259 research outputs found

    Aryl Sulfonates in Inversions at Secondary Carbohydrate Hydroxyl Groups: A New and Improved Route Toward 3-Azido-3-deoxy-beta-D-galactopyranosides

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    A method of using benzenesulfonates and imidazylates as leaving groups at the secondary C3 galactopyranose carbon, instead of the commonly used less stable triflate leaving group, to facilitate scale-up and improve reproducibility is disclosed. The benzenesulfonates and imidazylates were proven to be significantly more stable than the corresponding triflates and the method was used to devise an improved route toward 3-azido-3-deoxy-beta-D-galactopyranosides

    Investigating the influence of (Deoxy)fluorination on the lipophilicity of non-UV-active fluorinated alkanols and carbohydrates by a new log P determination method

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    Property tuning by fluorination is very effective for a number of purposes, and currently increasingly investigated for aliphatic compounds. An important application is lipophilicity (log?P) modulation. However, the determination of log?P is cumbersome for non-UV-active compounds. A new variation of the shake-flask log?P determination method is presented, enabling the measurement of log?P for fluorinated compounds with or without UV activity regardless of whether they are hydrophilic or lipophilic. No calibration curves or measurements of compound masses/aliquot volumes are required. With this method, the influence of fluorination on the lipophilicity of fluorinated aliphatic alcohols was determined, and the log?P values of fluorinated carbohydrates were measured. Interesting trends and changes, for example, for the dependence on relative stereochemistry, are reporte

    6-De­oxy-6-fluoro-d-galactose

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    The crystal structure unequivocally confirms the relative stereochemistry of the title compound, C6H11FO5. The absolute stereochemistry was determined by the use of d-galactose as the starting material. The compound exists as a three-dimensional O—H⋯O hydrogen-bonded network with each mol­ecule acting as a donor and acceptor for four hydrogen bonds

    Functional Analysis of MycE and MycF, Two O -Methyltransferases Involved in the Biosynthesis of Mycinamicin Macrolide Antibiotics

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    Mg motors : We characterized the in vitro function of MycE and MycF, two O -methyltransferases involved in the biosynthesis of mycinamicin antibiotics. Each enzyme was confirmed to be an S -adenosyl- L -methionine (SAM)-dependent deoxysugar methyltransferase. Their optimal activities require the presence of Mg 2+ . With the reconstituted in vitro assays, the order of mycinamicin VI→III→IV in the post-PKS (polyketide synthase) tailoring pathway of mycinamicin was unambiguously determined.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62994/1/1297_ftp.pd

    Pauli's Principle in Probe Microscopy

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    Exceptionally clear images of intramolecular structure can be attained in dynamic force microscopy through the combination of a passivated tip apex and operation in what has become known as the "Pauli exclusion regime" of the tip-sample interaction. We discuss, from an experimentalist's perspective, a number of aspects of the exclusion principle which underpin this ability to achieve submolecular resolution. Our particular focus is on the origins, history, and interpretation of Pauli's principle in the context of interatomic and intermolecular interactions.Comment: This is a chapter from "Imaging and Manipulation of Adsorbates using Dynamic Force Microscopy", a book which is part of the "Advances in Atom and Single Molecule Machines" series published by Springer [http://www.springer.com/series/10425]. To be published late 201

    Feasibility and acceptability of integrated psychological therapy versus treatment as usual for people with bipolar disorder and co-morbid alcohol use:A single blind randomised controlled trial

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    Background Alcohol use is a common problem in bipolar disorder (BD) and evidence indicates more promising outcomes for alcohol use than other substances. No trials have evaluated individual integrated motivational interviewing and cognitive behaviour therapy (MI-CBT) for problematic alcohol use in BD. We therefore assessed the feasibility and acceptability of a novel MI-CBT intervention for alcohol use in BD. Methods A single blind RCT was conducted to compare MI-CBT plus treatment as usual (TAU) with TAU only. MI-CBT was delivered over 20 sessions with participants followed up at 3, 6, 9 and 12 months post-randomisation. Primary outcomes were the feasibility and acceptability of MI-CBT (recruitment to target, retention to follow-up and therapy, acceptability of therapy and absence of adverse events). We also conducted preliminary analyses of alcohol and mood outcomes (frequency and severity of alcohol use and time to mood relapse). Results 44 participants were recruited with 75% retention to 6 and 12 months follow-up. Therapy participants attended a mean of 17.6 (SD 4.5) sessions. Therapy alliance and treatment fidelity were acceptable. Qualitative interviews indicated the intervention was experienced as collaborative, and helpful, in addressing mood and alcohol issues, although risk of overconfidence following therapy was also identified. Clinical outcomes did not differ between arms at 12 months follow-up. Limitations As a feasibility and acceptability trial any secondary results should be treated with caution. Conclusions Integrated MI-CBT is feasible and acceptable, but lack of clinical impact, albeit in a feasibility study, suggests need for further development. Potential adaptations are discussed

    3α,7-dihydroxy-14(13→12)abeo-5β,12α(H),13β(H)-cholan-24-oic acids display neuroprotective properties in common forms of Parkinson’s disease

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    Parkinson’s Disease is the most common neurodegenerative movement disorder globally, with prevalence increasing. There is an urgent need for new therapeutics which are disease-modifying rather than symptomatic. Mitochondrial dysfunction is a well-documented mechanism in both sporadic and familial Parkinson’s Disease. Furthermore, ursodeoxycholic acid (UDCA) has been identified as a bile acid which leads to increased mitochondrial function in multiple in vitro and in vivo models of Parkinson’s Disease. Here, we describe the synthesis of novel C-nor-D-homo bile acid derivatives and the 12-hydroxy-methylated derivative of lagocholic acid (7) and their biological evaluation in fibroblasts from patients with either sporadic or LRRK2 mutant Parkinson’s Disease. These compounds boost mitochondrial function to a similar level or above that of UDCA in many assays; notable, however, is their ability to boost mitochondrial function to a higher level and at lower concentrations than UDCA specifically in the fibroblasts from LRRK2 patients. Our study indicates that novel bile acid chemistry could lead to the development of more efficacious bile acids which increase mitochondrial function and ultimately cellular health at lower concentrations proving attractive potential novel therapeutics for Parkinson’s Disease
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