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31.
Thorsten Will Michael C. Hutter Johann Jauch Volkhard Helms 《Journal of computational chemistry》2013,34(28):2485-2492
Besides all their conformational degrees of freedom, drug‐like molecules and natural products often also undergo tautomeric interconversions. Compared to the huge efforts made in experimental investigation of tautomerism, open and free algorithmic solutions for prototropic tautomer generation are surprisingly rare. The few freely available software packages limit their output to a subset of the possible configurational space by sometimes unwanted prior assumptions and complete neglection of ring‐chain tautomerism. Here, we describe an adjustable fully automatic tautomer enumeration approach, which is freely available and also incorporates the detection of ring‐chain variants. The algorithm is implemented in the MolTPC framework and accessible on SourceForge. © 2013 Wiley Periodicals, Inc. 相似文献
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Development of an automated dual‐mode supercritical fluid chromatography and reversed‐phase liquid chromatography mass‐directed purification system for small‐molecule drug discovery 下载免费PDF全文
Kanaka Hettiarachchi May Kong Andersen Yun John R. Jacobsen Qifeng Xue 《Journal of separation science》2014,37(7):775-781
We report the development of a dual‐mode mass‐directed supercritical fluid chromatography and reversed‐phase liquid chromatography purification system. The addition of a third pump allows for flexible mobile phase control between the two techniques, and enables operation of either chromatography mode within minutes by activation of a set of switching valves on a single system. Software control, fluidic pathways, interface to the mass spectrometer, and fraction collection have been modified for compatibility between both separation methods. The conditioning solvent and tuning parameters for the mass spectrometer were adjusted to achieve an ideal signal trace in either mode with good linearity (r2 > 0.970) over a range of concentrations and minimal noise for accurate peak detection and isolation. The registration success rate is 90% and overall sample recovery for either technique is 80?90%. Combining two orthogonal separation and purification modes in one single system has improved the purification throughput of complex mixtures and has been a valuable, cost‐saving tool in our laboratory. 相似文献
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Szentmihályi Klára May Zoltán Bódis Eszter Tóth Judit Trif László Klébert Szilvia Feczkó Tivadar Károly Zoltán 《Journal of Thermal Analysis and Calorimetry》2022,147(21):11777-11786
Journal of Thermal Analysis and Calorimetry - Spray freeze-drying (SFD) is an effective method for reducing the size of thermosensitive organic substances that are sparingly soluble in water.... 相似文献
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Jens Moons Dr. Francisco de Azambuja Jelena Mihailovic Karoly Kozma Dr. Katarina Smiljanic Mehran Amiri Prof. Tanja Cirkovic Velickovic Prof. May Nyman Prof. Tatjana N. Parac-Vogt 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(23):9179-9186
The selective hydrolysis of proteins by non-enzymatic catalysis is difficult to achieve, yet it is crucial for applications in biotechnology and proteomics. Herein, we report that discrete hafnium metal-oxo cluster [Hf18O10(OH)26(SO4)13⋅(H2O)33] ( Hf18 ), which is centred by the same hexamer motif found in many MOFs, acts as a heterogeneous catalyst for the efficient hydrolysis of horse heart myoglobin (HHM) in low buffer concentrations. Among 154 amino acids present in the sequence of HHM, strictly selective cleavage at only 6 solvent accessible aspartate residues was observed. Mechanistic experiments suggest that the hydrolytic activity is likely derived from the actuation of HfIV Lewis acidic sites and the Brønsted acidic surface of Hf18 . X-ray scattering and ESI-MS revealed that Hf18 is completely insoluble in these conditions, confirming the HHM hydrolysis is caused by a heterogeneous reaction of the solid Hf18 cluster, and not from smaller, soluble Hf species that could leach into solution. 相似文献
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A 3-D surface profilometer is described which uses a simple fiber optic coupler to form a Young's double pinhole interferometer. The Young's fringes are projected onto a surface, captured by a camera and analyzed using the Fourier transform method. The phase of the fringe pattern on the object is used to reconstruct the surface profile. System analysis, results from a simulation, and preliminary experimental results are provided which indicate a system resolution on the order of a tenth of a millimeter. 相似文献
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Patricia Dähmlow Torsten Trittel Kathrin May Kirsten Harth Ralf Stannarius 《Liquid crystals》2018,45(7):993-1003
Elongated freely floating smectic bubbles are observed during their relaxation to equilibrium sphere shape. Unlike soap bubbles that perform weakly damped oscillations into equilibrium, this relaxation is overdamped in smectics by internal structure reorganisation processes. The bubble area reduction of centimetre-sized freely floating bubbles with few nanometres film thickness is recorded with high-speed optical imaging in microgravity and analysed quantitatively. We find a nearly linear reduction of the film area with time, driven by capillary forces and inhibited by smectic layer reorganisations. Characteristic times are in the milliseconds range, with little correlation to the film thickness and bubble size. Instead, the homogeneity of the films and the number and sizes of islands of excess layers that spontaneously form on the films appear to have crucial influence on the dynamics. The efficiency of this process sets the time scale of the film area shrinkage. We discuss the limitations of a minimalistic model that captures smectic layer reorganisation processes. 相似文献
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