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关键词： In vitro ADME profile   Physicochemical properties   P-gp   BCRP   Microsomal stability   hERG inhibition   Plasma protein binding  

摘要： We analyzed the influence of calculated physicochemical properties of more than 20,000 compounds on their Pgp and BCRP mediated efflux, microsomal stability, hERG inhibition, and plasma protein binding. Our goal was to provide guidance for designing compounds with desired pharmacokinetic profiles. Our analysis showed that compounds with ClogP less than 3 and molecular weight less than 400 will have high microsomal stability and low plasma protein binding. Compounds with logD less than 2.2 and/or basic pKa larger than 5.3 are likely to be BCRP substrates and compounds with basic pKa less than 5.2 and/or acidic pKa less than 13.4 are less likely to inhibit hERG. Based on these results, compounds with MW < 400, ClogP < 3, basic pKa < 5.2 and acidic pKa < 13.4 are likely to have good bioavailability and low hERG inhibition.

关键词： Diosgenin   Sapogenin   Cholesterol   Deuterium NMR   DPH   Laurdan   Prodan  

摘要： Diosgenin (DGN), which is a sterol occurring in plants of the Dioscorea family, has attracted increasing attention for its various pharmacological activities. DGN has a structural similarity to cholesterol (Cho). In this study we investigated the effects of the common tetracyclic cores and the different side chains on the physicochemical properties of lipid bilayer membranes. Differential scanning calorimetry showed that DGN and Cho reduce the phase transition enthalpy to a similar extent. In H-2 NMR, deuterated-DGN/Cho and POPC showed similar ordering in POPC bilayers, which revealed that DGN is oriented parallel to the membrane normal like Cho. It was suggested that the affinity of DGN-Cho in membrane is stronger than that of DGN-DGN or Cho-Cho interaction. P-31 NMR of POPC in bilayers revealed that, unlike Cho, DGN altered the interactions of POPC headgroups at 30 mol%. These results suggest that DGN below 30 mol% has similar effects with Cho on basic biomembrane properties.

关键词： Lanthanide oxide   Functionalization   Physicochemistry   Superhydrophobicity   Petal and lotus effect  

摘要： According to the developed bioinspired method in the one-step procedure, the material with the petal effect was switched to lotus one. Therefore, highly hydrophobic and super-hydrophobic materials with tunable adhesive properties and fractal-like structures were successfully produced with high efficiency (67-84%). The work's essence was to modify chemically selected powders of lanthanide oxides (CeO2, Pr6O11, Nd2O3, and Gd2O3). High effectiveness of the functionalization process with 1H,1H,2H,2H-perfluorooctyltriethoxysilane (FC6) and n-octyltriethoxysilane (C6) was proven by various techniques, e.g. XPS, HR-TEM, ATR, XRD, zeta potential. Materials with water contact angle between 143.6 degrees (CeO2-C6) and 175.5 degrees (Nd2O3-FC6) with thermally stable nanolayer (up to 380 degrees C) were generated. Surfaces functionalized with FC6 possessed a polar component of surface free energy (SFE) close to zero. Water behavior in contact with the modified materials was studied, taking into consideration the unique electron structure of lanthanides assessed by goniometric measurement, also adhesion and spreading pressure were determined. Very low adhesion and polar SFE partly resulted in immediate bouncing of water droplet upon contact with the modified surface. The presented method allows preparing stable materials with a high potential in materials chemistry and modulation of surface features and engineering (e.g. heat transfer fluids, specific coating).

关键词： Density functional theory  

摘要： Synthon preference is perceived in the pyridyl salts of multi-functional organo-sulfonates and validated through density functional theory (DFT) studies. The salt 1 of 5-sulfosalicylic acid (5-SSA-3H) as well as previously reported pyridyl salts of 5-SSA-3H indicates preferential formation of sulfonate-pyridinium interaction I over common and robust carboxylic-pyridine/carboxylate-pyridinium II as well as hydroxyl-pyridine/hydroxylate-pyridinium III interactions. Pyridyl salts of further functional organo-sulfonates 8-hydroxyquinoline sulfonic acid (8-HQSA-2H) 2 and Schiff bases of sulfanilic acid and syringaldehyde (4-ABSA-SA-2H) 3 show preference for bifurcated hydroxyl assisted pyridinium-pyridine IV and methoxy assisted pyridinium-hydroxylate V synthons. The observed synthon preference is also supported by previously reported organic salts. The overall synthon preference IV similar to V > I >> II >> III is further validated through DFT studies, whereas QTAIM studies substantiate the electrostatic nature of interactions I-V with some covalent character. Hirshfeld studies of the organic salts indicate that reciprocal O-HMIDLINE HORIZONTAL ELLIPSISH-O and HMIDLINE HORIZONTAL ELLIPSISH interactions are the major interactions responsible for packing, whereas 3 exhibits higher CMIDLINE HORIZONTAL ELLIPSISC interactions than 1 and 2, which is substantiated by significant pi-stacking in 3 and its absence in 1 and 2. Furthermore, the organic salts exhibit augmented thermal and chemical stability, plausibly due to the ionic nature of the crystal lattice. The optical behaviour of the salts corroborates with crystallographic packing and red shift in the absorption of 3 is attributed to pi-pi interactions between crystal formers. Organic salts 2 and 3 exhibit augmented aqueous solubility compared to pristine precursors, and enhancement in the solubility of 3 is striking with a value of 1175% compared to the organo-sulfonate precursor.

关键词： Metal nanoparticles   Metals   Gold   Metal clusters   Chemical synthesis  

关键词： Antibiotic   Membrane separation   Photocatalysis   Halloysite   Activated charcoal  

摘要： Membrane separation technology has been widely utilised to obtain clean permeate and concentrated nutrients from biogas digested slurry. However, some antibiotics are frequently found in digested slurry. Antibiotic removal during the steps, including paper filtration (PF), hollow-fibremembrane ultrafiltration (HF), nanofiltration (NF) and reverse osmosis (RO), of combined membrane separation processing (CMP) remain poorly understood. Experimentswere performed on a pilot-scale CMP plant to investigate antibiotic transport and rejection efficiencies in CMP products and analyse the antibiotic removal performances of additional treatments. Results showed average relative antibiotic rejection efficiencies of 50%, 83%, 28% and 14% for PF, HF, NF and RO during CMP, respectively. Each CMP product needed additional treatment for antibiotic removal. Antibiotic removal capacity followed the order of fine halloysite > P25 > activated charcoal > coarse halloysite. The average antibiotic removal rates for different CMP products ranged from 73.3% to 99.9%. But antibiotics can only be adsorbed by fine halloysite andmust be degraded through other treatments, Thus, P25 has considerable practical importance for the removal of antibiotics, as antibiotics can be degraded during photocatalysis. (C) 2020 Elsevier B.V. All rights reserved.

关键词： Upper-Division Undergraduate   Physical Chemistry   Hands-On Learning/Manipulatives   Spectroscopy  

摘要： Few laboratory exercises exist that introduce undergraduate students to both the concepts and instrumentation used in rotational spectroscopy. Because of this gap in undergraduate laboratory training, a teaching laboratory for the pure rotational spectroscopy of benzonitrile has been developed and reported. Owing to benzonitrile's recent discovery in space, the molecular spectroscopic technique and target are applicable to both the physical chemistry and astronomy disciplines. Because of the size of the dipole moment and relative safety of the molecule chosen, the laboratory approach allows undergraduates to directly load, tune, measure, and assign spectra using the same quantum chemical approaches and spectroscopic assigning tools available to a researcher in the field. Concepts taught in this laboratory include the rigid and semirigid rotor, as well as low-level nuclear electric quadrupole coupling Hamiltonians. To minimize the budget and allow the students to get hands-on training with the rotational spectroscopy instrumentation, an interactive, low-cost, Balle-Flygare-type, cavity Fourier transform microwave (FTMW) spectrometer of research-grade quality was developed and is reported. Implementation of the laboratory exercise, time of exercise, and student response to the exercise is also reported.

关键词： Respirable dust   Coal mine   Oxidative potential   Toxic elements  

摘要： This study investigates the mineralogy, micro-morphology, chemical characteristics and oxidation toxicity of respirable dusts generated in underground coal mines. The active sampling was applied to collect airborne particulates with aerodynamic diameter <4 mu m (PM4) at depth greater than 500 m from earth surface. The average mass concentration of PM4 was extremely higher than recommended values. QXRD and FESEM-EDS analyses were applied to study the micro-mineralogy and micro-morphology of respirable dusts. The chemical analysis by ICP-MS revealed an enrichment of V, Cr, Cu, Zn, As, Ag, Cd and Sb in respirable dust compared with the background environment and world coals. The EPA's health risk model showed that the health risk posed by Cr and Co in all workplaces exceeded the acceptable risk value for human health. The synthetic respiratory tract lining fluid (RTLF) model was utilized to achieve a novel insight into the toxicity of respirable coal dust. The result showed an overall depletion of lung surface antioxidants with the decreasing trend of ascorbic acid > reduced glutathione >> urate, implying low- to medium level of oxidative stress. The result of this study can be applied globally by decision-makers to decrease hazardous exposure of mine workers to respirable dust.

关键词： Dispiroheterocycle   XRD analysis   DFT studies   NBO & NLO analysis   Hirshfeld surface analysis  

摘要： We present Et3N mediated synthesis of a novel dispirocompound from 5-methyl-2-(4'-fluorophenylidine)-1-oxo-1,2,3,8-tetrahydrocyclopent[b]indole, isatin, and sarcosine through 1,3-dipolar cycloaddition reaction. The crystal structure of synthesised compound, 4'-(4-fluorophenyl)-2',7-dimethyl-1,4-dihydro-3H-dispiro[cyclopent[b]indol-2,5'-[1,2]oxazinan-6',3 ''-indolinl-2 '',3-dione is reported. FT-IR, H-1 and C-13 NMR chemical shifts as measured and calculated using B3LYP method with the 6-311G(d,p) basis set in gas phase were found in good agreement. The optimized geometry of the dispirocompound was compared with experimental XRD values. DFT calculations of the molecular electrostatic potential (MEP), Non-covalent interactions and Hirshfeld Surface analysis, Non-linear optical (NLO) properties and frontier molecular orbitals (FMO) identified chemically active sites of the dispirocompound responsible for its chemical reactivity. (C) 2020 Elsevier B.V. All rights reserved.

关键词： Bismuth material   X-ray diffraction   Thermal analysis   Hirshfeld surfaces   Vibrational studies   Photoluminescence absorption  

摘要： In the present work, the new organic-inorganic hybrid material (C5H8N3)(C5H9N3)BiCl6 was elaborated by halobismuthates as building units and 3,4-diaminopyridinium organic cations. The title compound is crystalized at room temperature by slow evaporation in the monoclinic space group P2(1)/n with the following parameters a = 7.197 (2)angstrom, b = 23.106 (9)angstrom, c = 11.780 (5)angstrom, beta-96.443 (3)degrees Z = 4 and V = 1946.5 (12)angstrom(3). The structure is built up of separated BiCl63- octahedral chlorine coordination and two molecules of 3,4-diaminopyridinium with two different protonation sites aminopyridine (one is mono-protonated and the other is di-protonated), which are linked via N-H center dot center dot center dot Cl hydrogen bonds forming a zero dimensional network. The atomic arrangement can be described as an alternation of organic and inorganic layers. Besides, the nature of the distortion of the inorganic polyhedral has been studied and can be attributed to the stereo activity of the Bi(III) lone electron pair. The infrared IR and Raman studies were recorded in the 4000-400 cm(-1) frequency region and the Raman spectra was recorded in the external region of the anionic sublattice vibration 500 -50 cm(-1). The thermal decomposition of precursors studied by differential scanning calorimetry (DSC), confirms the degradation of the title compound around 135 and 137 degrees C. The photoluminescence spectrum exhibits two strong bands of luminescence located at 377 and 580 nm which are attributed to the band-to-band and exciton emissions within the chlorobismuthate inorganic part, respectively. (C) 2020 Elsevier B.V. All rights reserved.