No / The structure of 5-N-hydroxyethanequindoline hydrochloride methanolate, C17H15ON2 Cl·½CH3OH, M r = 314.78, has been determined from X-ray diffraction data. The crystals are monoclinic, space group C2/c, with Z = 8 molecules per unit cell and a = 18.179(11), b = 7.317(5), c = 24.125(15) Å, β = 110.155(10)°, V c = 3012(3) Å3, crystal density D c = 1.388 Mg m−3. The structure was solved by direct methods, and the asymmetric unit comprises the 5-N-hydroxyethanequindoline hydrochloride and ½CH3OH moiety. The methanol is unusually disordered over a twofold axis with the C atom slightly removed from the twofold axis. Restraints were applied to the bond lengths of the two components of the disordered CH3OH, and to the anisotropic thermal displacement parameters of the disordered CH3OH carbon atom. The heterocyclic quindoline ring system and the first C atom of the hydroxyethane side chain are planar within 0.02 Å, with the terminal C–OH atoms of the side chain significantly out of the plane. The crystal structure is maintained via three hydrogen bonds all involving the chlorine atom an oxygen in the hydroxyethane side chain, a nitrogen in the quindoline moiety and the methanol oxygen.

No / This article reports the structural elucidation of the Alangium alkaloid, tubulosine (1) on the basis of systematic 2D-NMR analyses (DEPT, COSY, TOCSY, NOESY, ROESY, HMQC and HMBC). The data obtained allowed the unambiguous assignment of all proton and carbon signals in 1 for the first time.

Yes / The first 1H, 13C, 31P and 11B solid state MAS NMR studies of electron- deficient carborane-containing ruthenium and osmium complexes [Ru/Os(p-cym)(1,2-dicarba-closo-dodecaborane-1,2- dithiolate)] are reported. The MAS NMR data from these 16-electron complexes are compared to those of free carborane-ligand and an 18-electron triphenylphosphine ruthenium adduct, and reveal clear spectral differences between 16- and 18-electron organometallic carborane systems in the solid state. / We thank the Swiss National Science Foundation (grant no. PA00P2-145308 to NPEB), the ERC (grant no. 247450 to PJS), EPSRC (grant no. EP/F034210/1) and EC COST Action CM1105 for support. JVH thanks EPSRC and the University of Warwick for partial funding of the solid state NMR infrastructure at Warwick, and acknowledges additional support obtained through Birmingham Science City: Innovative Uses for Advanced Materials in the Modern World (West Midlands Centre for Advanced Materials Project 2), with support from Advantage West Midlands (AWM) and partial funding by the European Regional Development Fund (ERDF).

Yes / When the 'CO-releasing molecule-3', CORM-3 (Ru(CO)3Cl(glycinate)), is dissolved in water it forms a range of ruthenium complexes. These are taken up by cells and bind to intracellular ligands, notably thiols such as cysteine and glutathione, where the Ru(II) reaches high intracellular concentrations. Here, we show that the Ru(II) ion also binds to DNA, at exposed guanosine N7 positions. It therefore has a similar cellular target to the anticancer drug cisplatin, but not identical, because Ru(II) shows no evidence of forming intramolecular crossbridges in the DNA. The reaction is slow, and with excess Ru, intermolecular DNA crossbridges are formed. The addition of CORM-3 to human colorectal cancer cells leads to strand breaks in the DNA, as assessed by the alkaline comet assay. DNA damage is inhibited by growth media containing amino acids, which bind to extracellular Ru and prevent its entry into cells. We conclude that the cytotoxicity of Ru(II) is different from that of platinum, making it a promising development target for cancer therapeutics.

The diffusion behavior of guest molecules introduced in porous materials has been studied. Diffusion studies in such porous materials may help for elucidating the structural properties, transport mechanism and/or surface barriers of the zeolite structure. The focus of this work is on diffusion in nanoporous materials with complex pore spaces. First a short introduction in the basics of diffusion and the PFG NMR technique (Pulsed Field Gradient Nuclear Magnetic Resonance) is described. In the following two chapters the diffusion in hierarchical pore spaces or, to be more precise, zeolites with generated mesopores, which traverse the microporous bulk phase, are investigated. The hierarchical pore spaces consists in the first case of micro- and mesopores and in the second case of micro-, meso- and macropores. The diffusion behavior in these materials has been investigated revealing diffusion acceleration in the mesoporous samples, as compared to the purely microporous material. In the next chapter the diffusion behavior in glass samples with different porosity and their complementary pore space is investigated. Diffusion with full loaded pore spaces and surface diffusion, where the molecules were only able to diffuse along the pore walls, has been explored. The aim was to find out to what extent the diffusion in two complementary pore spaces is correlated. In the last chapter, the effect of an inorganic binder on the transport in zeolite pellets has been studied. First the diffusion behavior in binderless zeolite beads in comparison with the zeolite powder employed for their production has been explored. The particular interest was to find out up to which extent the diffusion patterns observed with the powder samples could again be recognized in the beads. In a second study the transport characteristics within binderless molecular sieves have been investigated, with the purpose to reveal differences in the diffusion behavior in comparison with their binder-containing counterparts.

No description available.

No description available.

Specific ion effects, identified for more than hundred years, play an important role in a wide range of phenomena and applications. Several mechanisms such as direct ion interaction with molecules have been suggested to explain these effects, but quantitative experimental evidence remains scarce. Electrophoretic NMR (eNMR) has been emerging as a very powerful tool for studying molecular association and ionic transport in a variety of systems. Yet its potential in studying specific ion effect has been unexplored. In this thesis, eNMR was in part developed further as an analytical method and was in part used as one of the main techniques to study ions interacting with macromolecules in aqueous and non-aqueous solutions. The complexation of a large group of cations with poly ethylene oxide (PEO) in methanol was studied with eNMR. The binding of monovalent ions was demonstrated not to follow the Hofmeister order; multivalent cations except barium all showed negligible complexation. As a unifying feature, only cations with surface charge density below a threshold value were able to bind suggesting that ion solvation is critical. The binding mechanism was examined in greater detail for K+ and Ba2+ with oligomeric PEO of different chain lengths. Those two cations exhibited different binding mechanisms. K+ was found to bind to PEO by having at least 6 repeating units wrap around it while retaining the polymer flexibility. On the other hand, Ba2+ (and, to some extent, (BaAnion)+) needs a slightly shorter section to bind, but the molecular dynamics at the binding site slow considerably. The binding of anions with poly (N-isopropylacrylamide) in water was quantified at low salt concentration with eNMR and the binding affinity, though very weak, followed the Hofmeister order. This result indicates the non-electrostatic nature of this specific ion effects. The increase of binding strength with salt concentration is well described by a Langmuir isotherm. The specific ion binding to a protein, bovine serum albumin (BSA), was also studied at pH values where BSA has either net positive and negative charges. Our results show that anions have the same binding affinity irrespective of the surface charge while the binding strength of cations is reversed with the change in net surface charge. This indicates different binding mechanisms for cations and anions. The ionization of cellobiose in alkaline solutions was measured quantitatively by eNMR. The results show a two-step deprotonation process with increasing alkaline strength. Supported by results from 1H-13C HSQC NMR and MD simulation, ionization was proposed to be responsible for the improved solubility of cellulose in alkaline solution. eNMR was also used to characterize the effective charge of tetramethylammonium ions in a variety of solvents. In solvents of high polarity, the results agree well with predictions based on Onsager’s limiting law but for nonpolar solvents deviations were found that were attributed to ion pair formation. / <p>QC 20170216</p>

This thesis deals with black carbon, its characteristic features and with its occurrence in chernozemic soils. In particular, this thesis deals with methods, which can study presence of black carbon in soils. The presence of black carbon and the whole composition of soil organic matter of three chernozemic soils in Czechia (Zeměchy, Tursko, Syrovice) is examined by 13 C NMR spectroscopy. Anthracological analysis of charcoal from fossil chernozems of Zemechy loess ravine deals with pedogenesis of chernozems and development of Quaternary vegetation in Central Europe. Coniferous tree species of Pinus sp., Pinus cf. cembra, Larix/Picea, Juniperus a Vaccicium, i.e. cold- and drought-tolerant taxa, were identified by anthracological analysis of soils of Zemechy loess ravine. The identified species suggest that the landscape around Zemechy was probably formed by parkland taiga. According to 13 C NMR spectroscopy, soil organic matter of fossil chernozem of Zemechy loess ravine consists particularly of alkyl and O-alkyl carbon. Aromatic carbon is also significant. O-alkyl carbon is the most important in the recent chernozems of Tursko and Syrovice. Aromatic carbon has the smallest proportion in both chernozems. The presence of aromatic carbon in chernozem of Tursko is the smallest of all analyzed soils. The...

Carbohydrates are essential biomolecules that decorate cell membranes and proteins in organisms. They are important both as structural elements and as identification markers. Many biological and pathogenic processes rely on the identification of carbohydrates by proteins, thereby making them attractive as molecular blueprints for drugs. This thesis describes how NMR spectroscopy can be utilized to study carbohydrates in solution at a molecular level. This versatile technique facilitates for investigations of (i) shapes, (ii) motions and (iii) interactions. A conformational study of an E. coli O-antigen was performed by calculating atomic distances from NMR NOESY experiments. The acquired data was utilized to validate MD simulations of the LPS embedded in a membrane. The agreement between experimental and calculated data was good and deviations were proven to arise from spin-diffusion. In another study presented herein, both the conformation and the dynamic behavior of amide side-chains linked to derivatives of D-Fucp3N, a sugar found in the O-antigen of bacteria, were investigated. J-couplings facilitated a conformational analysis and 13C saturation transfer NMR experiments were utilized to measure rate constants of amide cis-trans isomerizations. 13C NMR relaxation and 1H PFG diffusion measurements were carried out to explore and describe the molecular motion of mannofullerenes. The dominating motions of the mannofullerene spectral density were found to be related to pulsating motions of the linkers rather than global rotational diffusion. The promising inhibition of Ebola viruses identified for a larger mannofullerene can thus be explained by an efficient rebinding mechanism that arises from the observed flexibility in the linker. Molecular interactions between sugars and caffeine in water were studied by monitoring chemical shift displacements in titrations. The magnitude of the chemical shift displacements indicate that the binding occurs by a face to face stacking of the aromatic plane of caffeine to the ring plane of the sugar, and that the interaction is at least partly driven by solvation effects. Also, the binding of a Shigella flexneri serotype Y octasaccharide to a bacteriophage Sf6 tail spike protein was investigated. This interaction was studied by 1H STD NMR and trNOESY experiments. A quantitative analysis of the STD data was performed employing a newly developed method, CORCEMA-ST-CSD, that is able to simulate STD data more accurately since the line broadening of protein resonances are accounted for in the calculations. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Manuscript. Paper 4: Manuscript. Paper 5: Manuscript.</p>