26 research outputs found
Improving anti-trypanosomal activity of alkamides isolated from Achillea fragrantissima
In previous studies the aerial parts of Achillea fragrantissima were found to have substantial antileishmanial and
antitrypanosomal activity. A bioassay-guided fractionation of a dichloromethane extract yielded the isolation of
the essential anti-trypanosomal compounds of the plant. Seven sesquiterpene lactones (including Achillolide-A),
two flavonoids, chrysosplenol-D and chrysosplenetine, and four alkamides (including pellitorine) were identified.
This is the first report for the isolation of the sesquiterpene lactones 3 and 4, chrysosplenetine and the group
of alkamides from this plant. Bioevaluation against Trypanosoma brucei brucei TC221 (T.b brucei) using the
Alamar-Blue assay revealed the novel alkamide 13 to have an IC50 value of 40.37 ÎĽM. A compound library,
derived from the alkamide pellitorine (10), was synthesized and bioevaluated in order to find even more active
substances. The most active compounds 26 and 27 showed activities in submicromolar concentrations and selectivity
indices of 20.1 and 45.6, respectively, towards macrophage cell line J774.1. Toxicity of 26 and 27 was
assessed using the greater wax moth Galleria mellonella larvae as an in vivo model. No significant toxicity was
observed for the concentration range of 1.25–20 mM.We thank Dr. Ulrich Hildebrandt and Dr. Gerd Vogg, Botanical
garden, University of WĂĽrzburg, for identifying the seeds and plants of
A. fragrantissima. We are grateful to Prof. Dr. August Stich, Medical
Mission Institute, University of WĂĽrzburg, for providing the respective
lab facilities to perform the anti-trypanosomal assay. Many thanks for
Dr. Ludwig Hoellein for proof-reading the manuscript. We wish to
thank the German Academic Exchange Service (DAAD) for the doctoral
scholarship of Joseph Skaf (grant number: 57169181). Srikkanth
Balasubramanian was supported by a grant of the German Excellence
Initiative to the Graduate School of Life Sciences, University of
WĂĽrzburg
A New Bioactive Compound From the Marine Sponge-Derived Streptomyces sp. SBT348 Inhibits Staphylococcal Growth and Biofilm Formation
Staphylococcus epidermidis, the common inhabitant of human skin and mucosal surfaces has emerged as an important pathogen in patients carrying surgical implants and medical devices. Entering the body via surgical sites and colonizing the medical devices through formation of multi-layered biofilms leads to refractory and persistent device-related infections (DRIs). Staphylococci organized in biofilms are more tolerant to antibiotics and immune responses, and thus are difficult-to-treat. The consequent morbidity and mortality, and economic losses in health care systems has strongly necessitated the need for development of new anti-bacterial and anti-biofilm-based therapeutics. In this study, we describe the biological activity of a marine sponge-derived Streptomyces sp. SBT348 extract in restraining staphylococcal growth and biofilm formation on polystyrene, glass, medically relevant titan metal, and silicone surfaces. A bioassay-guided fractionation was performed to isolate the active compound (SKC3) from the crude SBT348 extract. Our results demonstrated that SKC3 effectively inhibits the growth (MIC: 31.25 μg/ml) and biofilm formation (sub-MIC range: 1.95–<31.25 μg/ml) of S. epidermidis RP62A in vitro. Chemical characterization of SKC3 by heat and enzyme treatments, and mass spectrometry (HRMS) revealed its heat-stable and non-proteinaceous nature, and high molecular weight (1258.3 Da). Cytotoxicity profiling of SKC3 in vitro on mouse fibroblast (NIH/3T3) and macrophage (J774.1) cell lines, and in vivo on the greater wax moth larvae Galleria mellonella revealed its non-toxic nature at the effective dose. Transcriptome analysis of SKC3 treated S. epidermidis RP62A has further unmasked its negative effect on central metabolism such as carbon flux as well as, amino acid, lipid, and energy metabolism. Taken together, these findings suggest a potential of SKC3 as a putative drug to prevent staphylococcal DRIs
Operation and performance of the ATLAS semiconductor tracker in LHC Run 2
The semiconductor tracker (SCT) is one of the tracking systems for charged particles in the ATLAS detector. It consists of 4088 silicon strip sensor modules. During Run 2 (2015–2018) the Large Hadron Collider delivered an integrated luminosity of 156 fb-1 to the ATLAS experiment at a centre-of-mass proton-proton collision energy of 13 TeV. The instantaneous luminosity and pile-up conditions were far in excess of those assumed in the original design of the SCT detector. Due to improvements to the data acquisition system, the SCT operated stably throughout Run 2. It was available for 99.9% of the integrated luminosity and achieved a data-quality efficiency of 99.85%. Detailed studies have been made of the leakage current in SCT modules and the evolution of the full depletion voltage, which are used to study the impact of radiation damage to the modules
Antileishmanien- und Antitrypanosomen-Wirkstoffe aus
This PhD thesis is dealing with the bioassay-guided fractionation of a dichloromethane extract of the aerial parts of Achillea fragrantissima with the aim of isolation and structure isolation of the antileishmanial and/or antitrypanosomal principles in the plant.Diese Dissertation beschäftigt sich mit der aktivitätsgeleiteten Fraktionierung eines Dichlormethanextrakts aus den oberirdischen Teilen von Achillea fragrantissima mit dem Ziel der Isolierung und Strukturaufklärung der anti-leishmanialen und/oder anti-trypanosomalen Verbindungen der Pflanze
Diel Mediated Populus balsamifera Transcriptome Components Test the Impacts of Artificial Nighttime Lighting
Artificial nighttime lighting (ANL) is known to adversely affect animals, but little is known what the consequences are to plants. Two genotypes of Populus balsamifera, a common urban tree, were used to investigate how ANL impacts plants. While the two genotypes varied in their physiological sensitivity to ANL, poorer levels of net leaf carbon assimilation compared to control samples suggested that ANL perturbed the perception of time of day for these plants. Gene set analysis on a subset of PopGenExpress microarray samples identified time of day specific processes in P. balsamifera, and a set of candidate ANL-sensitive genes were identified from these. Transcript measurements from the two genotypes revealed that ANL affects plants at the molecular level, for the diel cycling of the putative ANL-sensitive genes was perturbed. Together, these results suggest that ANL affects plants at the physiological and molecular level by perturbing their perception of time of day.MAS
Transcatheter Reduction of Paravalvular Leaks: A Systematic Review and Meta-analysis
Background: Significant paravalvular leak (PVL) after surgical valve replacement can result in intractable congestive heart failure and hemolytic anemia. Because repeat surgery is performed in only few patients, transcatheter reduction of PVL is emerging as an alternative option, but its safety and efficacy remain uncertain. In this study we sought to assess whether a successful transcatheter PVL reduction is associated with an improvement in clinical outcomes. Methods: We identified 12 clinical studies that compared successful and failed transcatheter PVL reductions in a total of 362 patients. A Bayesian hierarchical meta-analysis was performed using cardiac mortality as a primary end point. The combined occurrence of improvement in New York Heart Association functional class or hemolytic anemia and the need for repeat surgery, were used as secondary end points. Results: A successful transcatheter PVL reduction was associated with a lower cardiac mortality rate (odds ratio [OR], 0.08; 95% credible interval [CrI], 0.01-0.90) and with a superior improvement in functional class or hemolytic anemia, compared with a failed intervention (OR, 9.95; 95% CrI, 2.10-66.73). Fewer repeat surgeries were also observed after successful procedures (OR, 0.08; 95% CrI, 0.01-0.40). Conclusions: A successful transcatheter PVL reduction is associated with reduced all-cause mortality and improved functional class in patients deemed unsuitable for surgical correction
Data_Sheet_1_A New Bioactive Compound From the Marine Sponge-Derived Streptomyces sp. SBT348 Inhibits Staphylococcal Growth and Biofilm Formation.docx
<p>Staphylococcus epidermidis, the common inhabitant of human skin and mucosal surfaces has emerged as an important pathogen in patients carrying surgical implants and medical devices. Entering the body via surgical sites and colonizing the medical devices through formation of multi-layered biofilms leads to refractory and persistent device-related infections (DRIs). Staphylococci organized in biofilms are more tolerant to antibiotics and immune responses, and thus are difficult-to-treat. The consequent morbidity and mortality, and economic losses in health care systems has strongly necessitated the need for development of new anti-bacterial and anti-biofilm-based therapeutics. In this study, we describe the biological activity of a marine sponge-derived Streptomyces sp. SBT348 extract in restraining staphylococcal growth and biofilm formation on polystyrene, glass, medically relevant titan metal, and silicone surfaces. A bioassay-guided fractionation was performed to isolate the active compound (SKC3) from the crude SBT348 extract. Our results demonstrated that SKC3 effectively inhibits the growth (MIC: 31.25 μg/ml) and biofilm formation (sub-MIC range: 1.95–<31.25 μg/ml) of S. epidermidis RP62A in vitro. Chemical characterization of SKC3 by heat and enzyme treatments, and mass spectrometry (HRMS) revealed its heat-stable and non-proteinaceous nature, and high molecular weight (1258.3 Da). Cytotoxicity profiling of SKC3 in vitro on mouse fibroblast (NIH/3T3) and macrophage (J774.1) cell lines, and in vivo on the greater wax moth larvae Galleria mellonella revealed its non-toxic nature at the effective dose. Transcriptome analysis of SKC3 treated S. epidermidis RP62A has further unmasked its negative effect on central metabolism such as carbon flux as well as, amino acid, lipid, and energy metabolism. Taken together, these findings suggest a potential of SKC3 as a putative drug to prevent staphylococcal DRIs.</p
Table_2_A New Bioactive Compound From the Marine Sponge-Derived Streptomyces sp. SBT348 Inhibits Staphylococcal Growth and Biofilm Formation.xlsx
<p>Staphylococcus epidermidis, the common inhabitant of human skin and mucosal surfaces has emerged as an important pathogen in patients carrying surgical implants and medical devices. Entering the body via surgical sites and colonizing the medical devices through formation of multi-layered biofilms leads to refractory and persistent device-related infections (DRIs). Staphylococci organized in biofilms are more tolerant to antibiotics and immune responses, and thus are difficult-to-treat. The consequent morbidity and mortality, and economic losses in health care systems has strongly necessitated the need for development of new anti-bacterial and anti-biofilm-based therapeutics. In this study, we describe the biological activity of a marine sponge-derived Streptomyces sp. SBT348 extract in restraining staphylococcal growth and biofilm formation on polystyrene, glass, medically relevant titan metal, and silicone surfaces. A bioassay-guided fractionation was performed to isolate the active compound (SKC3) from the crude SBT348 extract. Our results demonstrated that SKC3 effectively inhibits the growth (MIC: 31.25 μg/ml) and biofilm formation (sub-MIC range: 1.95–<31.25 μg/ml) of S. epidermidis RP62A in vitro. Chemical characterization of SKC3 by heat and enzyme treatments, and mass spectrometry (HRMS) revealed its heat-stable and non-proteinaceous nature, and high molecular weight (1258.3 Da). Cytotoxicity profiling of SKC3 in vitro on mouse fibroblast (NIH/3T3) and macrophage (J774.1) cell lines, and in vivo on the greater wax moth larvae Galleria mellonella revealed its non-toxic nature at the effective dose. Transcriptome analysis of SKC3 treated S. epidermidis RP62A has further unmasked its negative effect on central metabolism such as carbon flux as well as, amino acid, lipid, and energy metabolism. Taken together, these findings suggest a potential of SKC3 as a putative drug to prevent staphylococcal DRIs.</p