35,980 research outputs found

    Determination of the Primary Molecular Target of 1,2,4-Triazole-Ciprofloxacin Hybrids

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    We have synthesized and examined the antibacterial activity, toxicity and affinity towards bacterial type II topoisomerases of a series of 1,2,4-triazole-ciprofloxacin hybrids. A number of these compounds displayed enhanced activity against Gram-positive and Gram-negative bacteria when compared to ciprofloxacin. The toxic concentrations of the obtained derivatives, evaluated on HEK-293 cells using MTT assay, were much higher than concentrations required to produce antibacterial effect. Finally, the results of enzymatic studies showed that the analyzed compounds demonstrated other preferences as regards primary and secondary molecular targets than ciprofloxacin.This research was supported by the Ministry of Science and Higher Education under Iuventus Plus grant No. IP2014 037473. Tomasz Plech is a recipient of the Fellowship for Young Researchers with Outstanding Scientific Achievements from the Medical University of Lublin (Lublin, Poland)

    Radiosynthesis, in vitro and preliminary in vivo evaluation of the novel glutamine derived PET tracers [18F]fluorophenylglutamine and [18F]fluorobiphenylglutamine

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    INTRODUCTION: Glucose has been deemed the driving force of tumor growth for decades. However, research has shown that several tumors metabolically shift towards glutaminolysis. The development of radiolabeled glutamine derivatives could be a useful molecular imaging tool for visualizing these tumors. We elaborated on the glutamine-derived PET tracers by developing two novel probes, namely [(18)F]fluorophenylglutamine and [(18)F]fluorobiphenylglutamine MATERIALS AND METHODS: Both tracers were labelled with fluorine-18 using our recently reported ruthenium-based direct aromatic fluorination method. Their affinity was evaluated with a [(3)H]glutamine inhibition experiment in a human PC-3 and a rat F98 cell line. The imaging potential of [(18)F]fluorophenylglutamine and [(18)F]fluorobiphenylglutamine was tested using a mouse PC-3 and a rat F98 tumor model. RESULTS: The radiosynthesis of both tracers was successful with overall non-decay corrected yields of 18.46 ± 4.18 % (n=10) ([(18)F]fluorophenylglutamine) and 8.05 ± 3.25 % (n=5) ([(18)F]fluorobiphenylglutamine). In vitro inhibition experiments showed a moderate and low affinity of fluorophenylglutamine and fluorobiphenylglutamine, respectively, towards the human ASCT-2 transporter. Both compounds had a low affinity towards the rat ASCT-2 transporter. These results were endorsed by the in vivo experiments with low uptake of both tracers in the F98 rat xenograft, low uptake of [(18)F]FBPG in the mice PC-3 xenograft and a moderate uptake of [(18)F]FPG in the PC-3 tumors. CONCLUSION: We investigated the imaging potential of two novel PET radiotracers [(18)F]FPG and [(18)F]FBPG. [(18)F]FPG is the first example of a glutamine radiotracer derivatized with a phenyl group which enables the exploration of further derivatization of the phenyl group to increase the affinity and imaging qualities. We hypothesize that increasing the affinity of [(18)F]FPG by optimizing the substituents of the arene ring can result in a high-quality glutamine-based PET radiotracer. ADVANCES IN KNOWLEDGE AND IMPLICATIONS FOR PATIENT CARE: We hereby report novel glutamine-based PET-tracers. These tracers are tagged on the arene group with fluorine-18, hereby preventing in vivo defluorination, which can occur with alkyl labelled tracers (e.g. (2S,4R)4-[(18)F]fluoroglutamine). [(18)F]FPG shows clear tumor uptake in vivo, has no in vivo defluorination and has a straightforward production. We believe this tracer is a good starting point for the development of a high-quality tracer which is useful for the clinical visualization of the glutamine transport

    Synthesis, in vitro, and in vivo biological evaluation and molecular docking simulations of chiral alcohol and ether derivatives of the 1,5-diarylpyrrole scaffold as novel anti-inflammatory and analgesic agents.

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    Following our previous research on anti-inflammatory drugs (NSAIDs), we report here the synthesis of chiral 1,5-diarylpyrroles derivatives that were characterized for their in vitro inhibitory effects toward cyclooxygenase (COX) isozymes. Analysis of enzymatic affinity and COX-2 selectivity led us to the selection of one compound (+/-)-10b that was further tested in vitro in the human whole blood (HWB) and in vivo for its anti-inflammatory activity in mice. The affinity data have been rationalized through docking simulations

    From fix to fit into the autoptic human brains.

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    Formalin-fixed, paraffinembedded (FFPE) human brain tissues are very often stored in formalin for long time. Formalin fixation reduces immunostaining, and the DNA/RNA extraction from FFPE brain tissue becomes suboptimal. At present, there are different protocols of fixation and several procedures and kits to extract DNA/RNA from paraffin embedding tissue, but a gold standard protocol remains distant. In this study, we analyzed four types of fixation systems and compared histo and immuno-staining. Based on our results, we propose a modified method of combined fixation in formalin and formic acid for the autoptic adult brain to obtain easy, fast, safe and efficient immunolabelling of long-stored FFPE tissue. In particular, we have achieved an improved preservation of cellular morphology and obtained success in postmortem immunostaining for NeuN. This nuclear antigen is an important marker for mapping neurons, for example, to evaluate the histopathology of temporal lobe epilepsy or to draw the topography of cardiorespiratory brainstem nuclei in sudden infant death syndrome (SIDS). However, NeuN staining is frequently faint or lost in postmortem human brain tissues. In addition, we attained Fluoro Jade C staining, a marker of neurodegeneration, and immunofluorescent staining for stem cell antigens in the postnatal human brain, utilizing custom fit fixation procedures

    Enhanced dispersibility of graphitic carbon nitride particles in aqueous and organic media via a one-pot grafting approach

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    A facile route to synthesize hydrophilically or hydrophobically grafted graphitic carbon nitride (g-CN) is reported. For this purpose, functionalized olefinic molecules with a low polymerization tendency are utilized for grafting onto the surface to preserve the features of g-CN while improving its dispersibility. One-pot, visible light-induced grafting yields highly dispersible g-CNs either in aqueous or organic media. Moreover, functional groups such as amines can be introduced, which yields pH-dependent dispersibility in aqueous media. Compared with unfunctionalized g-CN, low sonication times are sufficient to redisperse g-CN. In addition, because of increased dispersion stability, higher amounts of functionalized g-CN can be dispersed (up to 10% in aqueous dispersion and 2% in organic dispersion) when compared to unfunctionalized g-CN

    ROR-γ drives androgen receptor expression and represents a therapeutic target in castration-resistant prostate cancer.

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    The androgen receptor (AR) is overexpressed and hyperactivated in human castration-resistant prostate cancer (CRPC). However, the determinants of AR overexpression in CRPC are poorly defined. Here we show that retinoic acid receptor-related orphan receptor γ (ROR-γ) is overexpressed and amplified in metastatic CRPC tumors, and that ROR-γ drives AR expression in the tumors. ROR-γ recruits nuclear receptor coactivator 1 and 3 (NCOA1 and NCOA3, also known as SRC-1 and SRC-3) to an AR-ROR response element (RORE) to stimulate AR gene transcription. ROR-γ antagonists suppress the expression of both AR and its variant AR-V7 in prostate cancer (PCa) cell lines and tumors. ROR-γ antagonists also markedly diminish genome-wide AR binding, H3K27ac abundance and expression of the AR target gene network. Finally, ROR-γ antagonists suppressed tumor growth in multiple AR-expressing, but not AR-negative, xenograft PCa models, and they effectively sensitized CRPC tumors to enzalutamide, without overt toxicity, in mice. Taken together, these results establish ROR-γ as a key player in CRPC by acting upstream of AR and as a potential therapeutic target for advanced PCa

    6-Deoxyhexoses froml-Rhamnose in the Search for Inducers of the Rhamnose Operon: Synergy of Chemistry and Biotechnology

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    In the search for alternative non‐metabolizable inducers in the l ‐rhamnose promoter system, the synthesis of fifteen 6‐deoxyhexoses from l ‐rhamnose demonstrates the value of synergy between biotechnology and chemistry. The readily available 2,3‐acetonide of rhamnonolactone allows inversion of configuration at C4 and/or C5 of rhamnose to give 6‐deoxy‐d ‐allose, 6‐deoxy‐d ‐gulose and 6‐deoxy‐l ‐talose. Highly crystalline 3,5‐benzylidene rhamnonolactone gives easy access to l ‐quinovose (6‐deoxy‐l ‐glucose), l ‐olivose and rhamnose analogue with C2 azido, amino and acetamido substituents. Electrophilic fluorination of rhamnal gives a mixture of 2‐deoxy‐2‐fluoro‐l ‐rhamnose and 2‐deoxy‐2‐fluoro‐l ‐quinovose. Biotechnology provides access to 6‐deoxy‐l ‐altrose and 1‐deoxy‐l ‐fructose

    Cyclooxygenase-2 inhibitors. 1,5-diarylpyrrol-3-acetic esters with enhanced inhibitory activity toward cyclooxygenase-2 and improved cyclooxygenase-2/cyclooxygenase-1 selectivity.

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    he important role of cyclooxygenase-2 (COX-2) in the pathogenesis of inflammation and side effect limitations of current COX-2 inhibitor drugs illustrates a need for the design of new compounds based on alternative structural templates. We previously reported a set of substituted 1,5-diarylpyrrole derivatives, along with their inhibitory activity toward COX enzymes. Several compounds proved to be highly selective COX-2 inhibitors and their affinity data were rationalized through docking simulations. In this paper, we describe the synthesis of new 1,5-diarylpyrrole derivatives that were assayed for their in vitro inhibitory effects toward COX isozymes. Among them, the ethyl-2-methyl-5-[4-(methylsulfonyl)phenyl]-1-[3-fluorophenyl]-1H-pyrrol-3- acetate (1d), which was the most potent and COX-2 selective compound, also showed a very interesting in vivo anti-inflammatory and analgesic activity, laying the foundations for developing new lead compounds that could be effective agents in the armamentarium for the management of inflammation and pain
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