168 research outputs found

    Ammonium tri-tert-butoxy­silanethiol­ate

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    The cations and anions of the title salt, NH4 +·C12H27O3SSi−, are linked by N—H⋯S and N—H⋯O hydrogen bonds into a linear chain that runs along the a axis of the monoclinic unit cell. The asymmetric unit contains two cations and two anions

    2,2,6,6-Tetra­methyl­piperidinium triisopropoxysilanethiol­ate

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    The crystal of the title compound, C9H20N+·C9H21O3SSi−, is built of aggregates, each made up of two 2,2,6,6-tetra­methyl­piperidinium cations and two triisopropoxysilanethiol­ate anions. The aggregates are linked by four N—H⋯S bonds and correspond to an R 2 4(8) graph-set motif

    catena-Poly[[(tetra­hydro­furan-κO)lithium(I)]-bis­(μ-trimethyl­silanolato-κ2 O:O)-gallium(III)-bis­(μ-trimethyl­silanolato-κ2 O:O)-[(tetra­hydro­furan-κO)lithium(I)]-μ-bromido]

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    The title chain polymer compound, [GaLi2Br(C3H9OSi)4(C4H8O)2]n, was obtained in the reaction of GaBr3 with Me3SiOLi in toluene/tetra­hydro­furan. The GaIII atom, located on a twofold rotation axis, is coordinated by four trimethyl­silanolate ligands and has a distorted tetra­hedral geometry. The LiI atom is four coordinated by one bridging Br atom located on an inversion centre, two trimethyl­silanolate ligands and one tetra­hydro­furane mol­ecule in a distorted tetra­hedral geometry. The polymeric chains extend along [001]. The tetra­hydro­furane mol­ecule is disordered over two positions with site-occupancy factors of 0.57 (2) and 0.43 (2)

    ATP Synthase Subunit a Supports Permeability Transition in Yeast Lacking Dimerization Subunits and Modulates yPTP Conductance

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    Background/Aims: Mitochondrial ATP synthase, in addition to being involved in ATP synthesis, is involved in permeability transition pore (PTP) formation, which precedes apoptosis in mammalian cells and programmed cell death in yeast. Mutations in genes encoding ATP synthase subunits cause neuromuscular disorders and have been identified in cancer samples. PTP is also involved in pathology. We previously found that in Saccharomyces cerevisiae,two mutations in ATP synthase subunit a (atp6-P163S and atp6-K90E, equivalent to those detected in prostate and thyroid cancer samples, respectively) in the OM45-GFP background affected ROS and calcium homeostasis and delayed yeast PTP (yPTP) induction upon calcium treatment by modulating the dynamics of ATP synthase dimer/oligomer formation. The Om45 protein is a component of the porin complex, which is equivalent to mammalian VDAC. We aimed to investigate yPTP function in atp6-P163S and atp6-K90E mutants lacking the e and g dimerization subunits of ATP synthase. Methods: Triple mutants with the atp6-P163S or atp6-K90E mutation, the OM45-GFP gene and deletion of the TIM11 gene encoding subunit ewere constructed by crossing and tetrad dissection. In spores capable of growing, the original atp6 mutations reverted to wild type, and two compensatory mutations, namely, atp6-C33S-T215C, were selected. The effects of these mutations on cellular physiology, mitochondrial morphology, bioenergetics and permeability transition (PT) were analyzed by fluorescence and electron microscopy, mitochondrial respiration, ATP synthase activity, calcium retention capacity and swelling assays. Results: The atp6-C33S-T215Cmutationsin the OM45-GFPbackground led to delayed growth at elevated temperature on both fermentative and respiratory media and increased sensitivity to high calcium ions concentration or hydrogen peroxide in the medium. The ATP synthase activity was reduced by approximately 50% and mitochondrial network was hyperfused in these cells grown at elevated temperature. The atp6-C33S-T215Cstabilized ATP synthase dimers and restored the yPTP properties in Tim11∆ cells. In OM45-GFP cells, in which Tim11 is present, these mutations increased the fraction of swollen mitochondria by up to 85% vs 60% in the wild type, although the time required for calcium release doubled. Conclusion: ATP synthase subunit e is essential in the S. cerevisiaeatp6-P163S and atp6-K90E mutants. In addition to subunits e and g, subunit a is critical for yPTP induction and conduction. The increased yPTP conduction decrease the S. cerevisiae cell fitness

    Arnica montana and its medicinal value in the light of scientific research

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    Arnica montana is a plant that has been used in medicine for hundreds of years. Currently it is used in phytotherapy as topical remedies (gels, ointments, liquids with extract from dried arnica flowers) and in homeopathy, in which oral application is also allowed (various dilutions of TM tincture from fresh planta tota). The aim of this work was to summarize the literature data on the importance of arnica and its products in phytotherapy on the background of its homeopathic applications, considering the chemical composition, pharmacological and biological activity, mechanisms of action, and the results of clinical trials. The results of biochemical and pharmacological research confirm the benefits of allopathic arnica products as anti-inflammatory agents. The mechanism of action is mostly based on the presence of two groups of biologically active substances: sesquiterpene lactones – helenalin, dihydrohelenalin and their esters, as well as polyphenolic compounds that enhance their activity. Clinical trials confirm the efficacy of analyzed arnica products in the treatment of muscle-skeletal system disorders of various etiology, including both sport injuries and rheumatic disorders. Additionally, the therapeutic potential of arnica is also associated with other biological activities, especially anti-oedema, anti-rheumatic, antioxidant, and beneficial influence on blood vessels. Recently published papers report also a promising potential of arnica in other indications, including treatment of cutaneous leishmaniasis. The presented review of scientific reports indicates that A. montana products constitute a source of valuable biologically active compounds, and as a result, an effective remedy for inflammatory ailments of different etiology (sport injuries, rheumatic disorders). In addition to the well-established use of arnica as an anti-inflammatory agent, the results of recent years' research expand the therapeutic potential of the plant raw material with new possible applications and directions of action
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