Analysis of C cross-polarization magic angle spinning (CP/MAS) nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR), and X-ray powder diffraction data of trospium chloride (TCl) products crystallized from different mixtures of water-ethanol [φ(EtOH) = 0.5-1.0] at various temperatures (0°C, 20°C) and initial concentrations (saturated solution, 30%-50% excess of solvent) revealed extensive structural variability of TCl. Although (13) C CP/MAS NMR spectra indicated broad variety of structural phases arising from molecular disorder, temperature-modulated DSC identified presence of two distinct components in the products. FTIR spectra revealed alterations in the hydrogen bonding network (ionic hydrogen bond formation), whereas the X-ray diffraction reflected unchanged unit cell parameters. These results were explained by a two-component character of TCl products in which a dominant polymorphic form is accompanied by partly separated nanocrystalline domains of a secondary phase that does not provide clear Bragg reflections. These phases slightly differ in the degree of molecular disorder, in the quality of crystal lattice and hydrogen bonding network. It is also demonstrated that, for the quality control of such complex products, (13) C CP/MAS NMR spectroscopy combined with factor analysis (FA) can satisfactorily be used for categorizing the individual samples: FA of (13) C CP/MAS NMR spectra found clear relationships between the extent of molecular disorder and crystallization conditions. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 102:1235-1248, 2013.

• MeSH
• Benzilates chemistry   MeSH
• Calorimetry, Differential Scanning MeSH
• X-Ray Diffraction MeSH
• Crystallization MeSH
• Magnetic Resonance Spectroscopy MeSH
• Nortropanes chemistry   MeSH
• Powder Diffraction MeSH
• Spectroscopy, Fourier Transform Infrared MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Three 1,4,7,10-tetraazacyclododecane-based ligands disubstituted in 1,4-positions with phosphonic acid, phosphonate monoethyl-ester, and H-phosphinic acid pendant arms, 1,4-H4do2p, 1,4-H2do2pOEt, and 1,4-H2Bn2do2pH, were synthesized and their coordination to selected metal ions, Mg(II), Ca(II), Mn(II), Zn(II), Cu(II), Eu(III), Gd(III), and Tb(III), was investigated. The solid-state structure of the phosphonate ligand, 1,4-H4do2p, was determined by single-crystal X-ray diffraction. Protonation constants of the ligands and stability constants of their complexes were obtained by potentiometry, and their values are comparable to those of previously studied analogous 1,7-disubstitued cyclen derivatives. The Gd(III) complex of 1,4-H4do2p is ~1 order of magnitude more stable than the Gd(III) complex of the 1,7-analogue, probably due to the disubstituted ethylenediamine-like structural motif in 1,4-H4do2p enabling more efficient wrapping of the metal ion. Stability of Gd(III)-1,4-H2do2pOEt and Gd(III)-H2Bn2do2pH complexes is low and the constants cannot be determined due to precipitation of the metal hydroxide. Protonations of the Cu(II), Zn(II), and Gd(III) complexes probably takes place on the coordinated phosphonate groups. Complexes of Mn(II) and alkali-earth metal ions are significantly less stable and are not formed in acidic solutions. Potential presence of water molecule(s) in the coordination spheres of the Mn(II) and Ln(III) complexes was studied by variable-temperature NMR experiments. The Mn(II) complexes of the ligands are not hydrated. The Gd(III)-1,4-H4do2p complex undergoes hydration equilibrium between mono- and bis-hydrated species. Presence of two-species equilibrium was confirmed by UV-Vis spectroscopy of the Eu(III)-1,4-H4do2p complex and hydration states were also determined by luminescence measurements of the Eu(III)/Tb(III)-1,4-H4do2p complexes.

• MeSH
• Europium chemistry   MeSH
• Gadolinium chemistry   MeSH
• Heterocyclic Compounds chemistry   MeSH
• Coordination Complexes chemical synthesis   chemistry   MeSH
• Contrast Media MeSH
• Crystallography, X-Ray MeSH
• Phosphinic Acids chemistry   MeSH
• Ligands MeSH
• Magnetic Resonance Spectroscopy MeSH
• Manganese chemistry   MeSH
• Organophosphonates chemistry   MeSH
• Potentiometry MeSH
• Spectrophotometry, Ultraviolet MeSH
• Temperature MeSH
• Publication type
• Journal Article MeSH

Supramolecular characteristics of two spermine amides of betulinic acid (1 and 2) were studied by measuring and evaluating their UV-VIS-NIR spectra in aqueous acetonitrile and DOSY-NMR spectra in tetradeuteromethanol, accompanied by atomic force microscopy (AFM) images, scanning electron microscopy (SEM) micrographs, and transmission electron microscopy (TEM) micrographs. Fibrous supramolecular self-assembly of 1 and 2 was observed by AFM images, as well as by the SEM and TEM micrographs. Bathochromic shifts of the absorbance maximum at 870nm to 1015-970nm in the UV-VIS-NIR spectra were observed with increasing water content in the acetonitrile/water systems, indicating formation of fibrous J-type aggregates. Variable temperature DOSY-NMR spectral measurement showed non-linear dependence that also suggests self-assembly behavior of the studied systems. Chiral supramolecular structures were formed by self-assembling due to the chirality of the monomeric molecules. Application of aqueous media during self-assembly procedures is an important factor in the development of targeted drug delivery systems.

• MeSH
• Amides chemistry   MeSH
• Magnetic Resonance Spectroscopy MeSH
• Microscopy, Atomic Force MeSH
• Molecular Structure MeSH
• Microscopy, Electrochemical, Scanning MeSH
• Spermine chemistry   MeSH
• Microscopy, Electron, Transmission MeSH
• Triterpenes chemistry   MeSH
• Publication type
• Journal Article MeSH

Tautomerism of nucleic acid (NA) bases is a crucial factor for the maintenance and translation of genetic information in organisms. Only canonical tautomers of NA bases can form hydrogen-bonded complexes with their natural counterparts. On the other hand, rare tautomers of nucleobases have been proposed to be involved in processes catalysed by NA enzymes. Isocytosine, which can be considered as a structural fragment of guanine, is known to have two stable tautomers both in solution and solid states. The tautomer equilibrium of isocytosine contrasts with the remarkable stability of the canonical tautomer of guanine. This paper investigates the factors contributing to the stability of the canonical tautomer of guanine by a combination of NMR experiments and theoretical calculations. The electronic effects of substituents on the stability of the rare tautomers of isocytosine and guanine derivatives are studied by density functional theory (DFT) calculations. Selected derivatives are studied by variable-temperature NMR spectroscopy. Rare tautomers can be stabilised in solution by intermolecular hydrogen-bonding interactions with suitable partners. These intermolecular interactions give rise to characteristic signals in proton NMR spectra, which make it possible to undoubtedly confirm the presence of a rare tautomer.

• MeSH
• Cytosine analogs & derivatives   chemistry   MeSH
• Dimerization MeSH
• DNA chemistry   MeSH
• Electrons MeSH
• Guanine chemistry   MeSH
• Quantum Theory MeSH
• Magnetic Resonance Spectroscopy methods   MeSH
• Macromolecular Substances MeSH
• Normal Distribution MeSH
• Reproducibility of Results MeSH
• Stereoisomerism MeSH
• Thermodynamics MeSH
• Hydrogen chemistry   MeSH
• Hydrogen Bonding MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Two new macrocyclic DOTA-like chelates containing one phosphonate pendant arm were synthesised as potential contrast agents for MRI (magnetic resonance imaging). The chelates bind to the lanthanide(III) in an octadentate manner, via four nitrogen atoms, three carboxylate and one phosphonate oxygen atoms. Solution structures of [Ln(do3ap(OEt2))(H(2)O)] and [Ln(do3ap(OEt))(H(2)O)](-) were studied using (31)P and (1)H NMR spectroscopy and SAP (square-antiprismatic)/TSAP (twisted square-antiprismatic) isomerism was observed. Depending on the nature of the lanthanide(III) ion, the lanthanide(III) complexes of H(4)do3ap(OEt) are present in solution as up to four different diastereoisomers observable with NMR. The TSAP isomer is the most abundant at the beginning of the lanthanide series and, with a decrease of the ionic radius of lanthanide(III) ions, both TSAP and SAP forms were observed. A second interconversion (SAP<-->TSAP') becomes important at the end of the series (TSAP' means the TSAP species without a coordinated water molecule). The remaining axial coordination site is occupied by one water molecule for the Gd(3+)-complex. The calculated fraction of the TSAP isomer in the gadolinium(III) complexes increases in the order [Gd(DOTA)(H(2)O)](-) < [Gd(do3ap(OEt2))(H(2)O)] < [Gd(do3ap(OEt))(H(2)O)](-) < [Gd(do3ap)(H(2)O)](2-). Gadolinium(III) complexes of phosphorus-containing chelates, generally, have the advantage of a relatively fast water exchange rate due to a greater sterical demand of the phosphorus acid moiety and of the presence of the second-sphere water shell, which also contributes to the overall relaxivity. The [Gd(do3ap(OEt2))(H(2)O)] and [Gd(do3ap(OEt))(H(2)O)](-) complexes were studied by variable-temperature (17)O NMR and (1)H NMRD. The experimental data were evaluated simultaneously with commonly used equations based on Solomon-Bloembergen-Morgan approximation, extended by a contribution of the second coordination sphere. The water exchange rates were found to be strongly dependent on the TSAP/SAP isomeric ratio and the overall charge of the complex: the monoanionic [Gd(do3ap(OEt))(H(2)O)](-) complex with TSAP molar fraction equal to 0.36 has the water exchange rate of 20 x 10(6) s(-1) (tau(M) = 50 ns) while neutral [Gd(do3ap(OEt2))(H(2)O)] complex with TSAP molar fraction 0.28 has an exchange rate equal to 4.4 x 10(6) s(-1) (tau(M) = 227 ns).

• MeSH
• Financing, Organized MeSH
• Gadolinium chemistry   MeSH
• Heterocyclic Compounds, 1-Ring chemistry   MeSH
• Contrast Media chemical synthesis   MeSH
• Magnetic Resonance Spectroscopy methods   MeSH
• Models, Molecular MeSH
• Molecular Structure MeSH
• Organophosphonates chemistry   MeSH
• Organometallic Compounds chemical synthesis   MeSH
• Solutions MeSH
• Water chemistry   MeSH

Iron complexes (1-7) involving N6-benzyladenosine derivatives of the predominant composition [Fe(L(n))Cl(3)].H(2)O {where L(1)=N6-(2-fluorobenzyl)adenosine (1), L(2)=N6-(4-fluorobenzyl)adenosine (2), L(3)=N6-(2-trifluoromethylbenzyl)adenosine (3), L(4)=N6-(3-trifluoromethylbenzyl)adenosine (4), L(5)=N6-(4-trifluoromethylbenzyl)adenosine (5), L(6)=N6-(4-trifluoromethoxybenzyl)adenosine (6), and L(7)=N6-(4-chlorobenzyl)adenosine (7)} have been synthesized. The compounds have been characterized by elemental analysis, variable-temperature and in-field 57Fe Mossbauer, ES+ MS, FTIR, 1H and 13C NMR spectroscopies, magnetochemical and conductivity measurements, thermal (TGA/DSC/DTA) analyses, and DFT calculations. It has been found that the organic molecule is coordinated to iron via N7 atom of the appropriate adenosine derivative and the products are represented by mixtures of complexes with various iron oxidation (Fe(III)/Fe(II)) and spin states (S=5/2, 4/2, 3/2, 2/2) and geometries (tetrahedral or trigonal bipyramidal). It is caused by the fact that partial redox processes proceed during the reactions due to the presence of a ribose moiety, which is oxidized to the corresponding 5'-ribotic acid, and simultaneously, a portion of Fe(III) cations is reduced to Fe(II) ones. Moreover, a significant effect of crystal water molecules on stereochemistry, and hence, on magnetic and spectral properties of the prepared complexes has been found. The compounds have been tested for their in vitro cytotoxicity against the following human cancer cell lines: malignant melanoma (G-361), osteogenic sarcoma (HOS), chronic myelogenous leukemia (K-562), and breast adenocarcinoma (MCF-7). The most important results have been obtained for complex 2 with IC(50) values 8-16 microM against HOS, K-562, and MCF-7 cell lines, and for complex 6 with IC(50) value 4 microM against MCF-7 cell line.

• MeSH
• Adenosine analogs & derivatives   pharmacology   chemical synthesis   MeSH
• Algorithms MeSH
• Financing, Organized MeSH
• Spectrometry, Mass, Electrospray Ionization MeSH
• Inhibitory Concentration 50 MeSH
• Humans MeSH
• Magnetic Resonance Spectroscopy MeSH
• Magnetics MeSH
• Cell Line, Tumor MeSH
• Organometallic Compounds pharmacology   chemical synthesis   MeSH
• Spectrophotometry, Infrared MeSH
• Spectroscopy, Mossbauer MeSH
• Iron chemistry   MeSH
• Check Tag
• Humans MeSH

Naturally occurring acylated β-sitosteryl glucosides have been investigated for their novel properties. The synthetic protocol based on the literature data was improved and optimized. The main improvement consists in employing systems of ionic liquids combined with organic solvents in lipase-mediated esterification of (3β)-stigmast-5-en-3-yl β-d-glucopyranoside to get (3β)-stigmast-5-en-3-yl 6-O-acyl-β-d-glucopyranosides. Maximum yields of these products were achieved with Candida antarctica lipase B immobilized on Immobead 150, recombinant from yeast, in absolute THF and in the presence of either ionic liquid [1-butyl-3-methyl imidazolium tetrafluoroborate ([BMIM]BF4) or 1-butyl-3-methyl imidazolium hexafluorophosphate ([BMIM]PF6)] employed. Pharmacological activity of (3β)-stigmast-5-en-3-yl 6-O-acyl-β-d-glucopyranosides was studied in tests on MCF7 tumor cell lines; the compounds displayed moderate activity which was higher than the activity of β-sitosterol. Supramolecular characteristics were discovered at (3β)-stigmast-5-en-3-yl 6-O-dodecanoyl-β-d-glucopyranoside that formed supramolecular polymer through multiple H-bonds in a methanol/water system (60/40). Its formation was confirmed by the independent UV-vis measurements during certain time period, by variable temperature DOSY-NMR measurement in deuteriochloroform, and visualized by transmission electron microscopy (TEM) and atomic force microscopy (AFM) showing chiral helical structures and complex superassembly systems based on fibrous supramolecular polymer. In contrary, no such properties have been observed for the other two (3β)-stigmast-5-en-3-yl 6-O-acyl-β-d-glucopyranosides under the given experimental conditions.

• MeSH
• Ionic Liquids chemistry   MeSH
• Humans MeSH
• Lipase metabolism   MeSH
• Magnetic Resonance Spectroscopy MeSH
• MCF-7 Cells MeSH
• Microscopy, Atomic Force MeSH
• Sitosterols chemistry   metabolism   pharmacology   MeSH
• Microscopy, Electron, Transmission MeSH
• Cell Survival drug effects   MeSH
• Hydrogen Bonding MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH

Diagnostika příčiny oběhové zástavy u pacientů do 35 let nemusí být snadná. Řada onemocnění vedoucích k oběhové zástavě v nižším věku je hereditárních, s monogenním typem dědičnosti – kardiomyopatie, kanálopatie. Jejich odhalení znesnadňuje i nízká penetrance kauzální genové mutace a rozdílná expresivita. V případě arytmogenní kardiomyopatie je náhlá srdeční smrt či oběhová zástava často první manifestací onemocnění, před rozvinutím výraznějšího strukturálního postižení srdce. Kazuistické sdělení prezentuje případ 27letého sportovce, u kterého došlo k oběhové zástavě s úspěšnou kardiopulmonální resuscitací během soutěžního fotbalového utkání. Přestože na základě provedených zobrazovacích vyšetření nebylo patrné strukturální srdeční onemocnění a nebyla ani naplněna diagnostická kritéria arytmogenní kardiomyopatie, genetické vyšetření formou sekvenování DNA nové generace prokázalo mutaci genu pro desmosomální protein plakophilin 2. Mutační varianty tohoto proteinu patří k nejčastějšímu molekulárnímu podkladu arytmogenní kardiomyopatie. Rozšíření genetického testování v kardiologii může mít výrazný vliv nejen na zpřesnění diagnostiky příčiny oběhové zástavy u přeživších mladých nemocných, ale i na rizikovou stratifikaci blízkých příbuzných probanda.

Diagnosing of the cause of out-of-hospital cardiac arrest in young patients ˂ 35 years old is challenging. Some disorders leading to cardiac arrest have monogenic type of heredity – cardiomyopathies, channelopathies. Diagnostic process may be complicated by low penetrance of causal gene mutation and variable expression. Sudden cardiac death or cardiac arrest often appear as the first clinical manifestation or arrhythmogenic cardiomyopathy before the development of obvious structural heart disease. The case re- port presents 27-year-old male athlete who underwent out-of-hospital cardiac arrest with successful cardiopulmonary resuscitation during soccer match. Despite the fact that there were no signs of structural heart impairment according to cardiac imaging and diagnostic criteria for arrhythmogenic right ventricular cardiomyopathy were not fulfilled, genetic testing using next-generation DnA sequencing revealed gene mutation in desmosome protein plakophilin 2, which represents the most frequent molecular background of arrhythmogenic cardiomyopathy. Extension of molecular testing in cardiology may contribute to more precise detection of the causal disease in young surviving patients who experienced cardiac arrest, as well as better risk stratification of their relatives.

• MeSH
• Acidosis diagnosis   MeSH
• Medical History Taking MeSH
• Arrhythmogenic Right Ventricular Dysplasia diagnosis   etiology   complications   MeSH
• Pneumonia, Aspiration MeSH
• Diagnosis, Differential MeSH
• Adult MeSH
• Electric Countershock MeSH
• Electrocardiography MeSH
• Ventricular Fibrillation diagnosis   MeSH
• Soccer MeSH
• Genetic Testing MeSH
• Cardiopulmonary Resuscitation MeSH
• Tachycardia, Ventricular diagnosis   drug therapy   complications   MeSH
• Ventricular Premature Complexes diagnosis   complications   MeSH
• Humans MeSH
• Magnetic Resonance Imaging MeSH
• Metoprolol administration & dosage   MeSH
• Mutation MeSH
• Death, Sudden, Cardiac * etiology   prevention & control   MeSH
• Treatment Failure MeSH
• Plakophilins genetics   MeSH
• Heart diagnostic imaging   MeSH
• Hypothermia, Induced MeSH
• High-Throughput Nucleotide Sequencing MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Male MeSH
• Publication type
• Case Reports MeSH
• Research Support, Non-U.S. Gov't MeSH

• MeSH
• Biophysics MeSH
• Radiography MeSH
• Radiology MeSH
• Radiotherapy MeSH
• Publication type
• Congress MeSH
• Collected Work MeSH

• Conspectus
• Lékařské vědy. Lékařství
• NML Fields
• fyzika, biofyzika
• radiologie, nukleární medicína a zobrazovací metody

• MeSH
• Chemistry MeSH

• Conspectus
• Organická chemie
• NML Fields
• chemie, klinická chemie
• NML Publication type
• učebnice vysokých škol