Hydrogen bond formation may enhance RDC-based discrimination of enantiomers.

The distinction of enantiomers based on residual anisotropic parameters obtained by alignment in chiral poly-γ-benzyl-L-glutamate (PBLG) is among the strongest in high-resolution NMR spectroscopy. However, large variations in enantiodifferentiation among different solutes are frequently observed. One hypothesis is that the formation of hydrogen bonds between solute and PBLG is important for the distinction of enantiomers.

Heterobimetallic Eu(iii)/Pt(ii) single-chain nanoparticles: a path to enlighten catalytic reactions.

We introduce the formation and characterization of heterometallic single-chain nanoparticles entailing both catalytic and luminescent properties. A terpolymer containing two divergent ligand moieties, phosphines and phosphine oxides, is synthesized and intramolecularly folded into nanoparticles a selective metal complexation of Pt(ii) and Eu(iii). The formation of heterometallic Eu(iii)/Pt(ii) nanoparticles is evidenced by size exclusion chromatography, multinuclear NMR (H, P{H}, F, Pt) as well as diffusion-ordered NMR and IR spectroscopy.

Determination of Configuration and Conformation of a Reserpine Derivative with Seven Stereogenic Centers Using Molecular Dynamics with RDC-Derived Tensorial Constraints*.

NMR-based determination of the configuration of complex molecules containing many stereocenters is often not possible using traditional NOE data and coupling patterns. Making use of residual dipolar couplings (RDCs), we were able to determine the relative configuration of a natural product containing seven stereocenters, including a chiral amine lacking direct RDC data. To identify the correct relative configuration out of 32 possible ones, experimental RDCs were used in three different approaches for data interpretation: by fitting experimental data based singular value decomposition (SVD) using a single alignment tensor and either (i) a single conformer or (ii) multiple conformers, or alternatively (iii) using molecular dynamics simulations with tensorial orientational constraints (MDOC).

The simulation of NMR data of flexible molecules: sagittamide A as an example for MD simulations with orientational constraints.

The recently developed MDOC (Molecular Dynamics with Orientational Constraints) simulation is applied for the first time to a fully flexible molecule. MDOC simulations aim to single out the naturally existing configuration of molecules and to elucidate conformer populations. The performance of the method was first demonstrated on a well-studied test case, the five-membered ring lactone (α-methylene-γ-butyrolactone).

Configuration determination by residual dipolar couplings: accessing the full conformational space by molecular dynamics with tensorial constraints.

Residual dipolar couplings (RDCs) and other residual anisotropic NMR parameters provide valuable structural information of high quality and quantity, bringing detailed structural models of flexible molecules in solution in reach. The corresponding data interpretation so far is directly or indirectly based on the concept of a molecular alignment tensor, which, however, is ill-defined for flexible molecules. The concept is typically applied to a single or a small set of lowest energy structures, ignoring the effect of vibrational averaging.

Efficient Extraction from Mice Feces for NMR Metabolomics Measurements with Special Emphasis on SCFAs.

Nuclear magnetic resonance (NMR) spectroscopy is one of the most promising methods for use in metabolomics studies as it is able to perform non targeted measurement of metabolites in a quantitative and non-destructive way. Sample preparation of liquid samples like urine or blood serum is comparatively easy in NMR metabolomics, because mainly buffer and chemical shift reference substance are added. For solid samples like feces suitable extraction protocols need to be defined as initial step, where the exact protocol depends on sample type and features.

Borane-Catalyzed Synthesis of Quinolines Bearing Tetrasubstituted Stereocenters by Hydride Abstraction-Induced Electrocyclization.

The borane-catalyzed synthesis of quinoline derivatives bearing tetrasubstituted stereocenters from vinyl anilines has been developed. Mechanistic studies and quantum-mechanical investigations support the hydride abstraction/electrocyclization/hydride addition mechanism. The products were obtained in up to 99 % yield with a diastereoselectivity of >99 % in favour for the 3a-5-cis isomer.

Phenanthroline-A Versatile Ligand for Advanced Functional Polymeric Materials.

The controlled incorporation of phenanthroline moieties into polymers is introduced, demonstrating their application as metal-ion complexing ligands for the construction of advanced macromolecular structures. Specifically, two phenanthroline-containing monomers based on acrylate and styrene functionalities, were synthesized. Each monomer was readily copolymerized with either N,N-dimethylacrylamide or styrene via nitroxide-mediated polymerization, resulting in narrowly distributed polar or non-polar copolymers.

Controlling orthogonal self-assembly through cis-trans isomerization of a non-covalent palladium complex dimer.

The trans-configured square-planar complex of dichloropalladium and chiral monodentate phosphine ligands forms self-complementary dimers through 16 hydrogen bonded amides and π-π stacking in chlorinated solvents. The self-assembly is controlled by cis-trans isomerisation of the metal center, where the trans-configuration governs the dimer formation.

Metabolite patterns predicting sex and age in participants of the Karlsruhe Metabolomics and Nutrition (KarMeN) study.

Physiological and functional parameters, such as body composition, or physical fitness are known to differ between men and women and to change with age. The goal of this study was to investigate how sex and age-related physiological conditions are reflected in the metabolome of healthy humans and whether sex and age can be predicted based on the plasma and urine metabolite profiles. In the cross-sectional KarMeN (Karlsruhe Metabolomics and Nutrition) study 301 healthy men and women aged 18-80 years were recruited.

Degradable fluorescent single-chain nanoparticles based on metathesis polymers.

We introduce the facile synthesis of fluorescent single-chain nanoparticles (SCNPs) based on chain-shattering acyclic diene metathesis (ADMET) polymers featuring self-immolative azobenzene motifs. An electrophilic alkoxyetherification is utilized to introduce the photoreactive moieties required for the subsequent chain collapse via UV-induced nitrile imine-mediated tetrazole-ene cycloaddition (NITEC).

Untargeted NMR Spectroscopic Analysis of the Metabolic Variety of New Apple Cultivars.

Metabolome analyses by NMR spectroscopy can be used in quality control by generating unique fingerprints of different species. Hundreds of components and their variation between different samples can be analyzed in a few minutes/hours with high accuracy and low cost of sample preparation. Here, apple peel and pulp extracts of a variety of apple cultivars were studied to assess their suitability to discriminate between the different varieties.

Q.E.COSY: determining sign and size of small deuterium residual quadrupolar couplings using an extended E.COSY principle.

Residual quadrupolar couplings contain important structural information comparable with residual dipolar couplings. However, the measurement of sign and size of especially small residual quadrupolar couplings is difficult. Here, we present an extension of the E.

Correlations between lithium local structure and electrochemistry of layered LiCo(1-2x)Ni(x)Mn(x)O2 oxides: 7Li MAS NMR and EPR studies.

Advanced (7)Li MAS NMR technologies and high frequency EPR are combined to identify structural motifs and their relation to electrochemical properties of layered lithium-cobalt-nickel-manganese oxides LiCo1-2xNixMnxO2 (0 < x ≤ 0.5) used as cathode materials in lithium ion batteries. Structural-chemical shift regularities were established by systematic variation of the ratio of diamagnetic Co(3+) to paramagnetic Ni/Mn ions with variable valences.

Formation of a polymer surface with a gradient of pore size using a microfluidic chip.

Here we demonstrate the generation of polymer monolithic surfaces possessing a gradient of pore and polymer globule sizes from ~0.1 to ~0.5 μm defined by the composition of two polymerization mixtures injected into a microfluidic chip.

Configuration verification via RDCs on the example of a tetra-substituted pyrrolidine ring.

The configurational analysis of organic compounds is an important application for high resolution NMR spectroscopy. In the present study, a tetra-substituted pyrrolidine with four chiral carbon atoms is analyzed using classical methods based on (3) J and NOE data in solution and compared and verified with recently introduced alternative approaches via residual dipolar couplings (RDCs) in two weak anisotropic alignment media. The molecule shows sufficient rigidity in the five-membered ring for the configurational characterization with the various techniques.

Synthesis and in vitro antimycobacterial activity of compounds derived from (R)- and (S)-2-amino-1-butanol - The crucial role of the configuration.

The synthesis of 47 structurally diverse compounds incorporating the (R)-2-amino-1-butanol motif has been realized. Ten of these compounds were found to exhibit in vitro specific activity against Mycobacterium tuberculosis H37Rv in a MIC range of 0.65 μM-14.

High-frequency electron paramagnetic resonance analysis of the oxidation state and local structure of Ni and Mn ions in Ni,Mn-codoped LiCoO(2).

High-frequency electron paramagnetic resonance (HF-EPR) spectroscopy was employed to examine the oxidation state and local structure of Ni and Mn ions in Ni,Mn-codoped LiCoO(2). The assignment of EPR signals was based on Mg,Mn-codoped LiCoO(2) and Ni-doped LiCoO(2) used as Mn(4+) and low-spin Ni(3+) EPR references. Complementary information on the oxidation state of transition-metal ions was obtained by solid-state (6,7)Li NMR spectroscopy.

[Male genital system diseases and degree of fertilizing ability].

This study includes 1302 patients with congenital, inflammatory and vascular diseases of male genital system and proved man fertilizing ability mination of the prognostic factors and administration of complex approach in the treatment of every patient.

[Azoospermia and male genital diseases].

This study includes 1227 patients with congenital, inflammatory and vascular diseases of male genital system and proved the frequency of azoospermia.

Congenital anomalies of the mesonephric duct and fertility.

Unlabelled: Agenesia of deferential duct and the others congenital malformations of mesonephronical duct are often encountering condition in andrological practice. This study presents the possibilities of reproductive medicine to restore the male fertility and concentrates on biological and clinical aspects of malformations of mesonephronic duct like factors for excretory male infertility. The investigations including 104 patients (mean age 30.

P.E.HSQC: a simple experiment for simultaneous and sign-sensitive measurement of (1JCH+DCH) and (2JHH+DHH) couplings.

The angular information content of residual dipolar couplings between nuclei of fixed distance makes the accurate and sign-sensitive measurement of (1JCH+DCH) and (2JHH+DHH) couplings highly desirable. Experiments published so far are typically highly specialized for the effective measurement of a subset of couplings. The P.

Tuberculosis of male genital system--myth or reality in 21st century.

To review literature and our clinical experience with tuberculosis (TBC) of male genital tract. To analyze the localization of the specific process, association with other forms of TBC and its impact on fertility. The study comprises 69 male patients, average age 40.

Effects of cigarette smoking on sperm plasma membrane integrity and DNA fragmentation.

Cigarette smoking is a serious health problem of our society. It is known that cigarette smoke is a cell mutagen and carcinogen, and that it may affect adversely male fertility. The possible detrimental effects on sperm cells are of great interest but the data available to support this statement are somewhat elusive.

Diagnosis of abdominal bilateral cryptorchidism: HCG stimulation test.

A diagnostic stimulation test with hCG (Pregnyl) was performed in clinically healthy boys and was used to diagnose cases of bilateral abdominal cryptorchidism. In clinical andrology, this test may be applied as a noninvasive and highly sensitive method.