8 research outputs found

    Synthesis, Chiral Resolution, and Absolute Configuration of Dissymmetric 4,15-Difunctionalized [2.2]Paracyclophanes

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    Despite the fact that functionalized planar chiral [2.2]­paracyclophanes have received a lot of attention, the chemistry of pseudo-<i>meta</i> 4,15-distubstituted [2.2]­paracyclophanes is largely unexplored. This is mainly due to the fact that the 4,5-dibromo-functionalized [2.2]­paracyclophane is much less prone to halogen-metal exchange reactions than its constitutional pseudo-<i>ortho</i> or pseudo-<i>para</i> isomers. Here, we give an account of an efficient protocol to achieve this, which allows the synthesis of a broad variety of 4,15-disubstituted [2.2]­paracyclophanes. Furthermore, we were able to resolve several of the racemic compounds via chiral HPLC and assign the absolute configurations of the isolated enantiomers by X-ray diffraction and/or by the comparison of calculated and measured CD-spectra

    Synthesis, Chiral Resolution, and Absolute Configuration of Dissymmetric 4,15-Difunctionalized [2.2]Paracyclophanes

    No full text
    Despite the fact that functionalized planar chiral [2.2]­paracyclophanes have received a lot of attention, the chemistry of pseudo-<i>meta</i> 4,15-distubstituted [2.2]­paracyclophanes is largely unexplored. This is mainly due to the fact that the 4,5-dibromo-functionalized [2.2]­paracyclophane is much less prone to halogen-metal exchange reactions than its constitutional pseudo-<i>ortho</i> or pseudo-<i>para</i> isomers. Here, we give an account of an efficient protocol to achieve this, which allows the synthesis of a broad variety of 4,15-disubstituted [2.2]­paracyclophanes. Furthermore, we were able to resolve several of the racemic compounds via chiral HPLC and assign the absolute configurations of the isolated enantiomers by X-ray diffraction and/or by the comparison of calculated and measured CD-spectra

    Effect of High-Flux Dialysis on Circulating FGF-23 Levels in End-Stage Renal Disease Patients: Results from a Randomized Trial

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    <div><p>Background</p><p>In patients undergoing maintenance hemodialysis (HD), increased levels of circulating fibroblast growth factor-23 (FGF-23) are independently associated with cardiovascular events and mortality. Interventional strategies aiming to reduce levels of FGF-23 in HD patients are of particular interest. The purpose of the current study was to compare the impact of high-flux versus low-flux HD on circulating FGF-23 levels.</p><p>Methods</p><p>We conducted a post-hoc analysis of the MINOXIS study, including 127 dialysis patients randomized to low-flux (n = 62) and high-flux (n = 65) HD for 52 weeks. Patients with valid measures for FGF-23 investigated baseline and after 52 weeks were included.</p><p>Results</p><p>Compared to baseline, a significant increase in FGF-23 levels after one year of low-flux HD was observed (Delta plasma FGF-23: +4026 RU/ml; p < 0.001). In contrast, FGF-23 levels remained stable in the high flux group (Delta plasma FGF-23: +373 RU/ml, p = 0.70). The adjusted difference of the absolute change in FGF-23 levels between the two treatment groups was statistically significant (p < 0.01).</p><p>Conclusions</p><p>Over a period of 12 months, high-flux HD was associated with stable FGF-23 levels, whereas the low-flux HD group showed an increase of FGF-23. However, the implications of the different FGF 23 time-trends in patients on high flux dialysis, as compared to the control group, remain to be explored in specifically designed clinical trials.</p><p>Trial Registration</p><p>German Clinical Trials Register (DRKS) <a href="https://drks-neu.uniklinik-freiburg.de/drks_web/navigate.do?navigationId=trial.HTML#x0026;TRIAL_ID=DRKS00007612" target="_blank">DRKS00007612</a>.</p></div

    Baseline characteristics of the study population.

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    <p>Values presented with numbers in parentheses are mean (SD). CHD, coronary heart disease; MI, myocardial infarction; CHF, congestive heart failure; hs-CRP, high-sensitivity C-reactive protein; UF, ultrafiltration; HMG-CoA, hydroxymethyl glutaryl coenzyme A; ASS, acetylsalicylic acid.</p><p><sup>a</sup> Median (interquartile range).</p><p>Baseline characteristics of the study population.</p
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