensors indicated that chloroquine is a potent pro-mitochondrial drug which stimulated yeast sexual reproduction.
View Article and Find Full Text PDFCurrent paradigms assume that gas bubbles cannot be formed within yeasts although these workhorses of the baking and brewing industries vigorously produce and release CO(2) gas. We show that yeasts produce gas bubbles that fill a significant part of the cell. The missing link between intracellular CO(2) production by glycolysis and eventual CO(2) release from cells has therefore been resolved.
View Article and Find Full Text PDFExpert Opin Drug Discov
June 2011
Introduction: New targets and drugs are constantly searched for to effectively combat fungal infections and diseases such as cancer. Mitochondria, as the main powerhouses of eukaryotic cells, must be regarded as important targets for the development of new therapies. This has lead to the development of a fungal assay that shows potential in the selection of new antifungal and anticancer drugs as well as the identification of compounds that are toxic to human mitochondria.
View Article and Find Full Text PDFThe oleaginous fungi Cryptococcus curvatus and Mucor circinelloides were used to determine the effect of palm oil breakdown products, measured as polymerized triglycerides (PTGs), on lipid turnover and on fungal growth and morphology. In M. circinelloides, we found after 7 days of growth, a decrease in biomass and in lipid utilization and accumulation at increased PTG levels, both at low and neutral pH.
View Article and Find Full Text PDFIt is known that acetylsalicylic acid, an anti-inflammatory and anti-mitochondrial drug, targets structure development and functions of yeasts depending on elevated levels of mitochondrial activity. Using antibody probes, we previously reported that sporangia of Mucor circinelloides also contain increased mitochondrial activity, yielding high levels of 3-hydroxyoxylipins. This was, however, not found in Mortierella alpina (subgenus Mortierella).
View Article and Find Full Text PDFCurr Drug Discov Technol
September 2009
Previous studies show that acetylsalicylic acid (aspirin) at low concentrations affects yeast sexual structure development in a similar fashion than oxygen depletion. This is ascribed to its anti-mitochondrial action. In this study, we report the same for other anti-inflammatory (i.
View Article and Find Full Text PDFAn increase in mitochondrial membrane potential (DeltaPsim) and mitochondrially produced 3-hydroxy (3-OH) oxylipins was experienced in asci of the nonfermentative yeasts Galactomyces reessii and Lipomyces starkeyi and the fermentative yeasts Pichia farinosa and Schizosaccharomyces octosporus. Strikingly, asci of Zygosaccharomyces bailii showed no increase in mitochondrial activity (DeltaPsim and oxylipin production). As expected, oxygen deprivation only inhibited ascus formation in those yeasts with increased ascus mitochondrial activity.
View Article and Find Full Text PDFWhen oxylipin and mitochondrion probes, i.e., fluorescing antibodies specific for 3-hydroxy fatty acids (3-OH oxylipins) and rhodamine 123 (Rh123), were added to yeast cells, these probes accumulated mainly in the sexual cells (i.
View Article and Find Full Text PDFUsing a well tested antibody specific for 3-hydroxy oxylipins, we mapped the presence of these oxylipins in selected Cryptococcus (Filobasidiella) species. Immunofluorescence microscopy studies revealed that these compounds are deposited on cell wall surfaces, appendages, and collarettes. In vitro studies revealed that growth of Cryptococcus species was inhibited by acetylsalicylic acid (which is known to inhibit mitochondrial function, including the production of 3-hydroxy oxylipins) at concentrations as low as 1 mmol/L.
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