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Sample records for 1h-1h cosy hmqc

  1. "Perfect echo" HMQC: sensitivity and resolution enhancement by broadband homonuclear decoupling.

    PubMed

    Baishya, Bikash; Khetrapal, C L; Dey, Krishna Kishor

    2013-09-01

    Homonuclear (1)H-(1)H J-modulation leads to J-multiplets in F1 dimension of 2D (1)H-(13)C HMQC spectra. This hampers unambiguous signal assignment for overcrowded (13)C spectra. Broadband homonuclear decoupling has been achieved in the indirect t1 evolution period by incorporating blocks of perfect echo. This method of perfect echo HMQC demonstrates better resolution and sensitivity than conventional HMQC spectra. The results on Cyclosporine demonstrate that the method is very efficient for refocusing geminal couplings in weakly coupled -(13)CH2 groups. Partial refocusing of vicinal couplings is also observed for -(13)CH and -(13)CH3 groups. Interpretation of the result based on product operator formalism is also given. Comparison of pe-HMQC, HMQC and HSQC reveals that the F1 linewidth of pe-HMQC is much narrower than HMQC and very close to that of HSQC for CH2 groups.

  2. Simple Approaches for Estimating Vicinal 1H- 1H Coupling-Constants and for Obtaining Stereospecific Resonance Assignments in Leucine Side Chains

    NASA Astrophysics Data System (ADS)

    Constantine, K. L.; Friedrichs, M. S.; Mueller, L.

    An approach for deriving stereospecific δ-methyl assignments and χ 2 dihedral angle constraints for leucine residues, based on easily recognized patterns of 1H- 1H spin-spin coupling constants and intraresidue nuclear-Overhauser-effect spectroscopy (NOESY) cross-peak intensities, is described. The approach depends on resolved H γ and/or δ-methyl resonances and on initially obtaining stereospecific assignments for H β2 and H β3. As part of the overall strategy, a method is presented for obtaining qualitative or, in favorable cases, semiquantitative estimates of vicinal 1H- 1H coupling constants from peak intensities measured in a short-mixing-time 1H- 1H total correlation spectroscopy (TOCSY) experiment. This method of estimating 1H- 1H spin-spin coupling constants is generally applicable to all side-chain types. The approach is illustrated for several leucine residues within uniformly 15N-labeled and 15N/ 13C-double-labeled isolated light-chain variable domain of the anti-digoxin antibody 26-10. Estimates of 3Jαβ and 3Jβγ coupling constants are derived from a three-dimensional (3D) 13C-edited TOCSY-heteronuclear multiple-quantum coherence (HMQC) spectrum. These data are combined with information from 3D 15N-edited NOESY and 3D 13C-edited NOESY spectra to yield stereospecific H β2, H β3, and δ-methyl assignments, as well as constraints on χ (1) and χ 2 dihedral angles. Although the overall approach is illustrated using 3D 15N-edited and 13C-edited data, it is equally applicable to analysis of two-dimensional 1H- 1H NOESY and TOCSY spectra.

  3. Proton-detected 3D 14N/14N/1H isotropic shift correlation experiment mediated through 1H-1H RFDR mixing on a natural abundant sample under ultrafast MAS

    NASA Astrophysics Data System (ADS)

    Pandey, Manoj Kumar; Nishiyama, Yusuke

    2015-09-01

    In this contribution, we have demonstrated a proton detection-based approach on a natural abundant powdered L-Histidine HCl-H2O sample at ultrafast magic angle spinning (MAS) to accomplish 14N/14N correlation from a 3D 14N/14N/1H isotropic shift correlation experiment mediated through 1H finite-pulse radio frequency-driven recoupling (fp-RFDR). Herein the heteronuclear magnetization transfer between 14N and 1H has been achieved by HMQC experiment, whereas 14N/14N correlation is attained through enhanced 1H-1H spin diffusion process due to 1H-1H dipolar recoupling during the RFDR mixing. While the use of ultrafast MAS (90 kHz) provides sensitivity enhancement through increased 1H transverse relaxation time (T2), the use of micro-coil probe which can withstand strong 14N radio frequency (RF) fields further improves the sensitivity per unit sample volume.

  4. 1H-detected 1H- 1H correlation spectroscopy of a stereo-array isotope labeled amino acid under fast magic-angle spinning

    NASA Astrophysics Data System (ADS)

    Takahashi, Hiroki; Kainosho, Masatsune; Akutsu, Hideo; Fujiwara, Toshimichi

    2010-04-01

    The combined use of selective deuteration, stereo-array isotope labeling (SAIL), and fast magic-angle spinning effectively suppresses the 1H-1H dipolar couplings in organic solids. This method provided the high-field 1H NMR linewidths comparable to those achieved by combined rotation and multiple-pulse spectroscopy. This technique was applied to two-dimensional 1H-detected 1H-1H polarization transfer CHH experiments of valine. The signal sensitivity for the 1H-detected CHH experiments was greater than that for the 13C-detected 1H-1H polarization transfer experiments by a factor of 2-4. We obtained the 1H-1H distances in SAIL valine by CHH experiments with an accuracy of about 0.2 Å by using a theory developed for 1H-1H polarization transfer in 13C-labeled organic compounds.

  5. Three-Dimensional Maximum-Quantum Correlation HMQC NMR Spectroscopy (3D MAXY-HMQC)

    NASA Astrophysics Data System (ADS)

    Liu, Maili; Mao, Xi-An; Ye, Chaohui; Nicholson, Jeremy K.; Lindon, John C.

    1997-11-01

    The extension of two-dimensional maximum-quantum correlation spectroscopy (2D MAXY NMR), which can be used to simplify complex NMR spectra, to three dimensions (3D) is described. A new pulse sequence for 3D MAXY-HMQC is presented and exemplified using the steroid drug dexamethasone. The sensitivity and coherence transfer efficiency of the MAXY NMR approach has also been assessed in relation to other HMQC- and HSQC-based 3D methods.

  6. Crystal structure of 1H,1'H-[2,2'-biimid-azol]-3-ium hydrogen tartrate hemi-hydrate.

    PubMed

    Gao, Xiao-Li; Bian, Li-Fang; Guo, Shao-Wei

    2014-11-01

    In the crystal of the title hydrated salt, C6H7N4 (+)·C4H5O6 (-)·0.5H2O, the bi-imidazole monocation, 1H,1'H-[2,2'-biimidazol]-3-ium, is hydrogen bonded, via N-H⋯O, O-H⋯O and O-H⋯N hydrogen bonds, to the hydrogen tartrate anion and the water mol-ecule, which is located on a twofold rotation axis, forming sheets parallel to (001). The sheets are linked via C-H⋯O hydrogen bonds, forming a three-dimensional structure. There are also C=O⋯π inter-actions present [O⋯π distances are 3.00 (9) and 3.21 (7) Å], involving the carbonyl O atoms and the imidazolium ring, which may help to consolidate the structure. In the cation, the dihedral angle between the rings is 11.6 (2)°.

  7. Dynamics-based selective 2D 1H/1H chemical shift correlation spectroscopy under ultrafast MAS conditions

    NASA Astrophysics Data System (ADS)

    Zhang, Rongchun; Ramamoorthy, Ayyalusamy

    2015-05-01

    Dynamics plays important roles in determining the physical, chemical, and functional properties of a variety of chemical and biological materials. However, a material (such as a polymer) generally has mobile and rigid regions in order to have high strength and toughness at the same time. Therefore, it is difficult to measure the role of mobile phase without being affected by the rigid components. Herein, we propose a highly sensitive solid-state NMR approach that utilizes a dipolar-coupling based filter (composed of 12 equally spaced 90° RF pulses) to selectively measure the correlation of 1H chemical shifts from the mobile regions of a material. It is interesting to find that the rotor-synchronized dipolar filter strength decreases with increasing inter-pulse delay between the 90° pulses, whereas the dipolar filter strength increases with increasing inter-pulse delay under static conditions. In this study, we also demonstrate the unique advantages of proton-detection under ultrafast magic-angle-spinning conditions to enhance the spectral resolution and sensitivity for studies on small molecules as well as multi-phase polymers. Our results further demonstrate the use of finite-pulse radio-frequency driven recoupling pulse sequence to efficiently recouple weak proton-proton dipolar couplings in the dynamic regions of a molecule and to facilitate the fast acquisition of 1H/1H correlation spectrum compared to the traditional 2D NOESY (Nuclear Overhauser effect spectroscopy) experiment. We believe that the proposed approach is beneficial to study mobile components in multi-phase systems, such as block copolymers, polymer blends, nanocomposites, heterogeneous amyloid mixture of oligomers and fibers, and other materials.

  8. Fast and simultaneous determination of (1) H-(1) H and (1) H-(19) F scalar couplings in complex spin systems: Application of PSYCHE homonuclear broadband decoupling.

    PubMed

    Kakita, Veera Mohana Rao; Rachineni, Kavitha; Hosur, Ramakrishna V

    2017-07-21

    The present manuscript focuses on fast and simultaneous determination of (1) H-(1) H and (1) H-(19) F scalar couplings in fluorinated complex steroid molecules. Incorporation of broadband PSYCHE homonuclear decoupling in the indirect dimension of zero-quantum filtered diagonal experiments (F1-PSYCHE-DIAG) suppresses (1) H-(1) H scalar couplings; however, it retains (1) H-(19) F scalar couplings (along F1 dimension) for the (19) F coupled protons while preserving the pure-shift nature for (1) H resonances uncoupled to (19) F. In such cases, along the direct dimensions, (1) H-(1) H scalar coupling multiplets deconvolute and they appear as duplicated multiplets for the (19) F coupled protons, which facilitates unambiguous discrimination of (19) F coupled (1) H chemical sites from the others. Further, as an added advantage, data acquisition has been accelerated by invoking the known ideas of spectral aliasing in the F1-PSYCHE-DIAG scheme and experiments demand only ~10 min of spectrometer times. Copyright © 2017 John Wiley & Sons, Ltd.

  9. Proton-detected 3D (15)N/(1)H/(1)H isotropic/anisotropic/isotropic chemical shift correlation solid-state NMR at 70kHz MAS.

    PubMed

    Pandey, Manoj Kumar; Yarava, Jayasubba Reddy; Zhang, Rongchun; Ramamoorthy, Ayyalusamy; Nishiyama, Yusuke

    2016-01-01

    Chemical shift anisotropy (CSA) tensors offer a wealth of information for structural and dynamics studies of a variety of chemical and biological systems. In particular, CSA of amide protons can provide piercing insights into hydrogen-bonding interactions that vary with the backbone conformation of a protein and dynamics. However, the narrow span of amide proton resonances makes it very difficult to measure (1)H CSAs of proteins even by using the recently proposed 2D (1)H/(1)H anisotropic/isotropic chemical shift (CSA/CS) correlation technique. Such difficulties due to overlapping proton resonances can in general be overcome by utilizing the broad span of isotropic chemical shifts of low-gamma nuclei like (15)N. In this context, we demonstrate a proton-detected 3D (15)N/(1)H/(1)H CS/CSA/CS correlation experiment at fast MAS frequency (70kHz) to measure (1)H CSA values of unresolved amide protons of N-acetyl-(15)N-l-valyl-(15)N-l-leucine (NAVL).

  10. Vicinal 1H-1H NMR coupling constants from density functional theory as reliable tools for stereochemical analysis of highly flexible multichiral center molecules.

    PubMed

    López-Vallejo, Fabian; Fragoso-Serrano, Mabel; Suárez-Ortiz, Gloria Alejandra; Hernández-Rojas, Adriana C; Cerda-García-Rojas, Carlos M; Pereda-Miranda, Rogelio

    2011-08-05

    A protocol for stereochemical analysis, based on the systematic comparison between theoretical and experimental vicinal (1)H-(1)H NMR coupling constants, was developed and applied to a series of flexible compounds (1-8) derived from the 6-heptenyl-5,6-dihydro-2H-pyran-2-one framework. The method included a broad conformational search, followed by geometry optimization at the DFT B3LYP/DGDZVP level, calculation of the vibrational frequencies, thermochemical parameters, magnetic shielding tensors, and the total NMR spin-spin coupling constants. Three scaling factors, depending on the carbon atom hybridizations, were found for the (1)H-C-C-(1)H vicinal coupling constants: f((sp3)-(sp3)) = 0.910, f((sp3)-(sp2)) = 0.929, and f((sp2)-(sp2))= 0.977. A remarkable correlation between the theoretical (J(pre)) and experimental (1)H-(1)H NMR (J(exp)) coupling constants for spicigerolide (1), a cytotoxic natural product, and some of its synthetic stereoisomers (2-4) demonstrated the predictive value of this approach for the stereochemical assignment of highly flexible compounds containing multiple chiral centers. The stereochemistry of two natural 6-heptenyl-5,6-dihydro-2H-pyran-2-ones (14 and 15) containing diverse functional groups in the heptenyl side chain was also analyzed by application of this combined theoretical and experimental approach, confirming its reliability. Additionally, a geometrical analysis for the conformations of 1-8 revealed that weak hydrogen bonds substantially guide the conformational behavior of the tetraacyloxy-6-heptenyl-2H-pyran-2-ones.

  11. Selective excitation enables assignment of proton resonances and (1)H-(1)H distance measurement in ultrafast magic angle spinning solid state NMR spectroscopy.

    PubMed

    Zhang, Rongchun; Ramamoorthy, Ayyalusamy

    2015-07-21

    Remarkable developments in ultrafast magic angle spinning (MAS) solid-state NMR spectroscopy enabled proton-based high-resolution multidimensional experiments on solids. To fully utilize the benefits rendered by proton-based ultrafast MAS experiments, assignment of (1)H resonances becomes absolutely necessary. Herein, we propose an approach to identify different proton peaks by using dipolar-coupled heteronuclei such as (13)C or (15)N. In this method, after the initial preparation of proton magnetization and cross-polarization to (13)C nuclei, transverse magnetization of desired (13)C nuclei is selectively prepared by using DANTE (Delays Alternating with Nutations for Tailored Excitation) sequence and then, it is transferred to bonded protons with a short-contact-time cross polarization. Our experimental results demonstrate that protons bonded to specific (13)C atoms can be identified and overlapping proton peaks can also be assigned. In contrast to the regular 2D HETCOR experiment, only a few 1D experiments are required for the complete assignment of peaks in the proton spectrum. Furthermore, the finite-pulse radio frequency driven recoupling sequence could be incorporated right after the selection of specific proton signals to monitor the intensity buildup for other proton signals. This enables the extraction of (1)H-(1)H distances between different pairs of protons. Therefore, we believe that the proposed method will greatly aid in fast assignment of peaks in proton spectra and will be useful in the development of proton-based multi-dimensional solid-state NMR experiments to study atomic-level resolution structure and dynamics of solids.

  12. Structural, electronic and vibrational properties of N,N'-1H,1H-perfluorobutyl dicyanoperylenecarboxydiimide (PDI-FCN2) crystal.

    PubMed

    Colle, Renato; Grosso, Giuseppe; Cassinese, Antonio; Centore, Roberto

    2013-09-21

    We present a theoretical and experimental investigation of the crystalline structure of N,N'-1H,1H-perfluorobutyl dicyanoperylenecarboxydiimide (PDI-FCN2) that has been deduced combining experimental XRD data, obtained from powders, with global-optimization algorithms which allow to identify Bravais lattice, primitive cell parameters, and space group of the crystal. The XRD spectrum calculated for the proposed crystalline structure very well reproduces the measured XRD data. Our results suggest the triclinic lattice structure of spatial groups P1 and P1, respectively, for the crystalline PDI-FCN2-1,7 and PDI-FCN2-1,6 isomers. In both cases, the primitive cell contains a single molecule. On the proposed crystalline structures, KS-DFT cell energy calculations, including van der Waals interactions, have been performed to assign the minimum energy geometrical structure and orientation of the molecule inside the corresponding primitive cell. These calculations evidence the molecular packing that characterizes the strong anisotropy of the PDI-FCN2 crystal. Electronic band-structures calculated for both isomers within the Kohn-Sham density-functional theory indicate that the crystalline P1 structure is an indirect gap semiconductor, while the P1 structure is a direct gap semiconductor. The electronic band structure calculations on the optimized crystal geometries highlight strong anisotropy in the dispersion curves E(k), which roots at the molecular packing in the crystal. Finally, the vibrational spectrum of both crystalline isomers has been calculated in the harmonic approximation and the dominant vibrational frequencies have been associated to collective motions of selected atoms in the molecules.

  13. Selective excitation enables assignment of proton resonances and 1H-1H distance measurement in ultrafast magic angle spinning solid state NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhang, Rongchun; Ramamoorthy, Ayyalusamy

    2015-07-01

    Remarkable developments in ultrafast magic angle spinning (MAS) solid-state NMR spectroscopy enabled proton-based high-resolution multidimensional experiments on solids. To fully utilize the benefits rendered by proton-based ultrafast MAS experiments, assignment of 1H resonances becomes absolutely necessary. Herein, we propose an approach to identify different proton peaks by using dipolar-coupled heteronuclei such as 13C or 15N. In this method, after the initial preparation of proton magnetization and cross-polarization to 13C nuclei, transverse magnetization of desired 13C nuclei is selectively prepared by using DANTE (Delays Alternating with Nutations for Tailored Excitation) sequence and then, it is transferred to bonded protons with a short-contact-time cross polarization. Our experimental results demonstrate that protons bonded to specific 13C atoms can be identified and overlapping proton peaks can also be assigned. In contrast to the regular 2D HETCOR experiment, only a few 1D experiments are required for the complete assignment of peaks in the proton spectrum. Furthermore, the finite-pulse radio frequency driven recoupling sequence could be incorporated right after the selection of specific proton signals to monitor the intensity buildup for other proton signals. This enables the extraction of 1H-1H distances between different pairs of protons. Therefore, we believe that the proposed method will greatly aid in fast assignment of peaks in proton spectra and will be useful in the development of proton-based multi-dimensional solid-state NMR experiments to study atomic-level resolution structure and dynamics of solids.

  14. Structural, electronic and vibrational properties of N,N'-1H,1H-perfluorobutyl dicyanoperylenecarboxydiimide (PDI-FCN2) crystal

    NASA Astrophysics Data System (ADS)

    Colle, Renato; Grosso, Giuseppe; Cassinese, Antonio; Centore, Roberto

    2013-09-01

    We present a theoretical and experimental investigation of the crystalline structure of N,N'-1H,1H-perfluorobutyl dicyanoperylenecarboxydiimide (PDI-FCN2) that has been deduced combining experimental XRD data, obtained from powders, with global-optimization algorithms which allow to identify Bravais lattice, primitive cell parameters, and space group of the crystal. The XRD spectrum calculated for the proposed crystalline structure very well reproduces the measured XRD data. Our results suggest the triclinic lattice structure of spatial groups Poverline{1} and P1, respectively, for the crystalline PDI-FCN2-1,7 and PDI-FCN2-1,6 isomers. In both cases, the primitive cell contains a single molecule. On the proposed crystalline structures, KS-DFT cell energy calculations, including van der Waals interactions, have been performed to assign the minimum energy geometrical structure and orientation of the molecule inside the corresponding primitive cell. These calculations evidence the molecular packing that characterizes the strong anisotropy of the PDI-FCN2 crystal. Electronic band-structures calculated for both isomers within the Kohn-Sham density-functional theory indicate that the crystalline Poverline{1} structure is an indirect gap semiconductor, while the P1 structure is a direct gap semiconductor. The electronic band structure calculations on the optimized crystal geometries highlight strong anisotropy in the dispersion curves E(k), which roots at the molecular packing in the crystal. Finally, the vibrational spectrum of both crystalline isomers has been calculated in the harmonic approximation and the dominant vibrational frequencies have been associated to collective motions of selected atoms in the molecules.

  15. Improved HMQC-Type and HSQC-Type 1D Spectra Using Pulsed Field Gradients

    NASA Astrophysics Data System (ADS)

    Parella, T.; Sanchezferrando, F.; Virgili, A.

    A family of 1D methods are described using a combination of HSQC-type (or HMQC-type) heteronuclear preparation blocks with homonuclear transfer schemes, such as COSY, n-step RELAY, TOCSY, ROESY, and NOESY, in order to reveal direct or long-range heteronuclear connectivities, as well as relayed (scalar or dipolar) interproton connectivities. Two essential features of this approach are: (i) selective carbon excitation simultaneous with a proton spin-lock period, to avoid dephasing during the selective carbon pulse length; and (ii) coherence selection by pulsed field gradients of the desired coherences, to improve time performance and get cleaner spectra devoid of artifacts usually produced by imperfect subtraction when using phase-cycling methods. The resulting high-quality 1D spectra allow the easy extraction of accurate values for the relevant homo- and heteronuclear coupling constants. This approach is particularly useful when strongly overlapped proton systems prevent the application of conventional 1D experiments based on proton-selective excitation. Results are presented for sucrose.

  16. Population transfer HMQC for half-integer quadrupolar nuclei

    SciTech Connect

    Wang, Qiang; Xu, Jun; Feng, Ningdong; Deng, Feng E-mail: jean-paul.amoureux@univ-lille1.fr; Li, Yixuan; Trébosc, Julien; Lafon, Olivier; Hu, Bingwen; Chen, Qun; Amoureux, Jean-Paul E-mail: jean-paul.amoureux@univ-lille1.fr

    2015-03-07

    This work presents a detailed analysis of a recently proposed nuclear magnetic resonance method [Wang et al., Chem. Commun. 49(59), 6653-6655 (2013)] for accelerating heteronuclear coherence transfers involving half-integer spin quadrupolar nuclei by manipulating their satellite transitions. This method, called Population Transfer Heteronuclear Multiple Quantum Correlation (PT-HMQC), is investigated in details by combining theoretical analyses, numerical simulations, and experimental investigations. We find that compared to instant inversion or instant saturation, continuous saturation is the most practical strategy to accelerate coherence transfers on half-integer quadrupolar nuclei. We further demonstrate that this strategy is efficient to enhance the sensitivity of J-mediated heteronuclear correlation experiments between two half-integer quadrupolar isotopes (e.g., {sup 27}Al-{sup 17}O). In this case, the build-up is strongly affected by relaxation for small T{sub 2}′ and J coupling values, and shortening the mixing time makes a huge signal enhancement. Moreover, this concept of population transfer can also be applied to dipolar-mediated HMQC experiments. Indeed, on the AlPO{sub 4}-14 sample, one still observes experimentally a 2-fold shortening of the optimum mixing time albeit with no significant signal gain in the {sup 31}P-({sup 27}Al) experiments.

  17. Deuteron polarimetry at COSY

    SciTech Connect

    Chiladze, D.; Grigoriev, K.; Kacharava, A.; Rathmann, F.; Stroeher, H.; Wilkin, C.

    2007-06-13

    The vector Pz and tensor Pzz polarizations of a deuteron beam have been measured using elastic deuteron-carbon scattering at 75.6 MeV and deuteron-proton scattering at 270 MeV. After acceleration to 1170 MeV inside the COSY storage ring, the polarizations of the deuterons were remeasured by studying the analyzing powers of a variety of nuclear reactions at the ANKE magnetic spetrometer. The overall precisions obtained were about 4% for both Pz and Pzz. One of the motivation for the experimental programme is the direct reconstruction of the spin-dependent amplitudes, including relative phases, of large angle neutron-proton elastic scattering, through the study of the p(d,2p)n charge-exchange reaction up to the highest available deuteron energy at COSY (2.3 GeV)

  18. Physics at CELSIUS and COSY

    SciTech Connect

    Machner, H.

    2006-02-11

    We review some selected experimental results achieved at the synchrotrons CELSIUS in Sweden and COSY in Germany. They concentrate on meson production with emphasis on the underlying quark structure. The project WASA at COSY is discussed and the search for symmetry breaking in decays of {eta} and {eta}' mesons is highlighted.

  19. 3D 15N/15N/1H chemical shift correlation experiment utilizing an RFDR-based 1H/1H mixing period at 100 kHz MAS

    NASA Astrophysics Data System (ADS)

    Nishiyama, Yusuke; Malon, Michal; Ishii, Yuji; Ramamoorthy, Ayyalusamy

    2014-07-01

    Homonuclear correlation NMR experiments are commonly used in the high-resolution structural studies of proteins. While 13C/13C chemical shift correlation experiments utilizing dipolar recoupling techniques are fully utilized under MAS, correlation of the chemical shifts of 15N nuclei in proteins has been a challenge. Previous studies have shown that the negligible 15N-15N dipolar coupling in peptides or proteins necessitates the use of a very long mixing time (typically several seconds) for effective spin diffusion to occur and considerably slows down a 15N/15N correlation experiment. In this study, we show that the use of mixing proton magnetization, instead of 15N, via the recoupled 1H-1H dipolar couplings enable faster 15N/15N correlation. In addition, the use of proton-detection under ultrafast MAS overcomes the sensitivity loss due to multiple magnetization transfer (between 1H and 15N nuclei) steps. In fact, less than 300 nL (∼1.1 micromole quantity) sample is sufficient to acquire the 3D spectrum within 5 h. Our results also demonstrate that a 3D 15N/15N/1H experiment can render higher resolution spectra that will be useful in the structural studies of proteins at ultrafast MAS frequencies. 3D 15N/15N/1H and 2D radio frequency-driven dipolar recoupling (RFDR)-based 1H/1H experimental results obtained from a powder sample of N-acetyla-L-15N-valyl-L-15N-leucine at 70 and 100 kHz MAS frequencies are presented.

  20. 1H,1H,5H-Perfluoropentyl-1,1,2,2-tetrafluoroethylether as a co-solvent for high voltage LiNi1/3Co1/3Mn1/3O2/graphite cells

    NASA Astrophysics Data System (ADS)

    Wang, Chengyun; Zuo, Xiaoxi; Zhao, Minkai; Xiao, Xin; Yu, Le; Nan, Junmin

    2016-03-01

    1H,1H,5H-Perfluoropentyl-1,1,2,2-tetrafluoroethylether (F-EAE) mixed with ethylene carbonate (EC), diethyl carbonate (DEC), and lithium hexafluorophosphate (LiPF6) is evaluated as a co-solvent high-potential electrolyte of LiNi1/3Co1/3Mn1/3O2/graphite batteries. Linear sweep voltammetry (LSV) and cyclic voltammetry (CV) indicate that the EC/DEC-based electrolyte with F-EAE possesses a high oxidation potential (>5.2 V vs. Li/Li+) and excellent film-forming characteristics. With 40 wt% F-EAE in the electrolyte, the capacity retention of the LiNi1/3Co1/3Mn1/3O2/graphite pouch cells that are cycled between 3.0 and 4.5 V is significantly improved from 28.8% to 86.8% after 100 cycles. In addition, electrochemical impedance spectroscopy (EIS) of three-electrode pouch cells, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) are used to characterize the effects of F-EAE on the enhanced capacity retention. It is demonstrated that F-EAE facilitates the formation of a stable surface electrolyte interface (SEI) layer with low impedance on the anode and effectively suppresses an increase in the charge-transfer resistance on the cathode. These results suggest that F-EAE can serve as an alternative electrolyte solvent for 4.5 V high voltage rechargeable lithium-ion batteries.

  1. Physics at COSY-Juelich

    SciTech Connect

    Stroeher, Hans

    2011-10-21

    COSY, a storage and cooler synchrotron, which is fed by an injector cyclotron, is operated at Forschungszentrum Juelich (Germany). It provides phase space cooled polarized or unpolarized beams of protons and deuterons with momenta between 0.3 and 3.7 GeV/c for internal experiments and to external target stations. The major experimental facilities, used for the ongoing physics program, are ANKE and WASA (internal) and TOF (external). A new internal target station to investigate polarization build-up by spin-filtering (PAX) has recently been commissioned. COSY is the machine for hadron spin physics on a world-wide scale, which is also used for tests in conjunction with plans to build a dedicated storage ring for electric dipole moment (EDM) measurements of proton, deuteron and {sup 3}He. In this contribution recent results as well as future plans are summarized.

  2. N*ews from COSY

    NASA Astrophysics Data System (ADS)

    Ströher, Hans

    2012-04-01

    COSY, a storage and cooler synchrotron, which is fed by an injector cyclotron, is operated at Forschungszentrum Jülich (Germany). It provides phase space cooled polarized or unpolarized beams of protons and deuterons with momenta between 0.3 and 3.7 GeV/c for internal experiments and to external target stations. The major experimental facilities, used for the ongoing physics program, are ANKE and WASA (internal) and TOF (external). A new internal target station to investigate polarization build-up by spin-filtering (PAX) has recently been commissioned. COSY is the machine for hadron spin physics on a world-wide scale, which in recent times is also used for tests in conjunction with plans to build a dedicated storage ring for electric dipole moment (EDM) measurements of proton, deuteron and 3He. In this contribution selected experimental results from the N*-program are presented.

  3. Spin-filtering at COSY

    NASA Astrophysics Data System (ADS)

    Weidemann, Christian; PAX Collaboration

    2011-05-01

    The Spin Filtering experiments at COSY and AD at CERN within the framework of the Polarized Antiproton EXperiments (PAX) are proposed to determine the spin-dependent cross sections in bar pp scattering by observation of the buildup of polarization of an initially unpolarized stored antiproton beam after multiple passage through an internal polarized gas target. In order to commission the experimental setup for the AD and to understand the relevant machine parameters spin-filtering will first be done with protons at COSY. A first major step toward this goal has been achieved with the installation of the required mini-β section in summer 2009 and it's commissioning in January 2010. The target chamber together with the atomic beam source and the so-called Breit-Rabi polarimeter have been installed and commissioned in summer 2010. In addition an openable storage cell has been used. It provides a target thickness of 5·1013 atoms/cm2. We report on the status of spin-filtering experiments at COSY and the outcome of a recent beam time including studies on beam lifetime limitations like intra-beam scattering and the electron-cooling performance as well as machine acceptance studies.

  4. Recent Results from Experiments at COSY

    SciTech Connect

    Goldenbaum, Frank

    2010-08-05

    In hadron physics, experiments using hadronic probes may shed light on open questions on the structure of hadrons, their interactions that are subject to the strong force and on the symmetries of nature. Therefore a major focus of the physics program studied at the COoler SYnchrotron COSY of the Forschungszentrum Juelich is the production of mesons and hyperons in hadron- hadron scattering with the aim to investigate relevant production processes, interactions of the participating particles as well as symmetries and symmetry breaking. The COoler SYnchrotron COSY at Juelich accelerates protons and deuterons with momenta up to 3.7 GeV/c covering hadron physics in the light quark sector. The availability of the beam cooling systems allow precision measurements, using polarized proton and deuteron beams in combination with polarized Hydrogen or Deuterium targets. Due to the excellent experimental conditions at COSY single- and double-polarization measurements can be performed with high reaction rates. With the operation of the recently installed WASA-at-COSY apparatus, high-statistics studies aiming at rare decays of {eta} and {eta}{sup '} are effectively turning COSY into a meson factory. This contribution summarizes the ongoing physics program at the COSY facility, using the detector systems ANKE, WASA and COSY-TOF highlighting a few selective recent results and outlining future developments. The research at COSY also provides a step towards the realization of FAIR with studies on spin manipulation and polarization build-up of protons in polarized targets.

  5. Elucidation of the structures of residual and dissolved pine kraft lignins using an HMQC NMR technique.

    PubMed

    Balakshin, Mikhail Yu; Capanema, Ewellyn A; Chen, Chen-Loung; Gracz, Hanna S

    2003-10-08

    Comparative studies on the structures of residual and dissolved lignins isolated from pine kraft pulp and pulping liquor have been undertaken using the (1)H-(13)C HMQC NMR technique, GPC, and sugar analysis to elucidate the reaction mechanisms in kraft pulping and the lignin reactivity. A modified procedure for the isolation of enzymatic residual lignins has resulted in an appreciable decrease in protein contaminants in the residual lignin preparations (N content < 0.2%). The very high dispersion of HMQC spectra allows identification of different lignin moieties, which signals appear overlapped in 1D (13)C NMR spectra. Elucidation of the role of condensation reactions indicates that an increase in the degree of lignin condensation during pulping results from accumulation of original condensed lignin moieties rather than from the formation of new alkyl-aryl structures. Among aryl-vinyl type moieties, only stilbene structures are accumulated in lignin in appreciable amounts. Benzyl ether lignin-carbohydrate bonds involving primary hydroxyl groups of carbohydrates have been detected in residual and dissolved lignin preparations. Structures of the alpha-hydroxyacid type have been postulated to be among the important lignin degradation products in kraft pulping. The effect of the isolation method on the lignin structure and differences between the residual and dissolved lignins are discussed.

  6. Acylated pregnane glycosides from Caralluma russeliana.

    PubMed

    Abdel-Sattar, Essam; Ahmed, Ahmed A; Hegazy, Mohamed-Elamir F; Farag, Mohamed A; Al-Yahya, Mohammad Abdul-Aziz

    2007-05-01

    The chloroform extract of the aerial parts of Caralluma russeliana yielded four acylated pregnane glycosides, namely russeliosides E-H, three were found now. The structures of the compounds were elucidated using MS, 1H NMR, 13C NMR, 1H-1H COSY, HMQC, NOESY and HMBC experiments.

  7. Highly oxygenated monoterpenes from Chenopodium ambrosioides.

    PubMed

    Ahmed, A A

    2000-07-01

    Three new monoterpenes (3-5) were isolated from an organic extract of the aerial parts of Chenopodium ambrosioides. Structures were established on the basis of MS and NMR spectroscopic ((1)H, (13)C, (1)H-(1)H COSY, HMQC and HMBC) data.

  8. Unequivocal assignments of flavonoids from Tephrosia sp. (Fabaceae).

    PubMed

    Arriaga, A M C; Lima, J Q; Vasconcelos, J N; de Oliveira, M C F; Andrade-Neto, M; Santiago, G M P; Uchoa, D E A; Malcher, G T; Mafezoli, J; Braz-Filho, R

    2009-06-01

    (1)H and (13)C NMR chemical shifts of praecansone B, pongaflavone and dehydrorotenone isolated from Tephrosia egregia Sandw and obovatin from T. toxicaria Pers. were unambiguously assigned by 1D and 2D NMR experiments including (1)H, (1)H COSY, gHMQC and gHMBC, allowing the correction of literature assignments.

  9. Test of Time Reversal Invariance and COSY

    NASA Astrophysics Data System (ADS)

    Eversheim, Dieter; Lorentz, Bernd; Valdau, Yury; PAX Collaboration

    2013-07-01

    Test of Time Reversal Invariance in pd scattering is planned at the COoler-SYnchrotron COSY-Jülich using the PAX internal target station. Feasibility test, performed in September 2012, have shown possibility to perform such an experiment using COSY and PAX. In parallel to the PAX upgrade a new high precision beam current measurement system will be constructed by the end of 2014. After these modifications, it will be possible to improve the current upper limit on a strength of T-odd P-even NN potential by an order of magnitude.

  10. Making Submicron CoSi2 Structures On Silicon Substrates

    NASA Technical Reports Server (NTRS)

    Nieh, Simon K. W.; Lin, True-Lon; Fathauer, Robert W.

    1989-01-01

    Experimetnal fabrication process makes submicron-sized structures of single-crystal metallic CoSi2 on silicon substrates. Amorphous Co:Si(1:2) crystallized by electron beam becoming single-crystal CoSi2. Remaining amorphous Co:Si then preferentially etched away. When fully developed, process used to make fine wires or dots exhibiting quantum confinement of charge carriers.

  11. Probing hydrogen bonding in cocrystals and amorphous dispersions using (14)N-(1)H HMQC solid-state NMR.

    PubMed

    Tatton, Andrew S; Pham, Tran N; Vogt, Frederick G; Iuga, Dinu; Edwards, Andrew J; Brown, Steven P

    2013-03-04

    Cocrystals and amorphous solid dispersions have generated interest in the pharmaceutical industry as an alternative to more established solid delivery forms. The identification of intermolecular hydrogen bonding interactions in a nicotinamide palmitic acid cocrystal and a 50% w/w acetaminophen-polyvinylpyrrolidone solid dispersion are reported using advanced solid-state magic-angle spinning (MAS) NMR methods. The application of a novel (14)N-(1)H HMQC experiment, where coherence transfer is achieved via through-space couplings, is shown to identify specific hydrogen bonding motifs. Additionally, (1)H isotropic chemical shifts and (14)N electric field gradient (EFG) parameters, both accessible from (14)N-(1)H HMQC experiments, are shown to be sensitive to changes in hydrogen bonding geometry. Numerous indicators of molecular association are accessible from this experiment, including NH cross-peaks occurring from intermolecular hydrogen bonds and changes in proton chemical shifts or electric field gradient parameters. First-principles calculations using the GIPAW approach that yield accurate estimates of isotropic chemical shifts, and EFG parameters were used to assist in assignment. It is envisaged that (14)N-(1)H HMQC solid state NMR experiments could become a valuable screening technique of solid delivery forms in the pharmaceutical industry.

  12. Electrostatic potential map modelling with COSY Infinity

    NASA Astrophysics Data System (ADS)

    Maloney, J. A.; Baartman, R.; Planche, T.; Saminathan, S.

    2016-06-01

    COSY Infinity (Makino and Berz, 2005) is a differential-algebra based simulation code which allows accurate calculation of transfer maps to arbitrary order. COSY's existing internal procedures were modified to allow electrostatic elements to be specified using an array of field potential data from the midplane. Additionally, a new procedure was created allowing electrostatic elements and their fringe fields to be specified by an analytic function. This allows greater flexibility in accurately modelling electrostatic elements and their fringe fields. Applied examples of these new procedures are presented including the modelling of a shunted electrostatic multipole designed with OPERA, a spherical electrostatic bender, and the effects of different shaped apertures in an electrostatic beam line.

  13. The physics program of PAX at COSY

    NASA Astrophysics Data System (ADS)

    Valdau, Yury; Aksentyev, Alexander; Eversheim, Dieter; Lorentz, Bernd

    2016-02-01

    The construction of the PAX installation was inspired by the idea to make a beam of polarized antiprotons available for the experiments at the HESR FAIR. A spin filtering experiment with transversally polarized protons was realized using the new PAX installation at COSY. The results of this measurement are in perfect agreement with the FILTEX experiment. Hence, filtering is a viable method to produce a stored beam of polarized antiprotons. Another experiment which can be pursued using the PAX installation is the test of Time Reversal Invariance at COSY (TRIC). The goal of the TRIC experiment is to improve the present upper limit on violation of the T-odd P-even interaction by an order of magnitude using a genuine null observable available in a double polarized pd scattering. The status of the PAX spin filtering experiments as well as present understanding of the possible systematic uncertainties in TRIC are presented in this contribution.

  14. Physics at COSY-Jülich

    NASA Astrophysics Data System (ADS)

    Ströher, Hans

    2011-10-01

    COSY, a storage and cooler synchrotron, which is fed by an injector cyclotron, is operated at Forschungszentrum Jülich (Germany). It provides phase space cooled polarized or unpolarized beams of protons and deuterons with momenta between 0.3 and 3.7 GeV/c for internal experiments and to external target stations. The major experimental facilities, used for the ongoing physics program, are ANKE and WASA (internal) and TOF (external). A new internal target station to investigate polarization build-up by spin-filtering (PAX) has recently been commissioned. COSY is the machine for hadron spin physics on a world-wide scale, which is also used for tests in conjunction with plans to build a dedicated storage ring for electric dipole moment (EDM) measurements of proton, deuteron and 3He. In this contribution recent results as well as future plans are summarized.

  15. COSY-11: How will we remember it ?

    SciTech Connect

    Wilkin, Colin

    2007-11-07

    A personal selection is made of the highlights of the COSY-11 physics program undertaken at the COoler SYnchrotron of the Forschungszentrum Juelich. This has been particularly rich in the field of strange and non-strange meson production in proton-proton and proton-deuteron collisions. The results are considered in relation to experiments carried out at other facilities and with respect to their impact on theory.

  16. Rapid acquisition of wideline MAS solid-state NMR spectra with fast MAS, proton detection, and dipolar HMQC pulse sequences.

    PubMed

    Rossini, Aaron J; Hanrahan, Michael P; Thuo, Martin

    2016-09-14

    The solid-state NMR spectra of many NMR active elements are often extremely broad due to the presence of chemical shift anisotropy (CSA) and/or the quadrupolar interaction (for nuclei with spin I > 1/2). These NMR interactions often give rise to wideline solid-state NMR spectra which can span hundreds of kHz or several MHz. Here we demonstrate that by using fast MAS, proton detection and dipolar hetero-nuclear multiple-quantum (D-HMQC) pulse sequences, it is possible to rapidly acquire 2D spectra which correlate (1)H chemical shifts to the indirectly detected wideline MAS powder patterns of dipolar coupled hetero-nuclei. The D-HMQC pulse sequence enables broadband excitation of the wideline hetero-nuclear NMR spectrum and provides higher sensitivity by detecting the narrower and more sensitive (1)H NMR signal. This approach is demonstrated for the rapid acquisition of 2D (1)H detected (195)Pt solid-state NMR spectra of cisplatin and transplatin and the (71)Ga solid-state NMR spectrum of a self-assembled Ga coordination polymer of unconfirmed structure. This approach should be broadly applicable for the rapid acquisition of wideline MAS solid-state NMR spectra of moderately abundant NMR nuclei.

  17. Meson-production experiments at COSY-Jülich

    NASA Astrophysics Data System (ADS)

    Büscher, M.

    2010-09-01

    Selected results from experiments at COSY-Jülich are presented: an attempt to measure the mass of the η meson with high precision (ANKE facility), first steps towards the detection of rare η decays (WASA), and several measurements of Kbar K-pair production (ANKE, COSY-11, MOMO).

  18. Making CoSi(2) Layers By Ion Implantation

    NASA Technical Reports Server (NTRS)

    Namavar, Fereydoon

    1994-01-01

    Monolithic photovoltaic batteries containing vertical cells include buried CoSi(2) contact layers. Vertical-junction photovoltaic cells in series fabricated in monolithic structure. N- and p-doped silicon layers deposited epitaxially. The CoSi(2) layers, formed by ion implantation and annealing, serve as thin, low-resistance ohmic contacts between cells.

  19. Spin Filtering Studies at COSY and AD

    NASA Astrophysics Data System (ADS)

    Nass, Alexander

    2009-08-01

    The high physics potential of experiments with stored high-energy polarized antiprotons led to the proposal of PAX (Polarized Antiproton eXperiment) [1] for the High Energy Storage Ring (HESR) of the FAIR at GSI (Darmstadt/Germany). It is proposed to polarize a stored antiproton beam by means of spin filtering with a polarized H (D) gas target. The feasibility of spin filtering has been demonstrated in the FILTEX experiment. The current interpretation foresees a self-cancellation of the electron contribution to the filtering process and only the hadronic contribution is effective. Several experimental studies with protons (at COSY/Jülich) as well as antiprotons (at AD/CERN) will be carried out to test the principle and measure p¯p⃗ and p¯d⃗ cross sections. A polarized internal gas target (PIT) with surrounding Silicon detectors immersed into a low-β section has to be set up.

  20. Two compounds from Peucedanum dissolutum.

    PubMed

    Wu, Xian-Li; Li, Yi; Kong, Ling-Yi; Min, Zhi-Da

    2004-12-01

    A new compound, 3'(R)-O-beta-D-glucopyranosyl-3',4'-dihydroxanthyletin (1), and a known compound, prim-O-glucosylcimifugin (2), were isolated from the roots of Peucedanum dissolutum. The structure of 1 was elucidated by spectral evidence and chemical reaction. The NMR signals of carbons and protons of 2 were assigned for the first time by analysis of (1)H-(1)H COSY, HMQC and HMBC spectra.

  1. Two new pentacyclic triterpenoids from Lantana camara LINN.

    PubMed

    Begum, Sabira; Zehra, Syeda Qamar; Siddiqui, Bina Shaheen

    2008-09-01

    Two new pentacyclic triterpenoids, namely lantanoic acid (1) and camaranoic acid (2), and six known compounds such as lantic acid, camarinic acid, camangeloyl acid, camarinin, oleanonic acid, and ursonic acid were isolated from the aerial parts of Lantana camara LINN. Structures of the new constituents were elucidated by chemical transformation and spectral studies including 1D ((1)H- and (13)C-NMR) and 2D ((1)H-(1)H correlation spectroscopy (COSY), nuclear Overhauser effect spectroscopy (NOESY), (1)H-(1)H total correlation spectroscopy (TOCSY), J-resolved, (1)H-detected heteronuclear multiple quantum coherence (HMQC), and heteronuclear multiple bond connectivity (HMBC)) NMR spectroscopy.

  2. COSI: The Compton Spectrometer and Imager Science Program

    NASA Astrophysics Data System (ADS)

    Tomsick, John; Jean, Pierre; Chang, Hsiang-Kuang; Boggs, Steven; Zoglauer, A.; Von Ballmoos, Peter; Amman, Mark; Chiu, Jeng-Lun; Chang, Yuan-Hann.; Chou, Yi; Kierans, Carolyn; Lin, Chih-Hsun.; Lowell, Alex; Shang, Jie-Rou.; Tseng, Chao-Hsiung; Yang, Chien-Ying

    The Compton Spectrometer and Imager (COSI), which was formerly known as the Nuclear Compton Telescope (NCT), is a balloon-borne soft gamma-ray telescope (0.2-5 MeV) designed to probe the origins of Galactic positrons, uncover sites of nucleosynthesis in the Galaxy, and perform pioneering studies of gamma-ray polarization in a number of source classes. COSI uses a compact Compton telescope design, resulting from a decade of development under NASA's ROSES program - a modern take on techniques successfully pioneered by COMPTEL on CGRO. We have rebuilt the COSI instrument and flight systems, upgraded for balloon flights and improved polarization sensitivity. We will present the redesign of COSI and the overall goals of the 5-year science program. Three science flights are planned to fulfill the COSI science goals: an LDB in 2014 from Antarctica on a superpressure balloon (SuperCOSI), followed by two 100-day ULDB flights from New Zealand. COSI is a wide-field survey telescope designed to perform imaging, spectroscopy, and polarization measurements. It employs a novel Compton telescope design utilizing a compact array of cross-strip germanium detectors (GeDs) to resolve individual gamma-ray interactions with high spectral and spatial resolution. The COSI array is housed in a common vacuum cryostat cooled by a mechanical cryocooler. An active CsI shield encloses the cryostat on the sides and bottom. The FoV of the instrument covers 25% of the full sky at a given moment. The COSI instrument is mature, building upon considerable heritage from the previous NCT balloon instrument that underwent a successful technology demonstration flight in June 2005 from Fort Sumner, NM, a successful "first light" science flight from Fort Sumner in May 2009, and quickly turned around and delivered on time for a launch campaign from Alice Springs, Australia in June 2010, where it unfortunately suffered a launch mishap. The NCT instrument and Flight System are being rebuilt under the NASA

  3. CLIP-COSY: A Clean In-Phase Experiment for the Rapid Acquisition of COSY-type Correlations.

    PubMed

    Koos, Martin R M; Kummerlöwe, Grit; Kaltschnee, Lukas; Thiele, Christina M; Luy, Burkhard

    2016-06-27

    The COSY experiment is an essential homonuclear 2D NMR experiment for the assignment of resonances. Its multiplet line shape, however, is often overly complicated, potentially leads to signal intensity losses, and is responsible for long minimum overall acquisition times. Herein, we present CLIP-COSY, a COSY-type experiment yielding clean in-phase peaks. It can be recorded within a few minutes and benefits from enhanced signal intensities for most cross-peaks. In combination with non-uniform sampling, the experiment times can be further reduced, and the in-phase multiplets enable the application of modern homonuclear decoupling techniques in both dimensions. As antiphase cancelations are avoided, CLIP-COSY can also be applied to macromolecules and other samples with broadened lines.

  4. The Compton Spectrometer and Imager (COSI) Superpressure Balloon Payload

    NASA Astrophysics Data System (ADS)

    Boggs, Steven E.

    2014-08-01

    The Compton Spectrometer and Image (COSI) is a ULDB-borne soft gamma-ray telescope (0.2-5 MeV) designed to probe the origins of Galactic positrons, uncover sites of nucleosynthesis in the Galaxy, and perform pioneering studies of gamma-ray polarization in a number of source classes. COSI uses a compact Compton telescope design, resulting from a decade of development under NASA’s ROSES program - a modern take on techniques successfully pioneered by COMPTEL on CGRO. COSI performs groundbreaking science by combining improvements in sensitivity, spectral resolution, and sky coverage. The COSI instrument and flight systems have been designed for flight on NASA’s 18 MCF superpressure balloon (SPB). We are now beginning a series science flights to fulfill the COSI science goals: a SPB in 2014 from Antarctica, followed by two 100-day ULDB flights from New Zealand.COSI is a wide-field survey telescope designed to perform imaging, spectroscopy, and polarization measurements. It employs a novel Compton telescope design utilizing a compact array of cross-strip germanium detectors (GeDs) to resolve individual gamma-ray interactions with high spectral and spatial resolution. The COSI array is housed in a common vacuum cryostat cooled by a mechanical cryocooler. An active CsI Shield encloses the cryostat on the sides and bottom. The FoV of the instrument covers 25% of the full sky at a given moment.The COSI instrument builds upon considerable heritage from the previous Nuclear Compton Telescope (NCT) balloon instrument that underwent a successful technology demonstration flight in June 2005 from Fort Sumner, NM, a successful “first light” science flight from Fort Sumner in May 2009, and a launch campaign from Alice Springs, Australia in June 2010, where it unfortunately suffered a launch mishap. COSI has been upgraded from the previous NCT instrument by conversion to a detector configuration optimized for polarization sensitivity and addition of a cryocooler to remove

  5. EPIC Muon Cooling Simulations using COSY INFINITY

    SciTech Connect

    J.A. Maloney, B. Erdelyi, A. Afanasev, R.P. Johnson, S.A. Bogacz, Y.S. Derbenev, V.S. Morozov

    2011-03-01

    Next gen­er­a­tion mag­net sys­tems need­ed for cool­ing chan­nels in both neu­tri­no fac­to­ries and muon col­lid­ers will be in­no­va­tive and com­pli­cat­ed. De­sign­ing, sim­u­lat­ing and op­ti­miz­ing these sys­tems is a chal­lenge. Using COSY IN­FIN­I­TY, a dif­fer­en­tial al­ge­bra-based code, to sim­u­late com­pli­cat­ed el­e­ments can allow the com­pu­ta­tion and cor­rec­tion of a va­ri­ety of high­er order ef­fects, such as spher­i­cal and chro­mat­ic aber­ra­tions, that are dif­fi­cult to ad­dress with other sim­u­la­tion tools. As an ex­am­ple, a he­li­cal dipole mag­net has been im­ple­ment­ed and sim­u­lat­ed, and the per­for­mance of an epicyclic para­met­ric ion­iza­tion cool­ing sys­tem for muons is stud­ied and com­pared to sim­u­la­tions made using G4Beam­line, a GEAN­T4 toolk­it.

  6. Studying the magnetic properties of CoSi single crystals

    SciTech Connect

    Narozhnyi, V. N. Krasnorussky, V. N.

    2013-05-15

    The magnetic properties of CoSi single crystals have been measured in a range of temperatures T = 5.5-450 K and magnetic field strengths H {<=} 11 kOe. A comparison of the results for crystals grown in various laboratories allowed the temperature dependence of magnetic susceptibility {chi}(T) = M(T)/H to be determined for a hypothetical 'ideal' (free of magnetic impurities and defects) CoSi crystal. The susceptibility of this ideal crystal in the entire temperature range exhibits a diamagnetic character. The {chi}(T) value significantly increases in absolute value with decreasing temperature and exhibits saturation at the lowest temperatures studied. For real CoSi crystals of four types, paramagnetic contributions to the susceptibility have been evaluated and nonlinear (with respect to the field) contributions to the magnetization have been separated and taken into account in the calculations of {chi}(T).

  7. Recent results from ANKE, WASA-at-COSY, and PAX

    NASA Astrophysics Data System (ADS)

    Khoukaz, Alfons; ANKE,the; WASA-at-COSY; PAX Collaborations

    2015-11-01

    The complementary internal beam experiments ANKE, WASA, and PAX at the COoler-SYnchrotron COSY-Jülich offer unique and exciting opportunities for hadron physics with polarized and unpolarized hadronic probes. Due to the excellent properties of COSY, in combination with the high performance detection systems, a broad experimental program can be covered. One main emphasis of the studies at these facilities are measurements on symmetries in reactions and particle decays as well as high precision studies on particles and their properties. Furthermore, the availability of polarized beams and/or targets allows for investigations on hadronic reactions using the spin degree of freedom or studies towards polarized antiprotons. After an introduction to the experimental facilities at COSY, both recently published results as well as new and unpublished data will be presented and discussed.

  8. COSIE: The Coronal Spectrographic Imager in the EUV

    NASA Technical Reports Server (NTRS)

    Savage, Sabrina; Golub, Leon; Deluca, Ed

    2017-01-01

    COSIE is a solar-observing instrument (currently proposed for mounting onto the ISS) which obtains wide field images of the corona and full Sun spectral images with high sensitivity and rapid cadence. The primary purpose of the instrument is to constrain the global field topology and to track coronal mass ejections from the disk through the inner heliosphere.

  9. Polarization of stored beam by spin-filtering at COSY

    NASA Astrophysics Data System (ADS)

    Ciullo, G.

    2014-01-01

    In the challenging aim to achieve polarized antiproton, the PAX collaboration performed dedicated measurements of the spin-dependent polarizing cross section for p- p scattering at COSY. The result, under a very nice control of the process, agrees with the theoretical previsions, and confirms the pursuability of the spin-filtering for polarizing antiprotons.

  10. Physics Program at COSY-Juelich with Polarized Hadronic Probes

    SciTech Connect

    Kacharava, Andro

    2009-08-04

    Hadron physics aims at a fundamental understanding of all particles and their interactions that are subject to the strong force. Experiments using hadronic probes could contribute to shed light on open questions on the structure of hadrons and their interaction as well as the symmetries of nature. The COoler SYnchrotron COSY at the Forschungszentrum Juelich accelerates protons and deuterons with momenta up to 3.7 GeV/c. The availability of both an electron cooler as well as a stochastic beam cooling system allows for precision measurements, using polarized proton and deuteron beams in combination with polarized Hydrogen or Deuterium targets.This contribution summarizes the ongoing physics program at the COSY facility using ANKE, WASA and TOF detector systems with polarized hadronic probes, highlighting recent results and outlining the new developments.

  11. Microstructural characterization of as-cast Co-Si alloys

    SciTech Connect

    Faria, M.I.S.T. . E-mail: ismenia@phase.faenquil.br; Coelho, G.C.; Nunes, C.A.; Avillez, R.R.

    2006-01-15

    This work presents results of microstructural characterization of as-cast Co-Si alloys. The alloys of different compositions were prepared by arc melting Co (min. 99.97%) and Si (min. 99.99%) under argon atmosphere in a water-cooled copper crucible with a nonconsumable tungsten electrode and titanium getter. All samples were characterized by scanning electron microscopy (SEM) using back-scattered electron (BSE) mode and X-ray diffraction (XRD). A good conformity between the currently accepted Co-Si phase diagram and the experimental results from this work was verified. No indication of the {beta}Co{sub 2}Si was observed in the as-cast microstructures. As in previous investigations, the Co{sub 3}Si phase has not been observed in the samples at room temperature; however, microstructural evidence suggests its stability at high temperature.

  12. Recent Results from the WASA-at-COSY Experiment

    SciTech Connect

    Kupsc, Andrzej

    2011-10-24

    Studies of light meson decays are the key experiments for the WASA detector at COSY-Juelich. One of the world largest data samples of the {eta} meson decays have been recently collected in the pd {yields}{sup 3}He{eta} and in the pp {yields} pp{eta} reactions. The status of the analysis of various decay channels and the further plans for the light meson decay program are presented.

  13. Status and future plans of polarized beams at COSY

    NASA Astrophysics Data System (ADS)

    Lorentz, B.; Gebel, R.; Lehrach, A.; Maier, R.; Prasuhn, D.; Stockhorst, H.

    2011-05-01

    In this paper we report on the present status and future plans of polarized beams in the COSY synchrotron ring. COSY is a synchrotron ring in the momentum range from 295 to 3700 MeV/c. Polarized deuterons and protons are routinely delivered to experiments over the whole momentum range. No depolarization occurs during the acceleration of deuterons in COSY. For polarized protons many depolarizing resonances are crossed without polarization loss. At imperfection resonances, vertical steerer magnets are used to increase the resonance strength, leading to a complete polarization reversal. At intrinsic resonances a fast tune jump quadrupole is used to quickly cross the resonances without loss of polarization. Typical proton polarizations are close to 0.8 below 2.1 GeV/c and about 0.6 for higher momenta. During recent operation an induced depolarizing resonance was used for accurate determination of the relative momentum spread dp/p of the stored beam yielding an accuracy of better than 10-4. For spin filter studies of the PAX collaboration a low beta target section was installed in 2009 and was successfully put into operation early 2010. An upgrade of the EDDA polarimeter electronics and data acquisition system is underway to ensure continued availability of the polarimeter, which is essential for the polarized proton operation of COSY. In the near future it is planned to install a Siberian snake solenoid of 4.5 Tm to be able to provide in addition to vertically polarized protons, longitudinal polarization as well. This solenoid will allow the preparation of a longitudinally polarized beam up to a kinetic energy of 500 MeV.

  14. First internal and external experiments at COSY Juelich

    NASA Astrophysics Data System (ADS)

    Prasuhn, D.; Maier, R.; Bechstedt, U.; Dietrich, J.; Hacker, U.; Martin, S.; Stockhorst, H.; Tölle, R.; Grzonka, D.; Nake, C.; Mosel, F.

    1995-02-01

    The inauguration of the cooler synchrotron COSY Jülich was celebrated on April 1st, 1993. After the first successful acceleration to proton momenta above 800 GeV/ c, beamtimes for experiments were scheduled in parallel to further machine development. The first experiment was the internal target experiment EDDA, which investigated the energy dependence of the p-p interaction. It makes use of a 3 × 4 μm 2 thin CH 2 fiber as an internal target. The thickness of the fiber is more than adequate to achieve high luminosities, so the intensity of the stored beam has to be reduced to 10 7 p. On the other hand, it is thin enough to achieve beam lifetimes of 3 s at 1.4 GeV/ c. Details of the target fabrication and the first experimental results will be discussed. Both external experimental facilities at COSY, the time-of-flight spectrometer, and the magnetic spectrometer BIG KARL use a liquid hydrogen (deuterium) target. The first experiments were carried out at proton energies between 300 MeV and 500 MeV. Also, these experimental data will be presented. Two further internal experiments are prepared for the installation into the COSY ring. The target for the first experiment is a gas-jet target, the second experiment uses ribbon targets for the interaction. The status of both experimental setups will be shown.

  15. Interaction of Cu with CoSi2 with and without TiNx barrier layers

    NASA Astrophysics Data System (ADS)

    Olowolafe, J. O.; Li, Jian; Blanpain, B.; Mayer, J. W.

    1990-09-01

    Thermally induced interactions of Cu with CoSi2, with and without interposed TiNx layers, have been studied using Rutherford backscattering spectrometry, Auger electron spectroscopy, and x-ray diffraction. Cu diffuses through a preformed CoSi2 layer to form the structure Cu/CoSi2/Cu3Si/Si at temperatures above 300 °C, and no dissociation of CoSi2 occurs. A 50 nm TiNx(x≊1) layer is observed to be an effective diffusion barrier up to about 500 °C between Cu and CoSi2.

  16. Ultrafast acquisition of 1H-1H dipolar correlation experiments in spinning elastomers

    NASA Astrophysics Data System (ADS)

    Rouger, Laetitia; Yon, Maxime; Sarou-Kanian, Vincent; Fayon, Franck; Dumez, Jean-Nicolas; Giraudeau, Patrick

    2017-04-01

    We show that two widely used 2D solid-state NMR (ssNMR) pulse sequences can be implemented in an ultrafast (UF) manner, and yield 2D spectra of elastomers in a single scan, under magic-angle spinning. UF 2D ssNMR provides an acceleration of one to several orders of magnitude for classic experiments.

  17. Fabrication of nanometer single crystal metallic CoSi2 structures on Si

    NASA Technical Reports Server (NTRS)

    Nieh, Kai-Wei (Inventor); Lin, True-Lon (Inventor); Fathauer, Robert W. (Inventor)

    1991-01-01

    Amorphous Co:Si (1:2 ratio) films are electron gun-evaporated on clean Si(111), such as in a molecular beam epitaxy system. These layers are then crystallized selectively with a focused electron beam to form very small crystalline Co/Si2 regions in an amorphous matrix. Finally, the amorphous regions are etched away selectively using plasma or chemical techniques.

  18. Test of Time-Reversal Invariance at COSY (TRIC)

    NASA Astrophysics Data System (ADS)

    Eversheim, D.; Valdau, Yu.; Lorentz, B.

    2016-02-01

    At the Cooler Synchrotron COSY a novel (P-even, T-odd) null test of time-reversal invariance to an accuracy of 10-6 is planned as an internal target transmission experiment. The parity conserving time-reversal violating observable is the total cross-section asymmetry Ay,xz. This quantity is measured using a polarized proton beam with an energy of 135 MeV and an internal tensor polarized deuteron target from the PAX atomic beam source. The reaction rate will be determined by the lifetime of the beam. Consequently, the accuracy of the current measurement of the circulating proton beam is crucial for this experiment. Thus, the cooler synchroton ring serves as an ideal forward spectrometer, as a detector, and an accelerator.

  19. Test of time-reversal invariance at COSY (TRIC)

    NASA Astrophysics Data System (ADS)

    Eversheim, D.; Valdau, Yu.; Lorentz, B.

    2013-03-01

    At the Cooler Synchrotron COSY a novel (P-even, T-odd) null test of time-reversal invariance to an accuracy of 10 - 6 is planned as an internal target transmission experiment. The parity conserving time-reversal violating observable is the total cross-section asymmetry Ay,xz. This quantity is measured using a polarized proton beam with an energy of 135 MeV and an internal tensor polarized deuteron target from the PAX atomic beam source. The reaction rate will be measured by means of an integrating beam current transformer. Thus, in this experiment the cooler synchroton ring serves as ideal forward spectrometer, as a detector, and an accelerator.

  20. Water-soluble constituents from aerial roots of Ficus microcarpa.

    PubMed

    Ouyang, M-A; Kuo, Y-H

    2006-01-01

    Three new water-soluble constituents [ficuscarpanoside B (1), (7E,9Z)-dihydrophaseic acid 3-O-beta-D-glucopyranoside (4) and ficuscarpanic acid (6)] and the natural product 2,2'-dihydroxyl ether (7) have been isolated, together with three known compounds [(7S,8R)-syringoylglycerol (2), (7S,8R)-syringoylglycerol-7-O-beta-D-glucopyranoside (3) and icariside D2 (5)] from the aerial roots of Ficus microcarpa. Identification of their structures was achieved by 1D and 2D NMR experiments, including 1H-1H COSY, NOESY, HMQC and HMBC methods and FAB mass spectral data.

  1. Sapinmusaponins F-J, bioactive tirucallane-type saponins from the galls of Sapindus mukorossi.

    PubMed

    Huang, Hui-Chi; Tsai, Wei-Jern; Morris-Natschke, Susan L; Tokuda, Harukuni; Lee, Kuo-Hsiung; Wu, Yang-Chang; Kuo, Yao-Haur

    2006-05-01

    Five new tirucallane-type saponins, sapinmusaponins F-J (1-5), were isolated from the galls of Sapindus mukorossi. The structures of these saponins were elucidated on the basis of spectroscopic analysis including 1D and 2D NMR techniques ((1)H-(1)H COSY, HMQC, HMBC, TOCSY, and NOESY). Compounds 1-5 showed anti-platelet-aggregation effects, but no obvious cytotoxic activity for platelets as assayed by lactate dehydrogenase (LDH) leakage. Compounds 1-5 also showed moderate activity in a 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced Epstein-Barr virus early antigen (EBV-EA) activation assay.

  2. A new chromene from the fruiting bodies of Chroogomphus rutilus.

    PubMed

    Luo, Jie; Zhang, Changhao; Zhu, Heming; Jin, Xuehua; Cao, Shuo; Jin, Mei; Jiang, Zhe; Zheng, Mingshan; Li, Gao

    2015-01-01

    A new chromene, acetic acid 2R-(4,8-dimethylnona-3,7-dienyl)-8-hydroxy-2-methyl-2H-chromen-6-yl ester (1), was isolated from the fruiting bodies of Chroogomphus rutilus, together with six known compounds (2-7). The structures of these compounds were identified based on 1D and 2D NMR, including (1)H-(1)H COSY, HMQC and HMBC spectroscopic methods. Of these seven compounds, 2 and 3 showed cytotoxicity against HSC-T6, SK-Hep1 and A549 cell lines.

  3. Two new diarylheptanoids isolated from the roots of Juglans mandshurica.

    PubMed

    Jin, Mei; Diao, Shengbao; Zhang, Changhao; Cao, Shuo; Sun, Jinfeng; Li, Ren; Jiang, Zhe; Zheng, Mingshan; Son, Jong Keun; Li, Gao

    2015-01-01

    Two new diarylheptanoids, ( - )-threo-3',4″-epoxy-1-(4-hydroxyphenyl)-7-(3-methoxyphenyl)heptan-2,3-diol (1) and (1α,3β,5α,6α)-1,5-epoxy-3,6-dihydroxy-1,7-bis(3-methoxy-4-hydroxy-phenyl)-heptane (2), along with one known diarylheptanoid, rhoiptelol B (3), were isolated from the roots of Juglans mandshurica. The structures of compounds 1 and 2 were identified based on HR-ESI-MS, 1D and 2D NMR including (1)H-(1)H COSY, HMQC, HMBC and NOESY spectroscopic methods.

  4. A fatty acid glycoside from a marine-derived fungus isolated from mangrove plant Scyphiphora hydrophyllacea.

    PubMed

    Zeng, Yan-Bo; Wang, Hui; Zuo, Wen-Jian; Zheng, Bo; Yang, Tao; Dai, Hao-Fu; Mei, Wen-Li

    2012-03-01

    To study the antimicrobial components from the endophytic fungus A1 of mangrove plant Scyphiphora hydrophyllacea Gaertn. F., a new fatty acid glucoside was isolated by column chromatography from the broth of A1, and its structure was identified as R-3-hydroxyundecanoic acid methylester-3-O-α-l-rhamnopyranoside (1) by spectroscopic methods including 1D and 2D NMR (HMQC, (1)H-(1)H COSY and HMBC) and chemical methods. Antimicrobial assay showed compound 1 possessed modest inhibitory effect on Saphylococcus aureus and methicillin-resistant S. aureus (MRSA) using the filter paper disc agar diffusion method.

  5. Jusbetonin, the first indolo[3,2-b]quinoline alkaloid glycoside, from Justicia betonica.

    PubMed

    Subbaraju, Gottumukkala V; Kavitha, Jakka; Rajasekhar, Dodda; Jimenez, Jorge I

    2004-03-01

    A new indolo[3,2-b]quinoline alkaloid glycoside, jusbetonin (1), and three known alkaloids, namely, 10H-quindoline (2), 6H-quinindoline (3), and 5H,6H-quinindolin-11-one (4), have been isolated from the leaves of Justicia betonica. The structure of 1 was established on the basis of 1D and 2D NMR ((1)H-(1)H COSY, HMQC, and HMBC) and HRFABMS data. Compound 1 is the first example of a glycosylated indolo[3,2-b]quinoline alkaloid, while compound 4 was isolated for the first time from a natural source.

  6. 11α-Ethoxy-β-boswellic acid and nizwanone, a new boswellic acid derivative and a new triterpene, respectively, from Boswellia sacra.

    PubMed

    Al-Harrasi, Ahmed; Ali, Liaqat; Ur Rehman, Najeeb; Hussain, Javid; Hussain, Hidayat; Al-Rawahi, Ahmed; Shamim Rizvi, Tania

    2013-08-01

    A new boswellic acid derivative, 11α-ethoxy-β-boswellic acid (EBA; 1) and a new ursane-type triterpene, named nizwanone (2), were isolated from Omani frankincense Boswellia sacra Flueck. together with two known compounds papyriogenin B and rigidenol. The structures of 1 and 2 were elucidated by detailed spectroscopic analysis using (1) H- and (13) C-NMR, (1) H,(1) H-COSY, HMQC, HMBC, and HR-EI-MS techniques. The relative configurations of 1 and 2 were assigned by comparative analysis of the NMR spectral data with those of known analogs together with NOESY experiments. Structures of known compounds were identified by comparison with the reported data.

  7. The O-polysaccharide from the lipopolysaccharide of Providencia stuartii O44 contains L-quinovose, a 6-deoxy sugar rarely occurring in bacterial polysaccharides.

    PubMed

    Kocharova, Nina A; Ovchinnikova, Olga G; Toukach, Filip V; Torzewska, Agnieszka; Shashkov, Alexander S; Knirel, Yuriy A; Rozalski, Antoni

    2005-05-23

    The O-polysaccharide (O-antigen) of Providencia stuartii O44:H4 (strain 3768/51) was obtained by mild acid degradation of the lipopolysaccharide and studied by sugar and methylation analyses along with (1)H and (13)C NMR spectroscopy, including 2D (1)H,(1)H COSY, TOCSY, ROESY, and H-detected (1)H,(13)C HSQC, and HMQC-TOCSY experiments. The O-polysaccharide was found to have a branched hexasaccharide repeating unit of the following structure: [Formula: see text].

  8. Eurycomaoside: a new quassinoid-type glycoside from the roots of Eurycoma longifolia.

    PubMed

    Bedir, Erdal; Abou-Gazar, Hassan; Ngwendson, Julius Ngunde; Khan, Ikhlas Ahmad

    2003-11-01

    A new C(19)-quassinoid-type glycoside has been isolated from the roots of Eurycoma longifolia. The structure elucidation of the compound was achieved by a combination of one- and two-dimensional NMR techniques, including (1)H-(1)H-correlation spectroscopy (COSY), (1)H-(13)C-heteronuclear correlation spectroscopy (HMQC), and (1)H-(13)C-heteronuclear multiple-bond correlation spectroscopy (HMBC), as well as high resolution electrospray ionization Fourier transformation mass spectrometry (HR-ESI-FT-MS) data. The C(1)-glycosidation site in the quassinoid framework is encountered for the first time.

  9. NMR characterisation of inulin-type fructooligosaccharides as the major water-soluble carbohydrates from Matricaria maritima (L.).

    PubMed

    Cérantola, Stéphane; Kervarec, Nelly; Pichon, Roger; Magné, Christian; Bessieres, Marie-Anne; Deslandes, Eric

    2004-10-04

    By use of 1H and 13C NMR spectroscopy including 2D 1H,1H DQF-COSY/TOCSY and 1H,13C HMQC/HMBC experiments, the main water-soluble carbohydrate components extracted from leaves of Matricaria maritima were identified as oligofructans composed of a linear chain of (2-->1)-linked beta-D-fructofuranosyl residues specifying an inulin-type structure. Alpha-D-Glcp-(1-->2)-[beta-D-Fruf-(2-->1)-beta-D-Frucf]n-(2-->1)-beta-D-Fruf.

  10. NMR assignments and X-ray diffraction spectra for two unusual kaurene diterpenes from Erythroxylum barbatum.

    PubMed

    dos Santos, Claudio Costa; Sousa Lima, Mary Anne; Braz-Filho, Raimundo; de Simone, Carlos Alberto; Silveira, Edilberto Rocha

    2005-12-01

    The structural characterization of two new, unusual kaurene diterpenes isolated from roots of Erythroxylum barbatum is described. 1D NMR and several 2D shift-correlated NMR pulse sequences (1H,1H-COSY, HMQC, HMBC and NOESY) were used for structure elucidation and the unambiguous 1H and 13C chemical shifts assignments. Single crystal X-ray diffraction analysis was also used to confirm the final relative configuration of the compounds possessing the C-20 methyl and the CH2-15 methylene groups in cis-orientation.

  11. Spin-Filtering Studies at Cosy and AD

    NASA Astrophysics Data System (ADS)

    Rathmann, F.

    2011-01-01

    Polarized antiprotons provide access to a wealth of single- and double-spin observables, thereby opening a window to physics uniquely accessible with the High Energy Storage Ring (HESR) at FAIR. The physics program proposed by the PAX collaboration includes a first measurement of the transversity distribution of the valence quarks in the proton, a test of the predicted opposite sign of the Sivers-function, related to the quark distribution inside a transversely polarized nucleon in Drell-Yan as compared to semi-inclusive DIS, and a first measurement of the moduli and the relative phase of the time-like electric and magnetic form factors GE,M of the proton. In polarized and unpolarized {pbar p} elastic scattering, open questions like the contribution from the odd charge-symmetry Landshoff-mechanism at large |t|, and spin-effects in the extraction of the forward scattering amplitude at low |t| can be addressed. Provided that antiproton beams with a polarization in excess of 20 % can be obtained with the APR, the HESR at FAIR could be converted into a double-polarized asymmetric bar pp collider by installation of an additional COSY-like ring. In this setup, antiprotons of 3.5 GeV/c collide with protons of 15 GeV/c at c.m. energies of √ s ≈ √ {200} {GeV} with a luminosity in excess of 1031 cm-2s-1. A recent experiment at COSY revealed that ep spin-flip cross sections are too small to cause a detectable depolarization of a stored proton beam. This measurement rules out a proposal to use polarized positrons to polarize an antiproton beam by {e}^ + {bar p} spin-flip interactions. The most promising approach to provide a beam of polarized antiprotons, adopted by the PAX collaboration, is based on spin-filtering using an internal polarized hydrogen gas target - a method that has been shown to work with stored protons. We expect to produce a polarized antiproton beam with ten orders of magnitude higher intensity than secondary polarized antiproton beams previously

  12. The Polarized Target for Spin Filtering Studies at COSY and AD

    SciTech Connect

    Nass, A.; Steffens, E.; Barion, L.; Capiluppi, M.; Lenisa, P.; Stancari, M.; Kleines, H.; Rathmann, F.; Sarkadi, J.

    2007-06-13

    The setup of the polarized target for the spin filtering studies at COSY and AD will be shown together with the planned measurements. The target fulfills all the requirements coming from the experiment.

  13. SPIN-COSY: Spin-Manipulating Polarized Deuterons and Protons

    SciTech Connect

    Leonova, M. A.; Chao, A. W.; Krisch, A. D.; Morozov, V. S.; Raymond, R. S.; Sivers, D. W.; Wong, V. K.; Garishvili, A.; Gebel, R.; Lehrach, A.; Lorentz, B.; Maier, R.; Prasuhn, D.; Stockhorst, H.; Welsch, D.; Hinterberger, F.; Ulbrich, K.; Derbenev, Ya. S.; Kondratenko, A. M.; Stephenson, E. J.

    2009-08-04

    We studied spin manipulation of 1.85 GeV/c polarized deuteron beam stored in COSY obtaining a spin-flip efficiency of 97{+-}1%. We first discovered experimentally and then explained theoretically interesting behavior of the deuteron tensor polarization. We, for the first time, studied systematically spin resonance strengths induced by rf dipoles and solenoids. We found huge disagreements between the strengths measured in controlled Froissart-Stora sweeps and the theoretical values calculated using the well-known formulae. These data instigated re-examination of these formulae. We tested Chao's proposed new matrix formalism for describing the spin dynamics due to a single spin resonance, which may be the first fundamental improvement of the Froissart-Stora equation in that it allows analytic calculation of the beam polarization's behavior inside a resonance. Our measurements of the deuteron's polarization near and inside the resonance agreed precisely with the Chao formalism's predicted oscillations. We tested Kondratenko's proposal to overcome depolarizing resonances by ramping through them with a crossing pattern, which should force the depolarizing contributions to cancel themselves. Our first test of this idea with 2.1 GeV/c protons was not conclusive but a later test with 1.85 GeV/c deuterons demonstrated a rather substantial reduction in the depolarization compared to the tune jump at the same rate.

  14. Spin filtering at COSY and perspectives for PAX

    NASA Astrophysics Data System (ADS)

    Nass, A.

    2014-01-01

    The high physics potential of experiments with stored polarized antiprotons led to the proposal of the PAX [1] experiment (Polarized Antiproton eXperiment) for the High Energy Storage Ring (HESR) of the new FAIR facility at GSI (Darmstadt/Germany). It is proposed to polarize a stored antiproton beam by means of spin filtering by a polarized hydrogen gas target. The feasibility of spin filtering with protons using a transversely polarized hydrogen gas target has been demonstrated in the FILTEX experiment [2] and recently confirmed at the COSY ring in Jülich. A spin filtering experiment using a longitudinally polarized hydrogen gas target is planned after the installation of a siberian snake in 2014. Further measurements including the investigation of pd-breakup reactions [3] and a test of the time reversal (TRIC) [4] are planned using the developed experimental setup. A proposal for a spin-filtering experiment with antiprotons at AD/CERN [5] has been submitted to the CERN SPS comitee to investigate the spin-dependence of the pbar-p and pbar-d interaction. This knowledge is necessary to properly design a dedicated Antiproton-Polarizer Ring.

  15. Subsurface Growth of CoSi2 by Deposition of Co on Si-Capped CoSi2 Seed Regions

    NASA Technical Reports Server (NTRS)

    Fathauer, R. W.; George, T.; Pike, W. T.

    1991-01-01

    At a growth temperature of 800 C, Co deposited on Si(111) diffuses through a Si cap and exhibits oriented growth on buried CoSi2 grains, a process referred to as endotaxy. This occurs preferentially to surface nucleation of CoSi2 provided the thickness of the Si cap is less than a critical value between 100 and 200 nm for a deposition rate of 0.01 nm/s. Steady-state endotaxy is modeled under the assumption that the process is controlled by Co diffusion.

  16. Subsurface Growth of CoSi2 by Deposition of Co on Si-Capped CoSi2 Seed Regions

    NASA Technical Reports Server (NTRS)

    Fathauer, R. W.; George, T.; Pike, W. T.

    1991-01-01

    At a growth temperature of 800 C, Co deposited on Si(111) diffuses through a Si cap and exhibits oriented growth on buried CoSi2 grains, a process referred to as endotaxy. This occurs preferentially to surface nucleation of CoSi2 provided the thickness of the Si cap is less than a critical value between 100 and 200 nm for a deposition rate of 0.01 nm/s. Steady-state endotaxy is modeled under the assumption that the process is controlled by Co diffusion.

  17. Interfacial stability of CoSi2/Si structures grown by molecular beam epitaxy

    NASA Technical Reports Server (NTRS)

    George, T.; Fathauer, R. W.

    1992-01-01

    The stability of CoSi2/Si interfaces was examined in this study using columnar silicide structures grown on (111) Si substrates. In the first set of experiments, Co and Si were codeposited using MBE at 800 C and the resulting columnar silicide layer was capped by epitaxial Si. Deposition of Co on the surface of the Si capping layer at 800 C results in the growth of the buried silicide columns. The buried columns grow by subsurface diffusion of the deposited Co, suppressing the formation of surface islands of CoSi2. The column sidewalls appear to be less stable than the top and bottom interfaces, resulting in preferential lateral growth and ultimately in the coalescence of the columns to form a continuous buried CoSi2 layer. In the second set of experiments, annealing of a 250 nm-thick buried columnar layer at 1000 C under a 100 nm-thick Si capping layer results in the formation of a surface layer of CoSi2 with a reduction in the sizes of the CoSi2 columns. For a sample having a thicker Si capping layer the annealing leads to Ostwald ripening producing buried equiaxed columns. The high CoSi2/Si interfacial strain could provide the driving force for the observed behavior of the buried columns under high-temperature annealing.

  18. Interfacial stability of CoSi2/Si structures grown by molecular beam epitaxy

    NASA Technical Reports Server (NTRS)

    George, T.; Fathauer, R. W.

    1992-01-01

    The stability of CoSi2/Si interfaces was examined in this study using columnar silicide structures grown on (111) Si substrates. In the first set of experiments, Co and Si were codeposited using MBE at 800 C and the resulting columnar silicide layer was capped by epitaxial Si. Deposition of Co on the surface of the Si capping layer at 800 C results in the growth of the buried silicide columns. The buried columns grow by subsurface diffusion of the deposited Co, suppressing the formation of surface islands of CoSi2. The column sidewalls appear to be less stable than the top and bottom interfaces, resulting in preferential lateral growth and ultimately in the coalescence of the columns to form a continuous buried CoSi2 layer. In the second set of experiments, annealing of a 250 nm-thick buried columnar layer at 1000 C under a 100 nm-thick Si capping layer results in the formation of a surface layer of CoSi2 with a reduction in the sizes of the CoSi2 columns. For a sample having a thicker Si capping layer the annealing leads to Ostwald ripening producing buried equiaxed columns. The high CoSi2/Si interfacial strain could provide the driving force for the observed behavior of the buried columns under high-temperature annealing.

  19. New cycloartane-type triterpenes from Marcetia latifolia (Melastomataceae) and in silico studies on Candida parapsilosis protease.

    PubMed

    Leite, Tonny C C; Leite, Franco H A; Vieira, Ivo J C; Braz Filho, Raimundo; Branco, Alexsandro

    2013-08-01

    We have previously reported the antimicrobial activity of the ethyl acetate extract of Marcetia latifolia, particularly against Candida parapsilosis. In this work we describe the isolation of two new cycloartane-type triterpenes, 28,29-bis-norcycloartan-3beta,4alpha-diol (1) and 28,29-bis-norcycloart-24-en-3beta,4alpha-diol (2) from the same extract. These compounds were mainly characterized by one- (1H, 13C and APT) and two-dimensional (1H-1H-COSY, 1H-1H-NOESY, HMQC and HMBC) NMR spectroscopy, mass spectrometry and comparison with published structural data. In addition, the activity of triterpenes 1 and 2 on the Candida protease target was investigated by in silico methods using molecular docking.

  20. Disorder dependent half-metallicity in Mn{sub 2}CoSi inverse Heusler alloy

    SciTech Connect

    Singh, Mukhtiyar; Saini, Hardev S.; Thakur, Jyoti; Reshak, Ali H.; Kashyap, Manish K.

    2013-12-15

    Heusler alloys based thin-films often exhibit a degree of atomic disorder which leads to the lowering of spin polarization in spintronic devices. We present ab-initio calculations of atomic disorder effects on spin polarization and half-metallicity of Mn{sub 2}CoSi inverse Heusler alloy. The five types of disorder in Mn{sub 2}CoSi have been proposed and investigated in detail. The A2{sub a}-type and B2-type disorders destroy the half-metallicity whereas it sustains for all disorders concentrations in DO{sub 3a}- and A2{sub b}-type disorder and for smallest disorder concentration studied in DO{sub 3b}-type disorder. Lower formation energy/atom for A2{sub b}-type disorder than other four disorders in Mn{sub 2}CoSi advocates the stability of this disorder. The total magnetic moment shows a strong dependence on the disorder and the change in chemical environment. The 100% spin polarization even in the presence of disorders explicitly supports that these disorders shall not hinder the use of Mn{sub 2}CoSi inverse Heusler alloy in device applications. - Graphical abstract: Minority-spin gap (E{sub g↓}) and HM gap (E{sub sf}) as a function of concentrations of various possible disorder in Mn{sub 2}CoSi inverse Heusler alloy. The squares with solid line (black color)/dotted line (blue color)/dashed line (red color) reperesents E{sub g↓} for DO{sub 3a}-/DO{sub 3b}-/A2{sub b}-type disorder in Mn{sub 2}CoSi and the spheres with solid line (black color)/dottedline (blue color)/dashed line (red color) represents E{sub sf} for DO{sub 3a}-/DO{sub 3b}-/A2{sub b}-type disorder in Mn{sub 2}CoSi. - Highlights: • The DO{sub 3}- and A2-type disorders do not affect the half-metallicity in Mn{sub 2}CoSi. • The B2-type disorder solely destroys half-metallicity in Mn{sub 2}CoSi. • The A2-type disorder most probable to occur out of all three types. • The total spin magnetic moment strongly depends on the disorder concentrations.

  1. Interlayer coupling in Co/Si multilayers (abstract)

    NASA Astrophysics Data System (ADS)

    Inomata, K.; Saito, Y.

    1997-04-01

    Although the picture of antiferromagnetic (AF) coupling in metal/metal multilayers is well-established, it is not clear how the picture can be extensively modified for coupling across insulating or semiconducting spacer layers. Unusual temperature sensitive interlayer coupling has recently been observed in Fe/Si/Fe sandwiches and Fe/Si multilayers.123 The spacer has been claimed to be a metastable metallic FeSi with CsCl structure in the Fe/Si multilayers,4 and a transition from AF coupling to biquadratic coupling has been observed with decreasing temperature in Fe/FeSi multilayers.56 In this study, interlayer coupling has been investigated as a function of nominal Si layer thickness tSi in Co/Si multilayers. The multilayers were grown at ambient temperature on water cooled thermally oxidized Si substrates by ion beam sputtering at a base pressure of 3×10-7 Torr. The sputtering was conducted using 1.8×10-4 Torr Ar ions and an acceleration voltage of 400 V. Co was shown to have hcp structure with (002) texture by x-ray and transmission electron diffractions. From the magnetization curve, the coupling was ferromagnetic below tSi=0.8 nm, changed to antiferromagnetic above 0.8 nm Si and disappeared at tSi>1.7 nm, exhibiting nonoscillation. We have estimated interlayer coupling J between Co layers across the spacer from the saturation field Hs using the relation of Hs=4J/dMs, where d is the Co layer thickness and Ms is the saturation magnetization. The interlayer coupling was also investigated using FMR for Co/Si/Co sandwiches, which demonstrates an exponentially decay of the coupling with increasing tSi, and gives AF coupling of J=-3.6×10-2 erg/cm2 for a 10 nm Co/1.5 nm Si/10 nm Co sandwich. The cross-sectional transmission electron microscopy exhibited the spacer consisting of Co silicide with amorphous nature, formed in the interface. Temperature dependence of the coupling was investigated using FMR and compared with that of Fe/Si multilayers. Substrate dependence

  2. The TRIC Experiment: A P-even Time-Reversal Invariance Test at COSY

    SciTech Connect

    Eversheim, P.D.

    2005-10-26

    At the cooler synchrotron COSY at Juelich a novel (P-even, T-odd) true null test was proposed, that is supposed to measure the time-reversal invariance sensitive observable, the total cross-section correlation Ay,xz, to an accuracy of 10-6. This observable is measured in a transmission experiment of a circulating vector polarized (Py) proton beam through an internal tensor polarized (Pxz) atomic deuteron target. The experiment uses the COSY facility as an accelerator, an ideal forward spectrometer, and as a detector. At present the experimental focus lies on the development of a precise current measurement via a Beam-Current-Transformer (BCT), its precise read-out and analysis. So far, we succeeded to meet the BCT's accuracy specification. With the help of this accurate current measurement the development of a proper long living proton beam in COSY at the optimum energy, where the experiment has its highest sensitivity, is in progress.

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

    PubMed

    Tzvetkova, Pavleta; Luy, Burkhard

    2016-05-01

    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.COSY principle to spin systems consisting of a Spin 1 coupled to a spin ½ nucleus, which allows the determination of the sign of the quadrupolar coupling of the Spin 1 nucleus relative to the heteronuclear coupling between the spins. The so-called Q.E.COSY approach is demonstrated with its sign-sensitivity using variable angle NMR, stretched gels and liquid crystalline phases applied to various CD and CD3 groups. Especially the sign-sensitive measurement of residual quadrupolar couplings that remain unresolved in conventional deuterium 1D spectra is shown.

  4. Ballistic-carrier spectroscopy of the CoSi2/Si interface

    NASA Technical Reports Server (NTRS)

    Kaiser, W. J.; Hecht, M. H.; Fathauer, R. W.; Bell, L. D.; Lee, E. Y.; Davis, L. C.

    1991-01-01

    Ballistic-electron-emission microscopy and related ballistic-hole and carrier-scattering spectroscopies were used to investigate carrier transport in the epitaxial CoSi2/Si system. An unexpected degree of variation in interface transmission was observed despite the high crystal quality of the epitaxial silicide layer. Furthermore, clear evidence of the CoSi2 band structure was observed, which has a dramatic effect on interface transport. The major effect of the silicide band structure is to increase the interfacial barrier to electron transmission to a value in excess of the Schottky barrier height.

  5. Exclusive near threshold two-pion production with the MOMO experiment at COSY

    NASA Astrophysics Data System (ADS)

    Bavink, S.; Bellemann, F.; Berg, A.; Bisplinghoff, J.; Bohlscheid, G.; Ernst, J.; Henrich, C.; Hinterberger, F.; Ibald, R.; Jahn, R.; Jarczyk, L.; Joosten, R.; Kozela, A.; Machner, H.; Magiera, A.; Maschuw, R.; Mayer-Kuckuk, T.; Mertler, G.; Munkel, J.; Neumann-Cosel, P. v.; Rosendaal, D.; Rossen, P. v.; Schnitker, H.; Scho, K.; Smyrski, J.; Strzalkowski, A.; Tölle, R.; Wurzinger, R.

    1998-03-01

    Near threshold two pion production via the reaction pd → 3Heπ +π - was measured kinematically complete with the MOMO experiment at COSY. A remarkable deviation of the obtained two pion invariant mass spectra from phase space as well as a predominant back to back and sidewise emission of the two pions was observed.

  6. Exclusive near threshold two-pion production with the MOMO experiment at COSY

    NASA Astrophysics Data System (ADS)

    Bavink, S.; Bellemann, F.; Berg, A.; Bisplinghoff, J.; Bohlscheid, G.; Ernst, J.; Henrich, C.; Hinterberger, F.; Ibald, R.; Jahn, R.; Jarczyk, L.; Joosten, R.; Kozela, A.; Machner, H.; Magiera, A.; Maschuw, R.; Mayer-Kuckuk, T.; Mertler, G.; Munkel, J.; Neumann-Cosel, P. v.; Rosendaal, D.; Rossen, P. v.; Schnitker, H.; Scho, K.; Smyrski, J.; Strzalkowski, A.; Tölle, R.; Wurzinger, R.

    1997-05-01

    Near threshold two pion production via the reaction pd→3Heπ+π- was measured kinematically complete with the MOMO experiment at COSY. A remarkable deviation of the obtained two pion invariant mass spectra from phase space as well as a predominant sidewise and back to back emission of the two mesons was observed.

  7. Ballistic-Charge-Carrier Spectroscopy Of CoSi(2)/Si Interfaces

    NASA Technical Reports Server (NTRS)

    Hecht, Michael H.; Kaiser, William J.; Fathauer, Robert W.; Bell, Lloyd D.; Lee, Edwin Y.

    1993-01-01

    Report discusses experiments in which ballistic-electron-emission microscopy (BEEM) and related ballistic-hole and charge-carrier-scattering spectroscopies used to investigate transport of electric-charge carriers (electrons and holes) in epitaxial CoSi2/Si system.

  8. Development of cluster-jet targets: From COSY-11 to FAIR

    SciTech Connect

    Taeschner, A.; General, S.; Otte, J.; Rausmann, T.; Khoukaz, A.

    2007-11-07

    The development of cluster-jet targets of Muenster type is presented. Starting with the first target installed at the COSY-11 experiment the progress is described which was made at a cluster-jet target facility installed in Muenster leading to a prototype for a cluster-jet target for the upcoming PANDA experiment at FAIR.

  9. The upcoming balloon campaign of the Compton Spectrometer and Imager (COSI)

    NASA Astrophysics Data System (ADS)

    Chiu, J.-L.; Boggs, S. E.; Chang, H.-K.; Tomsick, J. A.; Zoglauer, A.; Amman, M.; Chang, Y.-H.; Chou, Y.; Jean, P.; Kierans, C.; Lin, C.-H.; Lowell, A.; Shang, J.-R.; Tseng, C.-H.; von Ballmoos, P.; Yang, C.-Y.

    2015-06-01

    The Compton Spectrometer and Imager (COSI), formerly known as the Nuclear Compton Telescope (NCT), is a balloon-borne soft gamma-ray telescope (0.2-5 MeV) designed to study astrophysical sources of nuclear-line emission and gamma-ray polarization. The heart of COSI is a compact array of cross-strip germanium detectors (GeDs), providing excellent spectral resolution ( 0.2 - 1 %) and the capability to track individual photon interactions with full 3D position resolution to 1.6 mm3. COSI is built upon considerable heritage from the previous NCT balloon instrument, which has flown successfully on two conventional balloon flights to date. The Crab Nebula was detected at a significance of 6σ in the second flight, which is the first reported detection of an astrophysical source by a compact Compton telescope. COSI has been upgraded from the previous NCT instrument to be an Ultra Long Duration Balloon (ULDB) payload, utilizing a new detector configuration optimized for polarization sensitivity and employing a mechanical cryocooler to remove consumables (LN2) for ULDB flights. The instrument is being integrated for a ULDB flight in December 2014 from Antarctica on a superpressure balloon. Here we will present the redesign of the instrument and our current progress in preparing for the flight.

  10. Comparison of Schottky barrier heights of CoSi2 formed from evaporated or crystalline Si

    NASA Astrophysics Data System (ADS)

    Lien, C.-D.; Finetti, M.; Nicolet, M.-A.

    1984-09-01

    Three kinds of samples were used to form Co suicides by thermal annealing: firstly, a Co film of about 370 Å thick, evaporated on a (100) single crystal Si (Si c /Co); secondly, an evaporated boron-containing Si (Si e (B)) layer on the top of the first sample (Si c /Co/Si e (B)). The last sample is in the Co film of the first sample we deposited a Sie(B) layer (Si c /Co/Si e (B)/Co). A laterally uniform CoSi2 layer can be formed from the second and the third samples by annealing at 450 °C. In the first sample, the CoSi2 can be formed only at temperatures above 500 °C and the disilicide is laterally less uniform than in the second and third samples. The Schottky barrier heights of the three samples derived from the forward and reverse I V characteristics show that the barrier height is 0.01 0.02eV higher in the uniform case than in the nonuniform case.

  11. Determination of long-range scalar 1H-1H coupling constants responsible for polarization transfer in SABRE

    NASA Astrophysics Data System (ADS)

    Eshuis, Nan; Aspers, Ruud L. E. G.; van Weerdenburg, Bram J. A.; Feiters, Martin C.; Rutjes, Floris P. J. T.; Wijmenga, Sybren S.; Tessari, Marco

    2016-04-01

    SABRE (Signal Amplification By Reversible Exchange) nuclear spin hyperpolarization method can provide strongly enhanced NMR signals as a result of the reversible association of small molecules with para-hydrogen (p-H2) at an iridium metal complex. The conversion of p-H2 singlet order to enhanced substrate proton magnetization within such complex is driven by the scalar coupling interactions between the p-H2 derived hydrides and substrate nuclear spins. In the present study these long-range homonuclear couplings are experimentally determined for several SABRE substrates using an NMR pulse sequence for coherent hyperpolarization transfer at high magnetic field. Pyridine and pyrazine derivatives appear to have a similar ∼1.2 Hz 4J coupling to p-H2 derived hydrides for their ortho protons, and a much lower 5J coupling for their meta protons. Interestingly, the 4J hydride-substrate coupling for five-membered N-heterocyclic substrates is well below 1 Hz.

  12. Determination of long-range scalar (1)H-(1)H coupling constants responsible for polarization transfer in SABRE.

    PubMed

    Eshuis, Nan; Aspers, Ruud L E G; van Weerdenburg, Bram J A; Feiters, Martin C; Rutjes, Floris P J T; Wijmenga, Sybren S; Tessari, Marco

    2016-04-01

    SABRE (Signal Amplification By Reversible Exchange) nuclear spin hyperpolarization method can provide strongly enhanced NMR signals as a result of the reversible association of small molecules with para-hydrogen (p-H2) at an iridium metal complex. The conversion of p-H2 singlet order to enhanced substrate proton magnetization within such complex is driven by the scalar coupling interactions between the p-H2 derived hydrides and substrate nuclear spins. In the present study these long-range homonuclear couplings are experimentally determined for several SABRE substrates using an NMR pulse sequence for coherent hyperpolarization transfer at high magnetic field. Pyridine and pyrazine derivatives appear to have a similar ∼1.2 Hz (4)J coupling to p-H2 derived hydrides for their ortho protons, and a much lower (5)J coupling for their meta protons. Interestingly, the (4)J hydride-substrate coupling for five-membered N-heterocyclic substrates is well below 1 Hz.

  13. Precise momentum determination of the external COSY proton beam near 1930 MeV//c

    NASA Astrophysics Data System (ADS)

    Betigeri, M. G.; Bojowald, J.; Budzanowski, A.; Chatterjee, A.; Drochner, M.; Ernst, J.; Förtsch, S.; Freindl, L.; Frekers, D.; Garske, W.; Grewer, K.; Hamacher, A.; Hawash, M.; Igel, S.; Ilieva, I.; Jahn, R.; Jarczyk, L.; Kemmerling, G.; Kilian, K.; Kliczewski, S.; Klimala, W.; Kolev, D.; Kutsarova, T.; Lieb, B. J.; Lippert, G.; Machner, H.; Magiera, A.; Maier, R.; Nann, H.; Plendl, H. S.; Protic, D.; Razen, B.; von Rossen, P.; Roy, B.; Siudak, R.; Smyrski, J.; Strzałkowski, A.; Tsenov, R.; Zolnierczuk, P. A.; Zwoll, K.; GEM Collaboration

    1999-05-01

    We present a method to determine precisely the absolute momentum of the external proton beam from the Jülich Cooler Synchrotron COSY near 1930 MeV /c. In the pp → d π+ reaction at 1930.477 MeV /c incident beam momentum, the forward going pions ( θ c.m.=0° ) and the backward going deuterons ( θ c.m.=180° ) have the same laboratory momentum. Such coincident pion-deuteron events are detected in the focal plane of the magnetic spectrometer BIG KARL located at θ lab=0° . Using the nearly linear dependence of the difference between the measured pion and deuteron momenta as a function of the proton beam momentum, the absolute momentum of the external proton beam from COSY near 1930 MeV /c was determined with a precision of 5.2×10 -5.

  14. The H and D Polarized Target for Spin-Filtering Measurements at COSY

    NASA Astrophysics Data System (ADS)

    Ciullo, Giuseppe; Statera, Marco; Lenisa, Paolo; Nass, Alexander; Tagliente, Giuseppe

    2016-04-01

    In the main frame of the PAX (Polarized Antiproton eXperiments) collaboration, which engaged the challenging purpose of polarizing antiproton beams, the possibility to have H or D polarized targets requires a daily switchable source and its diagnostics: mainly change is a dual cavity tunable for H and D. The commissioning of PAX has been fullfilled, for the transverse case, on the COSY (COoler SYnchrotron) proton ring, achieving milestones on spin-dependent cross-section measurements. Now the longitudinal case could provide sensitive polarization results. An H or D source allows the exploration of the spin-filtering process with a deuterium polarized target, and opens new chances for testing Time Reversal Invariance at COSY (TRIC).

  15. Endotaxial growth of CoSi2 within (111) oriented Si in a molecular beam epitaxy system

    NASA Technical Reports Server (NTRS)

    George, T.; Fathauer, R. W.

    1991-01-01

    A new mode of growth is reported in which buried metallic layers can be fabricated within a single-crystal semiconductor through preferential subsurface growth on previously-grown 'seed' regions. The deposition of Co at 800 C at a rate of 0.01 nm/s on (111) Si substrates containing buried CoSi2 columns 40-100 nm below the Si surface results in the growth and coalescence of these subsurface columns. The formation of a CoSi2 layer on the Si surface is suppressed by this growth mode. It is proposed that the high diffusion rate of Co at 800 C, coupled with the high growth rate of CoSi2 at the subsurface columns, is responsible for this preferred 'endotaxial' growth mode. This growth technique was used to produce a continuous buried single-crystal layer of CoSi2 under a single-crystal Si capping layer.

  16. Endotaxial growth of CoSi2 within (111) oriented Si in a molecular beam epitaxy system

    NASA Technical Reports Server (NTRS)

    George, T.; Fathauer, R. W.

    1991-01-01

    A new mode of growth is reported in which buried metallic layers can be fabricated within a single-crystal semiconductor through preferential subsurface growth on previously-grown 'seed' regions. The deposition of Co at 800 C at a rate of 0.01 nm/s on (111) Si substrates containing buried CoSi2 columns 40-100 nm below the Si surface results in the growth and coalescence of these subsurface columns. The formation of a CoSi2 layer on the Si surface is suppressed by this growth mode. It is proposed that the high diffusion rate of Co at 800 C, coupled with the high growth rate of CoSi2 at the subsurface columns, is responsible for this preferred 'endotaxial' growth mode. This growth technique was used to produce a continuous buried single-crystal layer of CoSi2 under a single-crystal Si capping layer.

  17. Application of z-COSY experiment and its variant for accurate chiral discrimination by 1H NMR

    NASA Astrophysics Data System (ADS)

    Prabhu, Uday Ramesh; Suryaprakash, N.

    2010-02-01

    We report the application of z-COSY experiment and a band selected version of it by employing a selective 90° pulse entitled BASE-z-COSY for precise chiral discrimination, quantification of enantiomeric excess and the analyses of the 1H NMR spectra of chiral molecules aligned in the chiral liquid crystalline solvent poly- γ-benzyl- L-glutamate (PBLG). We have demonstrated their applicability for obtaining very high resolution in the 1H NMR spectra of small organic molecules. It is well known that the commonly employed z-COSY experiment disentangles the spectral complexity, provides pure phase spectra with high resolution, aids in the complete spectral analyses, in addition to yielding information on relative signs of the couplings. The BASE-z-COSY experiment possesses all these properties, permits the measure of enantiomeric excess, in addition to large saving of instrument time.

  18. Magnetic structure of the magnetoelectric material Ca2CoSi2O7

    NASA Astrophysics Data System (ADS)

    Sazonov, A.; Hutanu, V.; Meven, M.; Roth, G.; Murakawa, H.; Tokura, Y.; Guduru, V. K.; Peters, L. C. J. M.; Zeitler, U.; Kiss, L. F.; Szaller, D.; Náfrádi, B.; Kézsmárki, I.

    2017-05-01

    Detailed investigation of Ca2CoSi2O7 was performed in its low-temperature magnetoelectric state combining neutron diffraction with magnetization measurements on single crystals. The crystal and magnetic structures well below the antiferromagnetic transition temperature of TN≈5.7 K were determined using neutron diffraction. Neutron diffraction data imply no structural phase transition from 10 K down to 2.5 K and are well described within the orthorhombic space group P 21212 with a 3 ×3 ×1 supercell compared with the high-temperature unmodulated state (tetragonal space group P 4 ¯21m ). We found that in zero magnetic field the magnetic space group is P 2121'2' with antiferromagnetic order along the [100] or [010] axes for two types of 90∘ twin domains, while neighboring spins along the [001] axis are ordered ferromagnetically. A noncollinear spin arrangement due to small canting within the a b plane is allowed by symmetry and leads to the existence of the tiny spontaneous magnetization below TN. The ordered moment with a magnitude of about 2.8 μB/Co2 + at 2.5 K lies in the a b plane. Distinct differences between the magnetic structure of Ca2CoSi2O7 as compared to those of Ba2CoGe2O7 and Sr2CoSi2O7 are discussed.

  19. Negative ion source development at the cooler synchrotron COSY/Jülich

    NASA Astrophysics Data System (ADS)

    Felden, O.; Gebel, R.; Maier, R.; Prasuhn, D.

    2013-02-01

    The Nuclear Physics Institute at the Forschungszentrum Jülich, a member of the Helmholtz Association, conducts experimental and theoretical basic research in the field of hadron, particle, and nuclear physics. It operates the cooler synchrotron COSY, an accelerator and storage ring, which provides unpolarized and polarized proton and deuteron beams with beam momenta of up to 3.7 GeV/c. Main activities of the accelerator division are the design and construction of the high energy storage ring HESR, a synchrotron and part of the international FAIR project, and the operation and development of COSY with injector cyclotron and ion sources. Filament driven volume sources and a charge exchange colliding beams source, based on a nuclear polarized atomic beam source, provide unpolarized and polarized H- or D- routinely for more than 6500 hours/year. Within the Helmholtz Association's initiative Accelerator Research and Development, ARD, the existing sources at COSY, as well as new sources for future programs, are investigated and developed. The paper reports about these plans, improved pulsed beams from the volume sources and the preparation of a source for the ELENA project at CERN.

  20. The Storage Cell for the Tri-Experiment at COSY-JÜLICH

    NASA Astrophysics Data System (ADS)

    Felden, O.; Gebel, R.; Glende, M.; Lehrach, A.; Maier, R.; Prasuhn, D.; von Rossen, P.; Bisplinghoff, J.; Eversheim, P. D.; Hinterberger, F.

    2002-04-01

    At the EDDA experiment in the cooler synchrotron COSY in Jülich an atomic beam target is used which provides the designed polarization and density distribution. To increase the target density significantly a storage cell has been developed and implemented. This will contribute to a higher accuracy for the test of Time Reversal Invariance (TRI) which will be performed at the EDDA target place. To obtain the higher luminosity the target density and the transmission of the COSY beam through the cell were determined in their dependence on the cell aperture. Low storage cell apertures increase the target density in the cell but reduce the transmission of the circulating proton beam. To find the optimal cell design the transmission of the COSY beam was measured with movable scrapers and tested with an aperture at EDDA simulating the storage cell. The target density was calculated by Monte Carlo simulations for several cell geometries. An additional gain in target density is achieved by cooling the cell. A Teflon coating of the cell reduces depolarization of the target gas. First measurements with the EDDA detector have shown that the target density as well as the polarization are within the range of the expected values.

  1. The Scalar Resonances a0/f0(980) at COSY

    SciTech Connect

    Buescher, M.

    2006-02-11

    Fundamental properties of the scalar resonances a0/f0(980), like their masses, widths and couplings to KK-bar, are poorly known. In particular, precise knowledge of the latter quantity would be of great importance since it can be related to the KK-bar content of these resonances.An experimental program is under way at COSY-Juelich aiming at the extraction of the isospin violating a0/f0 mixing amplitude {lambda} which is in leading order proportional to the product of the coupling constants of the a0 and f0 to kaons. a0/f0 production is studied in pp, pn and dd interactions, both for the KK-bar and the {pi}{eta}/{pi}{pi} decays, using the ANKE and WASA spectrometers. The latter will be available for measurements at COSY in 2007.As a first step, isovector KK-bar production has been measured in the reaction pp {yields} dK+K-bar0. The data reveal dominance of the a{sub 0}{sup +} channel, thus demonstrating the feasibility of scalar meson studies at COSY. Analyses of KK-bar- and K-bard-FSI effects yield the corresponding scattering lengths, a(KK-bar)I=1 = -(0.02 {+-} 0.03) - i(0.61 {+-} 0.05) fm and vertical bar Re a(K-bard) vertical bar {<=}1.3 fm, Im a(K-bard){<=}1.3 fm.

  2. Xenon-ion-induced and thermal mixing of Co/Si bilayers and their interplay

    NASA Astrophysics Data System (ADS)

    Novaković, M.; Zhang, K.; Popović, M.; Bibić, N.; Hofsäss, H.; Lieb, K. P.

    2011-05-01

    Studies on ion-irradiated transition-metal/silicon bilayers demonstrate that interface mixing and silicide phase formation depend sensitively on the ion and film parameters, including the structure of the metal/Si interface. Thin Co layers e-gun evaporated to a thickness of 50 nm on Si(1 0 0) wafers were bombarded at room temperature with 400-keV Xe + ions at fluences of up to 3 × 10 16 cm -2. We used either crystalline or pre-amorphized Si wafers the latter ones prepared by 1.0-keV Ar-ion implantation. The as-deposited or Xe-ion-irradiated samples were then isochronally annealed at temperatures up to 700 °C. Changes of the bilayer structures induced by ion irradiation and/or annealing were investigated with RBS, XRD and HRTEM. The mixing rate for the Co/c-Si couples, Δ σ2/ Φ = 3.0(4) nm 4, is higher than the value expected for ballistic mixing and about half the value typical for spike mixing. Mixing of pre-amorphized Si is much weaker relative to crystalline Si wafers, contrary to previous results obtained for Fe/Si bilayers. Annealing of irradiated samples produces very similar interdiffusion and phase formation patterns above 400 °C as in the non-irradiated Co/Si bilayers: the phase evolution follows the sequence Co 2Si → CoSiCoSi 2.

  3. A new COmpact hyperSpectral Imaging system (COSI) for UAS

    NASA Astrophysics Data System (ADS)

    Sima, Aleksandra; Baeck, Pieter-Jan; Delalieux, Stephanie; Livens, Stefan; Blommaert, Joris; Delauré, Bavo; Boonen, Miet

    2016-04-01

    This presentation gives an overview of the new COmpact hyperSpectral Imaging (COSI) system recently developed at the Flemish Institute for Technological Research (VITO, Belgium) and suitable for multirotor Remotely Piloted Aircraft Systems (RPAS) platforms. The camera is compact and lightweight, with a total mass of less than 500g including: an embedded computer, storage and power distribution unit. Such device miniaturization was possible thanks to the application of linear variable filters technology, in which image lines in the across flight direction correspond to different spectral bands as well as a different location on the ground (frame camera). The scanning motion is required to retrieve the complete spectrum for every point on the ground. The COSI camera captures data in 72 narrow (FWHM: 5nm to 10 nm) bands in the spectral range of 600-900 nm. Such spectral information is highly favourable for vegetation studies, since the main chlorophyll absorption feature centred around 680 nm is measured, as well as, the red-edge region (680 nm to 730 nm) which is often linked to plant stress. The NIR region furthermore reflects the internal plant structure, and is often linked to leaf area index and plant biomass. Next to the high spectral resolution, the COSI imager also provides a very high spatial data resolution i.e. images captured with a 9mm lens at 40m altitude cover a swath of ~40m with a ~2cm ground sampling distance. A dedicated data processing chain transforms the raw images into various information and action maps representing the status of the vegetation health and thus allowing for optimization of the management decisions within agricultural fields. In a number of test flights, hyperspectral COSI imager data were acquired covering diverse environments, e.g.: strawberry fields, natural grassland or pear orchards. Next to the COSI system overview, examples of collected data will be presented together with the results of the spectral data analysis. Lessons

  4. Transmission electron microscopy study of the formation of epitaxial CoSi2/Si (111) by a room-temperature codeposition technique

    NASA Technical Reports Server (NTRS)

    D'Anterroches, Cecile; Yakupoglu, H. Nejat; Lin, T. L.; Fathauer, R. W.; Grunthaner, P. J.

    1988-01-01

    Co and Si have been codeposited on Si (111) substrates near room temperature in a stoichiometric 1:2 ratio in a molecular beam epitaxy system. Annealing of these deposits yields high-quality single-crystal CoSi2 layers. Transmission electron microscopy has been used to examine as-deposited layers and layers annealed at 300, 500, and 600 C. Single-crystal epitaxial grains of CoSi2 embedded in a matrix of amorphous Co/Si are observed in as-deposited samples, while the layer is predominantly single-crystal, inhomogeneously strained CoSi2 at 300 C. At 600 C, a homogeneously strained single-crystal layer with a high density of pinholes is observed. In contrast to other solid phase epitaxy techniques used to grow CoSi2 on Si (111), no intermediate silicide phases are observed prior to the formation of CoSi2.

  5. First Experiments with the Polarized Internal Gas Target (PIT) at ANKE/COSY

    SciTech Connect

    Engels, R.; Lorentz, B.; Prasuhn, D.; Rathmann, F.; Sarkadi, J.; Schleichert, R.; Seyfarth, H.; Stroeher, H.; Chiladze, D.; Dymov, S.; Grigoryev, K.; Mikirtychyants, M.; Kacharava, A.; Klehr, F.; Mikirtychyants, S.; Vasilyev, A.; Schieck, H. Paetz gen.; Steffens, E.

    2009-08-04

    For future few-nucleon interaction studies with polarized beams and targets at COSY-Juelich, a polarized internal storage-cell gas target was implemented at the magnet spectrometer ANKE. First commissioning of the polarized Atomic Beam Source (ABS) at ANKE was carried out and some improvements of the system have been done. Storage-cell tests to determine the COSY beam dimensions have been performed. Electron cooling combined with stacking and stochastic cooling have been studied. Experiments with N{sub 2} gas in the storage cell to simulate the background produced by beam interaction with the aluminum cell walls were performed to investigate the beam heating by the target gas. The analysis of the d-vectorp-vector->dp and d-vectorp-vector->(dp{sub sp})pi{sup 0} reactions showed that events from different positions of the extended target can be clearly identified in the ANKE detector system. The polarization of the atomic beam of the ABS, positioned close to the strong dipole magnet D2 of ANKE, was tuned with a Lamb-shift polarimeter (LSP) beneath the target chamber. With use of the known analyzing powers of the quasi-free np->dpi{sup 0} reaction, the polarization in the storage cell was measured to be Q{sub y} = 0.79+-0.07 in the vertical stray field of the D2 magnet acting as a holding field. The target thickness achieved was 2x10{sup 13} atoms/cm{sup 2} for one hyperfine state populated in the ABS beam only. With a COSY beam intensity of 6x10{sup 9} stored polarized deuterons in the ring, the luminosity for double polarized experiments was 1x10{sup 29} cm{sup -2} s{sup -1}.

  6. First Experiments with the Polarized Internal Gas Target (PIT) at ANKE/COSY

    SciTech Connect

    Engels, R.; Lorentz, B.; Prasuhn, D.; Rathmann, F.; Sarkadi, J.; Schleichert, R.; Seyfarth, H.; Stroeher, H.; Chiladze, D.; Dymov, S.; Grigoryev, K.; Mikirtychyants, M.; Kacharava, A.; Klehr, F.; Mikirtychyants, S.; Vasilyev, A.; Schieck, H. Paetz gen.; Steffens, E.

    2008-02-06

    For future few-nucleon interaction studies with polarized beams and targets at COSY-Juelich, a polarized internal storage-cell gas target was implemented at the magnet spectrometer ANKE in summer 2005. First commissioning of the polarized Atomic Beam Source (ABS) at ANKE was carried out and some improvements of the system have been done. Storage-cell tests to determine the COSY beam dimensions have been performed. Electron cooling combined with stacking and stochastic cooling have been studied. Experiments with N{sub 2} gas in the storage cell to simulate the background produced by beam interaction with the aluminum cell walls were performed to investigate the beam heating by the target gas. The analysis of the d-vector p-vector {yields}dp and d-vector p-vector{yields}(dp{sub sp}){pi}{sup 0} reactions showed that events from the extended target can be clearly identified in the ANKE detector system.The polarization of the atomic beam of the ABS, positioned close to the strong dipole magnet D2 of ANKE, was tuned with a Lamb-shift polarimeter (LSP) beneath the target chamber. With use of the known analyzing powers of the quasi-free np{yields}d{pi}{sup 0} reaction, the polarization in the storage cell was measured to be Q{sub y} = 0.79{+-}0.07 in the vertical stray field of the D2 magnet acting as a holding field. The achieved target thickness was 2x10{sup 13} atoms/cm{sup 2} for one hyperfine state populated in the ABS beam only. With a COSY beam intensity of 6x10{sup 9} stored polarized deuterons in the ring, the luminosity for double polarized experiments was 1x10{sup 29} cm{sup -2} s{sup -1}.

  7. Fracture toughness tests for particulate MMC UK COSI (IACFA) task group. Meeting report, October 1992

    NASA Astrophysics Data System (ADS)

    Roebuck, B.; Lord, J. D.

    1993-04-01

    Issues related to fracture toughness tests for particulate reinforced Metal Matrix Composites (MMC) debated at the second meeting of a UK COSI (United Kingdom Committee On Structural Integrity, formerly IACFA) task group, including contacts with BSI (British Standards Institute), residual stress measurements, plane strain toughness tests, Charpy impact tests, short bar chevron notch testing and crack length measurement methods are discussed. It was agreed that the main item on the agenda for the next meeting would be to reach an agreement on a recommended test method for toughness testing of particulate MMC.

  8. Structural Characterization and Thermoelectric Properties of Hot-Pressed CoSi Nanocomposites

    NASA Astrophysics Data System (ADS)

    Ioannou, Maria; Symeou, Elli; Giapintzakis, John; Kyratsi, Theodora

    2014-10-01

    Fabrication of nanocomposites by introduction of SiO2 metal oxide nanoparticles into a cobalt silicide thermoelectric matrix is studied. The CoSi matrix material was prepared through solid-state synthesis, and the nano-SiO2 metal oxide was introduced by mechanical grinding. The mixed powders were hot pressed to fabricate nanocomposites. The structural and morphological modifications were studied by powder x-ray diffraction analysis and scanning electron microscopy. The thermoelectric properties of the materials were followed through the Hall effect, Seebeck coefficient, and electrical and thermal conductivities in the temperature range from 300 K to 1000 K.

  9. Magnetic ordering in Sc2CoSi2-type R2FeSi2 (R=Gd, Tb) and R2CoSi2 (R=Y, Gd-Er) compounds

    NASA Astrophysics Data System (ADS)

    Morozkin, A. V.; Knotko, A. V.; Yapaskurt, V. O.; Pani, M.; Nirmala, R.; Quezado, S.; Malik, S. K.

    2016-09-01

    Magnetic and magnetocaloric properties of Sc2CoSi2-type R2TSi2 (R=Gd-Er, T=Fe, Co) compounds have been studied using magnetization data. These indicate the presence of mixed ferromagnetic and antiferromagnetic interactions in these compounds. One observes a ferromagnetic transition followed by an antiferromagnetic order and a further possible spin-reorientation transition at low temperatures. Compared to Gd2{Fe, Co}Si2, the Tb2FeSi2 and {Tb-Er}2CoSi2 compounds exhibit remarkable hysteresis (for e.g. Tb2FeSi2 shows residual magnetization Mres/Tb=2.45 μB, coercive field Hcoer=14.9 kOe, and critical field Hcrit 5 kOe at 5 K) possibly due to the magnetocrystalline anisotropy of the rare earth. The R2{Fe, Co}Si2 show relatively small magnetocaloric effect (i.e. isothermal magnetic entropy change, ΔSm) around the magnetic transition temperature: the maximal value of MCE is demonstrated by Ho2CoSi2 (ΔSm=-8.1 J/kg K at 72 K and ΔSm=-9.4 J/kg K at 23 K in field change of 50 kOe) and Er2CoSi2 (ΔSm=-13.6 J/kg K at 32 K and ΔSm=-8.4 J/kg K at 12 K in field change of 50 kOe).

  10. From CELSIUS to COSY: on the observation of a dibaryon resonance

    NASA Astrophysics Data System (ADS)

    Clement, H.; Bashkanov, M.; Skorodko, T.

    2015-11-01

    Using a high-quality beam of storage rings in combination with a pellet target and a hermetic WASA detector covering practically the full solid angle, two-pion production in nucleon-nucleon collisions has been systematically studied by exclusive and kinematically complete measurements—first at CELSIUS and subsequently at COSY. These measurements resulted in a detailed understanding of the two-pion production mechanism by t-channel meson exchange. The investigation of the ABC effect, which denotes an unusual low-mass enhancement in the ππ-invariant mass spectrum, in double-pionic fusion reactions led the trace to the observation of a narrow dibaryon resonance with I({J}P)=0({3}+) about 80 MeV below the nominal mass of the conventional Δ Δ system. New neutron-proton scattering data, taken with a polarized beam at COSY, produced a pole in the coupled {}3{D}3-3{G}3 partial waves at (2380+/- 10\\-\\i\\40+/- 5) MeV, establishing thus the first observation of a genuine s-channel dibaryon resonance.

  11. Kaon pair production in pp, pd and dd collisions at COSY

    SciTech Connect

    Hartmann, M.; Dzyuba, A.; Keshelashvili, I.; Maeda, Y.; Polyanskiy, A.; Wilkin, C.; Yuan, X.

    2010-08-05

    The near-threshold production of kaon-pairs has been investigated in proton-proton, proton-deuteron and deuteron-deuteron collisions at the Cooler Synchrotron COSY. The excitation function for the pp{yields}ppK{sup +}K{sup -} reaction and the invariant K{sup -}p, K{sup -}pp, and K{sup +}K{sup -} mass distributions indicate the presence of both K{sup -}p and K{sup +}K{sup -} final state interactions. Analogous final-state interactions of antikaons with deuterons has been found in the pp{yields}dK{sup +}K{sup 0}-bar reaction as well as in the pn{yields}dK{sup +}K{sup -} reaction, measured in the quasi-free pd{yields}p{sub sp}dK{sup +}K{sup -} process with a 'spectator' proton (p{sub sp}). The existing COSY data on the pd{yields}{sup 3}HeK{sup +}K{sup -} reaction are not yet sufficient to study the K{sup -3}He and K{sup +}K{sup -} final state interactions. A very small total cross section was found for the dd{yields}{sup 4}HeK{sup +}K{sup -} reaction.

  12. Signs of deuteron quadrupole coupling constants from COSY-2D spectra of solids

    NASA Astrophysics Data System (ADS)

    Schlemmer, H.; Haeberlen, U.

    It is shown how the signs of the quadrupole coupling constants (QCCs) of deuterons can be determined from the multiplet structures of the cross peaks in COSY-2D spectra of deuterons in molecular crystals or any other ordered sample. Multiplets arise as a result of dipolar couplings between pairs of deuterons. The 21) multiplet of a cross peak of a dipolar-coupled pair of deuterons consists of a 3 × 3 array of component lines. If the mixing pulse of the COSY sequence is a 90° pulse the multiplet is insensitive to the signs of the deuteron QCCs. If, however, the mixing pulse is a 54°44' pulse only four of the nine components are strong. These are located in one of the four corners of the 3 × 3 array. In which comer of the 3 × 3 array the four strong peaks appear depends on the relative signs of the dipolar and quadrupolar splittings D, ΔωQ1 and ΔωQ2. This can be used as a fingerprint for the relative signs of D, D, ΔωQ1 and ΔωQ2. The experimental conditions of the procedure are explored in an experiment on a single crystal of fully deuterated potassium oxalate monohydrate.

  13. Experimental Setup for Spin-Filtering Studies at Cosy and AD

    NASA Astrophysics Data System (ADS)

    Nass, A.

    2011-01-01

    The high physics potential of experiments with stored high-energy polarized antiprotons led to the proposal of PAX (Polarized Antiproton eXperiment) for the High Energy Storage Ring (HESR) of the new FAIR facility at GSI (Darmstadt/Germany). It is proposed to polarize a stored antiproton beam by means of spin-filtering with a polarized hydrogen (deuterium) gas target. The feasibility of spin-filtering with protons has been demonstrated in the FILTEX experiment. In an additional {ěc ebar p} depolarization experiment at COSY no influence of electron scattering on the proton polarization was found. Several experimental studies with protons (at COSY/Jülich) as well as antiprotons (at AD/CERN) will be carried out to measure spin-dependent {bar pěc p} and {bar pěc d} cross sections. A Polarized Internal gas Target (PIT) surrounded by silicon detectors and immersed into a low-β section has to be set up.

  14. CosI: Development of a low threshold detector for the observation of coherent elastic neutrino-nucleus scattering

    NASA Astrophysics Data System (ADS)

    Fields, Nicole Elizabeth

    I present the development of an experimental setup designed to measure CENNS (coherent elastic neutrino-nucleus scattering), a process that has never been experimentally observed. CosI (Coherent Neutrino Scattering with Cesium Iodide) uses a sodium doped cesium iodide detector intended to be able to observe CENNS at the SNS (Spallation Neutron Source) in Oak Ridge, TN. This thesis describes the experimental design and construction of the CosI apparatus, while sited at the University of Chicago. This thesis also presents the screening of materials for radioactivity in conjunction with simulations of the background contributions from various experimental components to CosI. Background measurements were performed at the University of Chicago with a 2 kg prototype CosI crystal, and those results are presented here. I also present neutrino signal calculations for the full size 15 kg CosI crystal which is to be installed at the SNS. Finally, the feasibility of a CENNS detection at the SNS using the CosI apparatus is discussed. This thesis also makes a contribution to the ongoing search for WIMP (weakly interacting massive particle) dark matter. I present a data-driven method for applying a surface event correction to CoGeNT (Coherent Germanium Neutrino Technology) data. After applying this correction, I then calculate new dark matter limits using the 807 day CoGeNT data set. In addition, I also perform a two dimensional maximum likelihood analysis of low energy CDMS (Cryogenic Dark Matter Search) data. The maximum likelihood analysis reveals a strong preference for a population of nuclear recoil events in the CDMS data set.

  15. Synthesis, characterization and magnetism of novel Cobalt-åkermanite:Ca2CoSi2O7

    NASA Astrophysics Data System (ADS)

    Barbar, Shiv Kumar; Patel, K. R.; Roy, M.; Sharma, R.; Kumar, Sudhish

    2017-04-01

    Polycrystalline sample of novel Cobalt-åkermanite: Ca2CoSi2O7 was synthesized using solid state reaction method. Room temperature powder X-ray diffraction and dc-electrical conductivity studies confirmed good quality of the synthesized sample in single phase tetragonal structure with space group: P 4 ̅21m. Low value of activation energy estimated from the dc-conductivity study indicates insulating behavior of this compound. Magnetic study showed a paramagnetic nature of Ca2CoSi2O7 at room temperature and antiferromagnetic nature below TN=5.6 K. In this compound weak ferromagnetism co-exist with antiferromagnetism below Neel temperature. Ca2CoSi2O7 displays magnetic field induced weak ferromagnetic transition around 7.4 K. Antiferromagnetic interactions occurs between the nearest neighbor Co2+ ions, as indicated by the negative sign of Weiss constant, θP=-22.7 K. Estimated value of the effective magnetic moment, μeff=4.75μB is found to be larger than the spin-only value of magnetic moment of Co2+ ion in the tetrahedral coordination having three unpaired electrons. These results, suggest that the orbital contribution to magnetic moment in this compound cannot be neglected and the electric polarization through spin dependent p-d hybridization can be expected in Ca2CoSi2O7.

  16. CoSi: Correlation of signals-A new measure to assess the correlation of history response curves

    NASA Astrophysics Data System (ADS)

    Murmann, Robert; Harzheim, Lothar; Dominico, Stefan; Immel, Rainer

    2016-12-01

    In the context of CAE work it is often required to assess the level of agreement of two curves objectively, e.g. measured against numerically computed results. Therefore a new comprehensive measure is proposed in this paper. The new measure 'CoSi' (Correlation of Signals) allows to account for uncertainties in both curves. This is achieved by constructing a corridor around one curve which considers deviations in direction of both abscissa and ordinate. Here CoSi differs from other common corridor approaches which consider only the deviation on the ordinate. It is explained how CoSi aligns the two curves taking the uncertainties of the second curve by scaling and shifting into account. This leads to the best theoretical achievable agreement between the two curves. Based on the aligned curves, quality factors are calculated to evaluate the results in terms of amplitudes of the curves, their overall match in shape, the phase between the curves, and all these combined into a comprehensive quality factor. The properties and results of CoSi are compared with other metrics from literature using various examples.

  17. COSY Simulations to Guide Commissioning of the St. George Recoil Mass Separator

    NASA Astrophysics Data System (ADS)

    Schmitt, Jaclyn; Moran, Michael; Seymour, Christopher; Gilardy, Gwenaelle; Meisel, Zach; Couder, Manoel

    2015-10-01

    The goal of St. George (STrong Gradient Electromagnetic Online Recoil separator for capture Gamma ray Experiments) is to measure (α, γ) cross sections relevant to stellar helium burning. Recoil separators such as St. George are able to more closely approach the low astrophysical energies of interest because they collect reaction recoils rather than γ-rays, and thus are not limited by room background. In order to obtain an accurate cross section measurement, a recoil separator must be able to collect all recoils over their full range of expected energy and angular spread. The energy acceptance of St. George is currently being measured, and the angular acceptance will be measured soon. Here we present the results of COSY ion optics simulations and magnetic field analyses which were performed to help guide the commissioning measurements and diagnostic upgrades required to complete those measurements. National Science Foundation Research Experiences for Undergraduates program.

  18. Nucleon-nucleon scattering at small angles, measured at ANKE-COSY

    NASA Astrophysics Data System (ADS)

    Bagdasarian, Z.

    2016-03-01

    The most accepted approach to describe nucleon-nucleon (NN) interaction is the partial wave analysis (PWA), which translates various experimental observables to the common language of the partial waves. The reliable analysis relies not only on the quality experimental data, but also on the measurements of scattering observables over preferably the full angular range. Small angle scattering has been measured for six beam energies between 0.8 and 2.4 GeV using polarized proton beam incident on both proton and deuteron unpolarized targets at COSY-ANKE. This proceeding will report on the published and preliminary results for both pp and pn scattering from this and other recent experiments at ANKE. This study aims to provide the valuable observables to the SAID group in order to improve the phenomenological understanding of the nucleon-nucleon interaction.

  19. Searching for η-mesic Helium with WASA-at-COSY facility

    NASA Astrophysics Data System (ADS)

    Rundel, Oleksandr; Khreptak, Oleksandr; Skurzok, Magdalena; Krzemien, Wojciech; Moskal, Pawel

    2016-11-01

    The search for the 4He-η and 3He-η bound states was performed with the WASA-at-COSY facility using a ramped beam technique in 2008, 2010 and 2014, respectively. The 2008 and 2010 data analyses has already been completed and resulted in the upper limits for the total cross sections for the η-mesic 4He production in dd → 3Henπ0 and dd → 3Hepπ- processes. No narrow structure which could be interpreted as a bound state was observed. The experiment carried out in 2014 collected the largest data sample for 3He-η in the world. The data analysis is in progress. This article presents results of the 2010 data analysis and preliminary results of the 2014 data analysis.

  20. Initial Research of np Scattering with Polarized Deuterium Target at ANKE/COSY

    NASA Astrophysics Data System (ADS)

    Gou, B.

    2016-02-01

    The quasi-free np charge-exchange reaction pd→ →{pp}sn has to be employed to extend the investigations of np scattering at ANKE to the highest energy available at COSY. As the proof-of-principle experiment, the initial research has been conducted at proton energy Tp = 600 MeV using a polarized Deuterium target. The vector and tensor analyzing powers Ay and Ayy were measured for momentum transfers q ⩾ 160 MeV/c. These data connect smoothly with the previous measurements at q ⩽ 140 MeV/c performed using a polarized deuteron beam. The reported data are well reproduced by the impulse approximation using the SAID np amplitudes. The results therefore proves that it is possible to continue the np programme at higher energies at ANKE.

  1. Constituents from the stem barks of Canarium bengalense with cytoprotective activity against hydrogen peroxide-induced hepatotoxicity.

    PubMed

    Le, Hoang Thi; Ha, Do Thi; Minh, Chau Thi Anh; Kim, Tae Hoon; Van Kiem, Phan; Thuan, Nguyen Duy; Na, Minkyun

    2012-01-01

    Phytochemical investigation of the stem barks of Canarium bengalense (Burseraceace) resulted in the isolation of a new flavone glycoside (5) together with six known compounds (1-4, 6, and 7). The chemical structure of the new compound was elucidated as 3'-hydroxy-7,4'-dimethoxyflavone-5-O-α-L-arabinofuranosyl-(1→6)-β-D-glucopyranoside by means of 1D and 2D NMR ((1)H-(1)H COSY, HMQC, and HMBC) and MS analyses. To evaluate the in vitro cytoprotective effect, the isolates (1-7) were tested against hydrogen peroxide (H(2)O(2))-induced damage in primary cultured hepatocytes. The viability of hepatocytes was increased by treatment with each compound, except compound 1. Compounds 3, 4, and 7 exerted cytoprotective effects comparable to curcumin, the positive control. Our results suggest that the cytoprotective constituents of C. bengalense may contribute to its traditional use in the treatment of tumor and liver damage.

  2. Antioxidant activity of a new phenolic glycoside from Lagenaria siceraria Stand. fruits.

    PubMed

    Mohan, Rahul; Birari, Rahul; Karmase, Aniket; Jagtap, Sneha; Bhutani, Kamlesh Kumar

    2012-05-01

    The antioxidant properties of different extracts of Lagenaria siceraria (bottle gourd) fruit were evaluated. In the process, a new phenolic glycoside (E)-4-hydroxymethyl-phenyl-6-O-caffeoyl-β-d-glucopyranoside (1) was isolated and identified together with 1-(2-hydroxy-4-hydroxymethyl)-phenyl-6-O-caffeoyl-β-d-gluco-pyranoside (2), protocatechuic acid (3), gallic acid (4), caffeic acid (5) and 3,4-dimethoxy cinnamic acid (6). Their structures were elucidated by extensive NMR experiments including (1)H-(1)H (COSY) and (1)H-(13)C (HMQC and HMBC) spectroscopy and chemical evidences. The antioxidant potential of the compound 1 and 2 was tested in different in vitro assay systems such as free radical scavenging assay, 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay, superoxide scavenging activity, reducing power assay and linoleic acid peroxidation assay. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Diterpenes from the Trunk of Abies holophylla and Their Potential Neuroprotective and Anti-inflammatory Activities.

    PubMed

    Kim, Chung Sub; Subedi, Lalita; Kim, Sun Yeou; Choi, Sang Un; Kim, Ki Hyun; Lee, Kang Ro

    2016-02-26

    Eleven new abietane-type diterpenes, holophyllins D-N (1-11), and 17 known analogues (12-28), were isolated from a MeOH extract of the trunk of Abies holophylla. The chemical structures of 1-11 were determined through spectroscopic data analysis, including NMR ((1)H and (13)C NMR, DEPT, (1)H-(1)H COSY, HMQC, HMBC, and NOESY) and HRFABMS methods. All isolated compounds (1-28) were evaluated for their cytotoxicity against four human tumor cell lines (A549, SK-OV-3, SK-MEL-2, and HCT-116), for their potential neuroprotective effects through induction of nerve growth factor in C6 glioma cells, and for their effects on nitric oxide levels in lipopolysaccharide-stimulated murine microglia BV2 cells.

  4. Gelsedine-type oxindole alkaloids from Gelsemium elegans and the evaluation of their cytotoxic activity.

    PubMed

    Wang, Lei; Wang, Jin-Feng; Mao, Xia; Jiao, Li; Wang, Xiao-Jun

    2017-07-01

    Phytochemical investigation on the 70% EtOH extract of the leaves and branches of Gelsemium elegans resulted into the isolation of five new gelsedine-type oxindole alkaloids, gelseleganins A-E (1-5). The structures of the isolated compounds were established based on 1D and 2D ((1)H-(1)H COSY, HMQC, and HMBC) NMR spectroscopy, in addition to high resolution mass spectrometry. The isolated alkaloids were tested in vitro for cytotoxic potential against seven tumor cell lines. As a result, alkaloids 3 exhibited significant cytotoxic activities against all the tested tumor cell lines with IC50 values <10μM. Copyright © 2017. Published by Elsevier B.V.

  5. Steroidal Saponins from the Rhizomes of Aspidistra typica

    PubMed Central

    Zhao, Yang; Zhao, Jian-Yuan; Zhang, Jie; Pang, Xu; Yu, He-Shui; Jia, De-Xian; Liu, Chao; Yu, Li-Yan; Ma, Bai-Ping

    2016-01-01

    Eleven new furostanol saponins, typaspidosides B-L (1–11), one new spirostanol saponin, typaspidoside M (12), and five known spirostanol saponins, 25S-atropuroside (13), neoaspidistrin (14), (25S)-pratioside D1 (15), 25S-aspidistrin (16) and 25S-neosibiricoside (17) were isolated from the rhizomes of Aspidistra typica Baill. The structures of the new compounds were established using 1D and 2D NMR (1H-1H COSY, HMQC, HMBC and ROESY) spectroscopy, high resolution mass spectrometry, and chemical methods. The aglycones of 1–3 (unusual furostanol saponins with opened E ring type), 9 and 10 (the methoxyl substituent at C-23 position) were found, identified from natural products for the first time. Moreover, the anti-HIV activities of the isolated steroidal glycosides were assessed, and compounds 13, 14, 16 and 17 exhibited high active against HIV-1. PMID:26937954

  6. Structure of the acidic O-specific polysaccharide from Proteus vulgaris O39 containing 5,7-diacetamido-3,5,7,9-tetradeoxy-L-glycero-L-manno-non-2-ulosonic acid.

    PubMed

    Kondakova, A N; Perepelov, A V; Bartodziejska, B; Shashkov, A S; Senchenkova, S N; Wykrota, M; Knirel, Y A; Rozalski, A

    2001-07-12

    The O-specific polysaccharide of Proteus vulgaris O39 was found to contain a new acidic component of Proteus lipopolysaccharides, 5,7-diacetamido-3,5,7,9-tetradeoxy-L-glycero-L-manno-non-2-ulosonic acid (di-N-acetylpseudaminic acid, Pse5Ac7Ac). The following structure of the polysaccharide was determined by NMR spectroscopy, including 2D 1H,(1)H COSY, TOCSY, ROESY, and 1H,(13)C HMQC experiments, along with selective cleavage of the polysaccharide by solvolysis with anhydrous trifluoromethanesulfonic (triflic) acid: -->8)-beta-Psep5Ac7Ac-(2-->3)-alpha-L-FucpNAc-(1-->3)-alpha-D-GlcpNAc-(1--> The structure established is unique among the O-specific polysaccharides, which is in accordance with classification of the strain studied into a separate Proteus serogroup.

  7. Molecular-level insights into the oxidative degradation of grafted amines.

    PubMed

    Ahmadalinezhad, Asieh; Tailor, Ritesh; Sayari, Abdelhamid

    2013-08-05

    The oxidative degradation of CO2 adsorbents consisting of amine-grafted pore-expanded mesoporous MCM-41 silica was investigated. The adsorbents were treated under flowing air at various temperatures, and the degree of deactivation was evaluated through the measurement of their CO2 adsorption capacity prior and subsequent to exposure to air. To decipher the chemical structure of surface species upon air-deactivation of grafted amines, a solvent extraction procedure was developed using a deuterated basic solution. The obtained solutions were analyzed by a variety of 1D and 2D NMR spectroscopy techniques, such as (29)Si, (13)C, (1)H, [(1)H,(15)N] HMBC, [(1)H,(13)C] HMQC, COSY and DOSY. The surface species generated by oxidative degradation of amine-grafted silica were found to contain functional groups such as imine, amide and carboxylic groups. Several structural units were conclusively demonstrated.

  8. Induction of quinone reductase (QR) by withanolides isolated from Physalis angulata L. var. villosa Bonati (Solanaceae).

    PubMed

    Ding, Hui; Hu, Zhijuan; Yu, Liyan; Ma, Zhongjun; Ma, Xiaoqiong; Chen, Zhe; Wang, Dan; Zhao, Xiaofeng

    2014-08-01

    In the present study, the EtOAc extract of the persistent calyx of Physalis angulata L. var. villosa Bonati (PA) was tested for its potential quinone reductase (QR) inducing activity with glutathione (GSH) as the substrate using an UPLC-ESI-MS method. The result revealed that the PA had electrophiles that could induce quinone reductase (QR) activity, which might be attributed to the modification of the highly reactive cysteine residues in Keap1. Herein, three new withanolides, compounds 3, 6 and 7, together with four known withanolides, compounds 1, 2, 4 and 5 were isolated from PA extract. Their structures were determined by spectroscopic techniques, including (1)H-, (13)C NMR (DEPT), and 2D-NMR (HMBC, HMQC, (1)H, (1)H-COSY, NOESY) experiments, as well as by HR-MS. All the seven compounds were tested for their QR induction activities towards mouse hepa 1c1c7 cells.

  9. Cytotoxic withanolides from Physalis angulata L.

    PubMed

    He, Qing-Ping; Ma, Lei; Luo, Jie-Ying; He, Fu-Yuan; Lou, Li-Guang; Hu, Li-Hong

    2007-03-01

    Four new withanolides, physagulins L-O (1-4), were isolated from the MeOH extract of the aerial parts of Physalis angulata L. (Solanaceae), together with seven known withanolides, compounds 5-11. Their structures were determined by spectroscopic techniques, including 1H-, 13C-NMR (DEPT), and 2D-NMR (HMBC, HMQC, 1H,1H-COSY, NOESY) experiments, as well as by HR-MS. All eleven compounds were tested for their antiproliferative activities towards human colorectal-carcinoma (HCT-116) and human non-small-cell lung-cancer (NCI-H460) cells. Compound 5 exhibited the highest anticancer activity against the HCT-116 cell line, with an IC50 value of 1.64+/-0.06 microM. Compound 9 exhibited the highest cytotoxicity towards the NCI-H460 cell line, with an IC50 value of 0.43+/-0.02 microM.

  10. Structure elucidation of organic compounds from natural sources using 1D and 2D NMR techniques

    NASA Astrophysics Data System (ADS)

    Topcu, Gulacti; Ulubelen, Ayhan

    2007-05-01

    In our continuing studies on Lamiaceae family plants including Salvia, Teucrium, Ajuga, Sideritis, Nepeta and Lavandula growing in Anatolia, many terpenoids, consisting of over 50 distinct triterpenoids and steroids, and over 200 diterpenoids, several sesterterpenoids and sesquiterpenoids along with many flavonoids and other phenolic compounds have been isolated. For Salvia species abietanes, for Teucrium and Ajuga species neo-clerodanes for Sideritis species ent-kaurane diterpenes are characteristic while nepetalactones are specific for Nepeta species. In this review article, only some interesting and different type of skeleton having constituents, namely rearranged, nor- or rare diterpenes, isolated from these species will be presented. For structure elucidation of these natural diterpenoids intensive one- and two-dimensional NMR techniques ( 1H, 13C, APT, DEPT, NOE/NOESY, 1H- 1H COSY, HETCOR, COLOC, HMQC/HSQC, HMBC, SINEPT) were used besides mass and some other spectroscopic methods.

  11. A new ribonucleotide from Cordyceps militaris.

    PubMed

    Sun, Jinfeng; Jin, Mei; Zhou, Wei; Diao, Shengbao; Zhou, Yi; Li, Shuaishuai; Wang, Xin; Pan, Shuai; Jin, Xuejun; Li, Gao

    2017-11-01

    One new ribonucleotide, 5'-(3''-deoxy-β-D-ribofuranosyl)-3'-deoxyadenosine (1), and 14 known compounds (2-15) were isolated from an ethanol extract of Cordyceps militaris. The chemical structures of these compounds were determined from 1D and 2D NMR ((1)H-(1)H COSY, HMBC, HMQC and NOESY) and HR-ESI-MS spectra, and results were compared with data from the literature. The effects of all isolated compounds were measured on NF-κB activation, with compound 2 exhibiting significant inhibitory activity against TNF-α-induced NF-κB reporter gene expression in HeLa cells from 3 to 100 μM.

  12. Metal-mediated coupling of a coordinated isocyanide and indazoles.

    PubMed

    Kinzhalov, Mikhail A; Boyarskiy, Vadim P; Luzyanin, Konstantin V; Dolgushin, Fedor M; Kukushkin, Vadim Yu

    2013-08-07

    A reaction between equimolar amounts of cis-[PdCl2(CNCy)2] (1) and indazole (HInd, 2) or 5-methylindazole (HInd(Me), 3) proceeded in refluxing CHCl3 for ca. 6 h affording the aminocarbene species cis-[PdCl2{C(Ind)=N(H)Cy}(CNCy)] (4) or cis-[PdCl2{C(Ind(Me))=N(H)Cy}(CNCy)] (5) in good (72-83%) isolated yields. Complexes 4 and 5 were characterized by elemental analyses (C, H, N), HR ESI(+)-MS, IR, and 1D ((1)H, (13)C{(1)H}) and 2D ((1)H,(1)H-COSY, (1)H,(13)C-HMQC/(1)H,(13)C-HSQC, (1)H,(13)C-HMBC) NMR spectroscopies, and complex 4 as well by X-ray diffraction. The observed coupling represents the first example of metal-mediated integration between any isocyanide and any aromatic heterocyclic system having an HN center.

  13. Isolation of an alpha-methylene-gamma-butyrolactone derivative, a toxin from the plant pathogen Lasiodiplodia theobromae.

    PubMed

    He, Guochun; Matsuura, Hideyuki; Yoshihara, Teruhiko

    2004-10-01

    Lasiodiplodia theobromae is known as a multi-infectious microorganism that causes considerable crop damage, particularly to tropical fruits. When the fruits are infected by L. theobromae, the typical symptom is the appearance of black spots on the surface of the infected fruit. When injected in to the peel of banana, the culture filtrate of L. theobromae induced formation of black spots. The structure of the isolated compound responsible for this effect was determined to be (3S,4R)-3-carboxy-2-methylene-heptan-4-olide on the basis of analysis of MS, IR, and 1H and 13C NMR spectroscopic data, including HMQC, HMBC, and 1H-1H COSY experiments. The active compound was not only isolated from the culture filtrate derived from potato dextrose medium, but also from the extract of infected peels of bananas.

  14. Salvianolic acid Y: a new protector of PC12 cells against hydrogen peroxide-induced injury from Salvia officinalis.

    PubMed

    Gong, Jun; Ju, Aichun; Zhou, Dazheng; Li, Dekun; Zhou, Wei; Geng, Wanli; Li, Bing; Li, Li; Liu, Yanjie; He, Ying; Song, Meizhen; Wang, Yunhua; Ye, Zhengliang; Lin, Ruichao

    2015-01-06

    Salvianolic acid Y (TSL 1), a new phenolic acid with the same planar structure as salvianolic acid B, was isolated from Salvia officinalis. The structural elucidation and stereochemistry determination were achieved by spectroscopic and chemical methods, including 1D, 2D-NMR (1H-1H COSY, HMQC and HMBC) and circular dichroism (CD) experiments. The biosynthesis pathway of salvianolic acid B and salvianolic acid Y (TSL 1) was proposed based on structural analysis. The protection of PC12 cells from injury induced by H2O2 was assessed in vitro using a cell viability assay. Salvianolic acid Y (TSL 1) protected cells from injury by 54.2%, which was significantly higher than salvianolic acid B (35.2%).

  15. Isolation and characterization of water-soluble intermediates of blue pigments transformed from geniposide of Gardenia jasminoides.

    PubMed

    Park, Jee-Eun; Lee, Jae-Youn; Kim, Hong-Gyu; Hahn, Tae-Ryong; Paik, Young-Sook

    2002-10-23

    Gardenia blue dye was obtained through the reaction of methylamine with genipin, the aglycone of geniposide isolated from the fruits of Gardenia jasminoides. The resulting blue pigments were passed through Bio-Gel P-2 resin yielding five fractions, GM1-GM5. Four fractions (GM1-GM4) were all blue pigments, and the first eluted higher molecular weight fraction GM1 had a higher tinctorial strength than the later eluted lower molecular weight fractions, GM2-GM4. The last eluted GM5 fraction with lambda(max) of 292 nm was colorless and was confirmed as the true intermediate of the blue pigments on the basis of UV-vis spectrophotometric evidence. The GM5 fraction was composed of two epimeric isomers, and their structures were characterized by (1)H NMR, (1)H-(1)H COSY, (13)C NMR, and HMQC and HMBC spectral measurements.

  16. New Antifungal Pyranoisoflavone from Ficus tikoua Bur.

    PubMed Central

    Wei, Shaopeng; Wu, Wenjun; Ji, Zhiqin

    2012-01-01

    Considering the undesirable attributes of synthetic fungicides and the availability of Ficus species in China, the stem of Ficus tikoua Bur. was investigated. One new antifungal pyranoisoflavone, 5,3′,4′-trihydroxy-2″,2″-dimethylpyrano (5″,6″:7,8) isoflavone (1), together with two known isoflavones, wighteone (2) and lupiwighteone (3) (with previously reported antifungal activities), were isolated from ethyl acetate extract by bioassay-guided fractionation. Their structures were determined by spectroscopic analysis, such as NMR (1H-1H COSY, HMQC, HMBC and NOESY), IR, UV and HRMS, as well as ESI-MSn analyses. The antifungal activities of 1–3 against Phytophthora infestans were evaluated by direct spore germination assay, and the IC50 values were 262.442, 198.153 and 90.365 μg·mL−1, respectively. PMID:22837700

  17. The Composite Strain Index (COSI) and Cumulative Strain Index (CUSI): methodologies for quantifying biomechanical stressors for complex tasks and job rotation using the Revised Strain Index.

    PubMed

    Garg, Arun; Moore, J Steven; Kapellusch, Jay M

    2017-08-01

    The Composite Strain Index (COSI) quantifies biomechanical stressors for complex tasks consisting of exertions at different force levels and/or with different exertion times. The Cumulative Strain Index (CUSI) further integrates biomechanical stressors from different tasks to quantify exposure for the entire work shift. The paper provides methodologies to compute COSI and CUSI along with examples. Complex task simulation produced 169,214 distinct tasks. Use of average, time-weighted average (TWA) and peak force and COSI classified 66.9, 28.2, 100 and 38.9% of tasks as hazardous, respectively. For job rotation the simulation produced 10,920 distinct jobs. TWA COSI, peak task COSI and CUSI classified 36.5, 78.1 and 66.6% jobs as hazardous, respectively. The results suggest that the TWA approach systematically underestimates the biomechanical stressors and peak approach overestimates biomechanical stressors, both at the task and job level. It is believed that the COSI and CUSI partially address these underestimations and overestimations of biomechanical stressors. Practitioner Summary: COSI quantifies exposure when applied hand force and/or duration of that force changes during a task cycle. CUSI integrates physical exposures from job rotation. These should be valuable tools for designing and analysing tasks and job rotation to determine risk of musculoskeletal injuries.

  18. Using COSI-CORR to Quantify Earthflow Movement Rates Over Decadal Time Scales

    NASA Astrophysics Data System (ADS)

    Cerovski-Darriau, C.; Roering, J. J.

    2011-12-01

    Large, complex earthflow systems can evolve over diverse (seasonal to millennial) timescales and thus require a range of tools to document their kinematics. In many areas, extensive archives of historical aerial photographs offer potential for quantifying decadal fluctuations, but tracking individual features has been impractical over significant temporal and spatial scales. Here, we explore recent software that automates landslide mapping and improves feasibility of tracking deformation at these scales. The Co-registration of Optically Sensed Images and Correlation (COSI-Corr) software allows for correlation between air photographs and LiDAR imagery, and tracks surface deformation over a sequence of aerial surveys. To analyze the efficacy for landslides, we focused on a 1km2 area riddled with active earthflows, shallow landslides, and gullying in the Waipaoa River catchment on the North Island of New Zealand. This area is dominated by Late Cretaceous-Early Tertiary clay-rich mudstones and calcite-rich sandstones with highly sheared and more massive units that fail in diverse fashion. Starting in the 1900s, the area was burned and converted to pastureland, and is now heavily grazed by sheep and cattle. Slope deformation in the study area has accelerated due to this history of land use changes. We used aerial photographs from 1956, 1960, 1979, and 1982 to track slide movement. The photos were scanned at 1200 dpi (21 micron), giving a ground resolution between approximately 0.2-1m/pixel (scale of 1:16000 to 1:47000). We rectified the photos with 2010 orthophotos and a corresponding 1m LiDAR DEM and hillshade map using the COSI-Corr interface in ENVI 4.5. They were then sequentially correlated, which automatically identifies surface changes with sub-pixel resolution. Next we generated a vector field displacement map for each time step with 8m grid nodes. The resulting vector maps show velocities ranging from about 1-5m/yr. This corresponds well with previously

  19. Negative differential resistance of metal (CoSi2)/insulator (CaF2) triple-barrier resonant tunneling diode

    NASA Astrophysics Data System (ADS)

    Watanabe, Masahiro; Suemasu, Takashi; Muratake, Shigeki; Asada, Masahiro

    1993-01-01

    The electron transport and negative differential resistance in metal-insulator nanometer-thick heterostructures are reported for the first time. The structure of the samples is a resonant tunneling diode with three-barriers of 0.9-nm-thick CaF2 layers and two wells of 1.9- and 2.8-nm-thick CoSi2 layers. These layers were grown by means of partially ionized beam epitaxy for CaF2 and a two step growth technique for CoSi2. In the current-voltage characteristics at 77 K, negative differential resistance was observed in the significant number of samples and the typical peak-to-valley ratio was as high as 2. The negative differential resistance observed here can be attributed to the electron transport through the resonant levels in metal/insulator multilayered heterostructures.

  20. Fabrication and electrical transport properties of binary Co-Si nanostructures prepared by focused electron beam-induced deposition

    NASA Astrophysics Data System (ADS)

    Porrati, F.; Kämpken, B.; Terfort, A.; Huth, M.

    2013-02-01

    CoSi-C binary alloys have been fabricated by focused electron beam-induced deposition by the simultaneous use of dicobaltoctacarbonyl, Co2(CO)8, and neopentasilane, Si5H12, as precursor gases. By varying the relative flux of the precursors, alloys with variable chemical composition are obtained, as shown by energy dispersive x-ray analysis. Room temperature electrical resistivity measurements strongly indicate the formation of cobalt silicide and cobalt disilicide nanoclusters embedded in a carbonaceous matrix. Temperature-dependent electrical conductivity measurements show that the transport properties are governed by electron tunneling between neighboring CoSi or CoSi2 nanoclusters. In particular, by varying the metal content of the alloy, the electrical conductivity can be finely tuned from the insulating regime into the quasi-metallic tunneling coupling regime.

  1. Columnar growth of CoSi2 on Si(111), Si(100) and Si(110) by molecular beam epitaxy

    NASA Technical Reports Server (NTRS)

    Fathauer, R. W.; Nieh, C. W.; Xiao, Q. F.; Hashimoto, Shin

    1990-01-01

    Codeposition of silicon and cobalt on heated silicon substrates in ratios several times the silicide stoichiometry is found to result in epitaxial columns of CoSi2 surrounded by a matrix of epitaxial silicon. For (111)-oriented wafers, nearly cylindrical columns are formed, where both columns and surrounding silicon are defect free, as deduced from transmission electron microscopy. Independent control of the column diameter and separation is possible, and diameters of 27-135 nm have been demonstrated.

  2. Columnar growth of CoSi2 on Si(111), Si(100) and Si(110) by molecular beam epitaxy

    NASA Technical Reports Server (NTRS)

    Fathauer, R. W.; Nieh, C. W.; Xiao, Q. F.; Hashimoto, Shin

    1990-01-01

    Codeposition of silicon and cobalt on heated silicon substrates in ratios several times the silicide stoichiometry is found to result in epitaxial columns of CoSi2 surrounded by a matrix of epitaxial silicon. For (111)-oriented wafers, nearly cylindrical columns are formed, where both columns and surrounding silicon are defect free, as deduced from transmission electron microscopy. Independent control of the column diameter and separation is possible, and diameters of 27-135 nm have been demonstrated.

  3. A very light and thin liquid hydrogen/deuterium heat pipe target for COSY experiments

    NASA Astrophysics Data System (ADS)

    Abdel-Bary, M.; Abdel-Samad, S.; Kilian, K.

    2005-07-01

    A liquid hydrogen/deuterium heat pipe (HP) target is used at the COSY external experiments TOF, GEM and MOMO. The target liquid is produced at a cooled condenser and guided through a central tube assisted by gravitation into the target cell. An aluminum condenser is used instead of copper, which requires less material, improves conductivities and provides shorter cooling down time. Residual condenser temperature fluctuations in the order of ≈0.4 K are reduced by using thermal resistances between the cooling machine and the condenser of the heat pipe combined with a controlled heating power. A new design with only a 7-mm-diameter HP has been developed. The diameter of the condenser part remains at 16 mm to provide enough condensation area. The small amount of material ensures short cooling down times. A cold gas deuterium HP target has been designed and developed which allows protons with energy ⩽1 MeV to be measured. A 7-mm-diameter HP is used to fill a cooling jacket around the D 2 gas cell with LH 2. The D 2 gas is stabilized at 200 mbar to allow for thin windows. Its density is increased by factor 15 compared to room temperature.

  4. Effect of local atomic and electronic structures on thermoelectric properties of chemically substituted CoSi

    NASA Astrophysics Data System (ADS)

    Hsu, C. C.; Pao, C. W.; Chen, J. L.; Chen, C. L.; Dong, C. L.; Liu, Y. S.; Lee, J. F.; Chan, T. S.; Chang, C. L.; Kuo, Y. K.; Lue, C. S.

    2014-05-01

    We report the effects of Ge partial substitution for Si on local atomic and electronic structures of thermoelectric materials in binary compound cobalt monosilicides (\\text{CoSi}_{1-x}\\text{Ge}_{x}\\text{:}\\ 0 \\le x \\le 0.15 ). Correlations between local atomic/electronic structure and thermoelectric properties are investigated by means of X-ray absorption spectroscopy. The spectroscopic results indicate that as Ge is partially substituted onto Si sites at x \\le 0.05 , Co in CoSi1-xGex gains a certain amount of charge in its 3d orbitals. Contrarily, upon further replacing Si with Ge at x \\ge 0.05 , the Co 3d orbitals start to lose some of their charge. Notably, thermopower is strongly correlated with charge redistribution in the Co 3d orbital, and the observed charge transfer between Ge and Co is responsible for the variation of Co 3d occupancy number. In addition to Seebeck coefficient, which can be modified by tailoring the Co 3d states, local lattice disorder may also be beneficial in enhancing the thermoelectric properties. Extended X-ray absorption fine structure spectrum results further demonstrate that the lattice phonons can be enhanced by Ge doping, which results in the formation of the disordered Co-Co pair. Improvements in the thermoelectric properties are interpreted based on the variation of local atomic and electronic structure induced by lattice distortion through chemical substitution.

  5. Studies of the Twin Helix Parametric-resonance Ionization Cooling Channel with COSY INFINITY

    SciTech Connect

    J.A. Maloney, K.B. Beard, R.P. Johnson, A. Afanasev, S.A. Bogacz, Y.S. Derbenev, V.S. Morozov, B. Erdelyi

    2012-07-01

    A primary technical challenge to the design of a high luminosity muon collider is an effective beam cooling system. An epicyclic twin-helix channel utilizing parametric-resonance ionization cooling has been proposed for the final 6D cooling stage. A proposed design of this twin-helix channel is presented that utilizes correlated optics between the horizontal and vertical betatron periods to simultaneously focus transverse motion of the beam in both planes. Parametric resonance is induced in both planes via a system of helical quadrupole harmonics. Ionization cooling is achieved via periodically placed wedges of absorbing material, with intermittent rf cavities restoring longitudinal momentum necessary to maintain stable orbit of the beam. COSY INFINITY is utilized to simulate the theory at first order. The motion of particles around a hyperbolic fixed point is tracked. Comparison is made between the EPIC cooling channel and standard ionization cooling effects. Cooling effects are measured, after including stochastic effects, for both a single particle and a distribution of particles.

  6. Sputtering of NbSi 2 and CoSi 2

    NASA Astrophysics Data System (ADS)

    Hamdi, A. M.; Affolter, K.; Nicolet, M.-A.

    1985-03-01

    Sputtering of niobium and cobalt disilicide films on oxidized Si substrates interposed with an amorphous Si layer has been studied by backscattering spectrometry (BS). Thin NbSi 2 (600 Å) and CoSi 2 (370 Å) films were sputtered by Xe ions at energies of 200 and 260 keV, respectively. The sputtering process was carried out either at room temperature (RT), or at elevated temperatures, placing the samples in the radiation enhanced diffusion regime. The sputtering yields of Si, Ssi, and that of the metals, SNb or SCo, have been calculated from BS spectra. The measured ratios of the sputtering yields for both suicides, {S si}/{S Nb} and {S si}/{S Co}, imply that preferential sputtering of Si with respect to the stoichiometrical composition of these suicides had occurred. {S si}/{S Nb} is found to be about 13 and showed little change with dose and temperature. {S si}/{S Co} increased with both temperature or dose from about 4.3 for a dose of {5 × 10 16}/{cm 2} at RT to about 7.2 for {1 × 10 17}/{cm 2} at elevated temperature. These ratios are in contrast to that reported for CrSi 2 at high temperatures (i.e. {S si}/{S Cr} = 65 ). Possible reasons are thought to be related to the high affinity of Si to oxygen contamination.

  7. The control system of the polarized internal target of ANKE at COSY

    NASA Astrophysics Data System (ADS)

    Kleines, H.; Sarkadi, J.; Zwoll, K.; Engels, R.; Grigoryev, K.; Mikirtychyants, M.; Nekipelov, M.; Rathmann, F.; Seyfarth, H.; Kravtsov, P.; Vasilyev, A.

    2006-05-01

    The polarized internal target for the ANKE experiment at the Cooler Synchrotron COSY of the Forschungszentrum Jülich utilizes a polarized atomic beam source to feed a storage cell with polarized hydrogen or deuterium atoms. The nuclear polarization is measured with a Lamb-shift polarimeter. For common control of the two systems, industrial equipment was selected providing reliable, long-term support and remote control of the target as well as measurement and optimization of its operating parameters. The interlock system has been implemented on the basis of SIEMENS SIMATIC S7-300 family of programmable logic controllers. In order to unify the interfacing to the control computer, all front-end equipment is connected via the PROFIBUS DP fieldbus. The process control software was implemented using the Windows-based WinCC toolkit from SIEMENS. The variety of components, to be controlled, and the logical structure of the control and interlock system are described. Finally, a number of applications derived from the present development to other, new installations are briefly mentioned.

  8. Electromagnetic Transition Form Factor of the η meson with WASA-at-COSY

    NASA Astrophysics Data System (ADS)

    Goswami, A.

    2016-11-01

    In this work we present a study of the Dalitz decay η → γe+e-. The aim of this work is to measure the transition form factor of the η meson. The transition form factor of the η meson describes the electromagnetic structure of the meson. The study of the Dalitz decay helps to calculate the transition form factor of the η meson. When a particle is point-like it's decay rate can be calculated within QED. However, the complex structure of the meson modifies its decay rate. The transition form factor is determined by comparing the lepton-antilepton invariant mass distribution with QED. For this study data on proton-proton reaction at a beam energy of 1.4 GeV has been collected with WASA-at-COSY detector at Forschungszentrum Juelich, Germany. In the higher invariant mass region recent theoretical calculations slightly deviate from the fit to the data. We expect better results in the higher invariant mass region than previous measurements. The preliminary results of the analysis will be presented.

  9. Compact Hyperspectral Imaging System (cosi) for Small Remotely Piloted Aircraft Systems (rpas) - System Overview and First Performance Evaluation Results

    NASA Astrophysics Data System (ADS)

    Sima, A. A.; Baeck, P.; Nuyts, D.; Delalieux, S.; Livens, S.; Blommaert, J.; Delauré, B.; Boonen, M.

    2016-06-01

    This paper gives an overview of the new COmpact hyperSpectral Imaging (COSI) system recently developed at the Flemish Institute for Technological Research (VITO, Belgium) and suitable for remotely piloted aircraft systems. A hyperspectral dataset captured from a multirotor platform over a strawberry field is presented and explored in order to assess spectral bands co-registration quality. Thanks to application of line based interference filters deposited directly on the detector wafer the COSI camera is compact and lightweight (total mass of 500g), and captures 72 narrow (FWHM: 5nm to 10 nm) bands in the spectral range of 600-900 nm. Covering the region of red edge (680 nm to 730 nm) allows for deriving plant chlorophyll content, biomass and hydric status indicators, making the camera suitable for agriculture purposes. Additionally to the orthorectified hypercube digital terrain model can be derived enabling various analyses requiring object height, e.g. plant height in vegetation growth monitoring. Geometric data quality assessment proves that the COSI camera and the dedicated data processing chain are capable to deliver very high resolution data (centimetre level) where spectral information can be correctly derived. Obtained results are comparable or better than results reported in similar studies for an alternative system based on the Fabry-Pérot interferometer.

  10. Dwell-time dependence of the defect accumulation in focused ion beam synthesis of CoSi 2

    NASA Astrophysics Data System (ADS)

    Bischoff, Lothar; Hausmann, Stephan; Voelskow, Matthias; Teichert, Jochen

    1999-01-01

    Cobalt disilicide microstructures were formed by 70 keV Co 2+ focused ion beam implantation into Si(1 1 1) at substrate temperatures of about 400°C and a subsequent two step annealing (600°C, 60 min and 1000°C, 30 min in N 2). It was found that the CoSi 2 layer quality strongly depends on the pixel dwell time and the implantation temperature. Only for properly chosen parameters continuous CoSi 2 layers could be obtained. Scanning electron microscopy and Rutherford backscattering/channelling investigations were carried out combined with a special preparation technique for structures which are smaller than the analysing beam. The quality of the CoSi 2 layers which is correlated to the damage was investigated as a function of dwell-time (1-250 μs) and target temperature (355-415°C). The results show that the irradiation damage increases with the dwell-time. The Si top layer was amorphized for longer dwell-times although the substrate temperature was always above the critical temperature for amorphization of about 270°C according to the model of Morehead and Crowder. For the high current density of a focused ion beam (1-10 A/cm 2) the damage creation rate is higher than the rate of dynamic annealing.

  11. A latent reactive handle for functionalising heparin-like and LMWH deca- and dodecasaccharides† †Electronic supplementary information (ESI) available: Details of experimental procedures not contained in the main text and also 1H, 13C, COSY, HMQC/HSQC NMR and MS data for compounds 2–27. CCDC 998097–998099. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c5ob01706h

    PubMed Central

    Miller, Gavin J.; Broberg, Karl. R.; Rudd, Claire; Helliwell, Madeleine R.; Jayson, Gordon C.

    2015-01-01

    d-Glucosamine derivatives bearing latent O4 functionality provide modified H/HS-type disaccharide donors for a final stage capping approach enabling introduction of conjugation-suitable, non-reducing terminal functionality to biologically important glycosaminoglycan oligosaccharides. Application to the synthesis of the first O4-terminus modified synthetic LMWH decasaccharide and an HS-like dodecasaccharide is reported. PMID:26381107

  12. Search for the C-violating meson decay η → π0e+e- with WASA-at-COSY

    NASA Astrophysics Data System (ADS)

    Demmich, Kay; Bergmann, Florian; Hüsken, Nils; Khoukaz, Alfons

    2016-11-01

    TheWASA-at-COSY experiment is, besides meson production processes, dedicated to studies on rare and forbidden decays of light mesons. In extensive η-production beam times, a high-statistics data set have been collected by means of proton-proton scattering which opens the door to studies on forbidden decays like the C-parity violating process η → π0e+e-. In this article, an optimized detector calibration leading to a significantly improved missing mass resolution and a preliminary decay analysis are presented.

  13. Interactions of Cu with CoSi2, CrSi2 and TiSi2 with and without TiNx barrier layers

    NASA Astrophysics Data System (ADS)

    Olowolafe, J. O.; Li, Jian; Mayer, J. W.

    1990-12-01

    Interactions of Cu with CoSi2, CrSi2, and TiSi2 with and without interposed TiNx layers have been studied using Rutherford backscattering spectrometry, Auger electron spectrometry, x-ray diffraction, and in situ sheet resistivity measurements. Cu diffuses through a preformed CoSi2 layer to form the structure CoSi2/Cu3Si/Si(100). No dissociation of CoSi2 has been observed. For the Cu/CrSi2/Si system, the outdiffusion of Si leads to the formation of Cu3Si/CrSi2/Si at temperatures above 300 °C. At about the same temperature, Cu diffuses into a TiSi2 layer and to the TiSi2/Si interface to react with both Ti and Si forming Cu3Ti, Cu3Si, and Cu4Si phases. A 50-nm TiNx layer prepared by reactive sputtering was observed to be an effective diffusion barrier between Cu and CoSi2 or CrSi2. A 30-nm layer of TiNx simultaneously grown with TiSi2 by rapid thermal annealing proved effective between Cu and TiSi2 up to 500 °C.

  14. DFT studies of the conformational/structural dependencies of geminal 1H,1H scalar coupling 2J(H,H') in substituted methanes.

    PubMed

    Barfield, Michael

    2007-08-01

    A study is presented of the structural dependencies for scalar, interproton J-coupling across two bonds in a series of substituted methanes. The coupled perturbed, density functional theory method with a B3PW91 functional and aug-cc-pVTZ-J basis sets is used to examine coupling between geminal protons (2)J(H,H') in methane and a series of substituted compounds CH(3)X (X = CH3, CH(2)CH(3), CH=CH2, CH=O, and NH2) as functions of the dihedral angle phi measured about the C1-X2 bonds. All four contributions are obtained but all conformational effects are dominated by the Fermi contact term. Simple linear combination of atomic orbitals (LCAO)-molecular orbital (MO) sum-over-states methods are used to examine the relationships of the coupling constants with dihedral angles as well as internal H-C-H and H-C1-X2 angles. This study explores some novel aspects of geminal H-H coupling including an analysis of the asymmetry in the conformational dependencies arising from non-next-nearest neighbor interactions. For each of the substituted methanes, explicit trigonometric/exponential expressions are given and these accurately reproduce the (2)J(H,H') structural dependencies with standard deviations usually less than 0.03 Hz. The molecular structures for representative bicyclic molecules were fully optimized, and DFT results for (2)J(H,H') reproduce all the trends in the experimental data. A discussion is given on the applicability of the equations for H--H coupling in the substituted methanes to coupling in the bicyclic molecules.

  15. Antiinflammatory and Antioxidant Flavonoids and Phenols from Cardiospermum halicacabum (倒地鈴 Dào Dì Líng)

    PubMed Central

    Cheng, Hui-Ling; Zhang, Li-Jie; Liang, Yu-Han; Hsu, Ya-Wen; Lee, I-Jung; Liaw, Chia-Ching; Hwang, Syh-Yuan; Kuo, Yao-Haur

    2013-01-01

    Seventeen compounds, quercetin-3-O-α-l-rhamnoside (1), kaempferol-3-O-α-L-rhamnoside (2), apigenin-7-O-β-D-glucuronide (3), apigenin 7-O-β-D-glucuronide methyl ester (4), apigenin 7-O-β-D-glucuronide ethyl ester (5), chrysoeriol (6), apigenin (7), kaempferol (8), luteolin (9), quercetin (10), methyl 3,4-dihydroxybenzoate (11), p-coumaric acid (12), 4-hydroxybenzoic acid (13), hydroquinone (14), protocathehuic acid (15), gallic acid (16), and indole-3-carboxylic acid (17), were isolated from the ethanol extract of Taiwanese Cardiospermum halicabum. All chemical structures were determined by physical and extensive spectroscopic analyses such as 1 H Nuclear Magnetic Resonance spectroscopy (NMR), 13C NMR, 1H-1H Correlation spectroscopy (1H-1H COSY), Heteronuclear Multiple Quantum Coherence spectroscopy (HMQC), Heteronuclear Multiple-bond Correlation spectroscopy (HMBC), and Nuclear Overhauser Effect spectroscopy (NOESY), as well as comparison with literature values. Furthermore, the High-Performance Liquid Chromatography- Photodiode Array Detector (HPLC-DAD) fingerprint profile was established for the determination of major constituents in the EtOAc extract and retention times of the isolated compounds. All isolated compounds were also evaluated for antiinflammatory and antioxidant activities. PMID:24716153

  16. In situ transmission electron microscopy study on the epitaxial growth of CoSi2 on Si(111) at temperatures below 150 C

    NASA Technical Reports Server (NTRS)

    Nieh, C. W.; Lin, T. L.

    1989-01-01

    This paper reports an in situ transmission electron microscopy study on the epitaxial growth of CoSi2 on Si(111) from a 10-nm-thick amorphous mixture of Co and Si in the ratio 1:2, which was formed by codeposition of Co and Si near room temperature. Nuclei of CoSi2 are observed in the as-deposited film. These nuclei are epitaxial and extend through the whole film thickness. Upon annealing, these columnar epitaxial CoSi2 grains grow laterally at temperatures as low as 50 C. The kinetics of this lateral epitaxial growth was studied at temperatures between 50 and 150 C. The activation energy of the growth process is 0.8 + or - 0.1 eV.

  17. In situ transmission electron microscopy study on the epitaxial growth of CoSi2 on Si(111) at temperatures below 150 C

    NASA Technical Reports Server (NTRS)

    Nieh, C. W.; Lin, T. L.

    1989-01-01

    This paper reports an in situ transmission electron microscopy study on the epitaxial growth of CoSi2 on Si(111) from a 10-nm-thick amorphous mixture of Co and Si in the ratio 1:2, which was formed by codeposition of Co and Si near room temperature. Nuclei of CoSi2 are observed in the as-deposited film. These nuclei are epitaxial and extend through the whole film thickness. Upon annealing, these columnar epitaxial CoSi2 grains grow laterally at temperatures as low as 50 C. The kinetics of this lateral epitaxial growth was studied at temperatures between 50 and 150 C. The activation energy of the growth process is 0.8 + or - 0.1 eV.

  18. Versatile 1H-31P-31P COSY 2D NMR Techniques for the Characterization of Polyphosphorylated Small Molecules

    PubMed Central

    Majumdar, Ananya; Sun, Yan; Shah, Meha; Freel Meyers, Caren L.

    2010-01-01

    Di- and triphosphorylated small molecules represent key intermediates in a wide range of biological and chemical processes. The importance of polyphosphorylated species in biology and medicine underscores the need to develop methods for the detection and characterization of this compound class. We have reported two-dimensional HPP-COSY spectroscopy techniques to identify diphosphate-containing metabolic intermediates at sub-millimolar concentrations in the methylerythritol phosphate (MEP) isoprenoid biosynthetic pathway.1 In this work, we explore the scope of HPP-COSY based techniques to characterize a diverse group of small organic molecules bearing di- and tri-phosphorylated moieties. These include molecules containing P–O–P and P–C–P connectivities, multivalent P(III)–O–P(V) phosphorus nuclei with widely separated chemical shifts, as well as virtually overlapping 31P resonances exhibiting strong coupling effects. We also demonstrate the utility of these experiments to rapidly distinguish between mono- and diphosphates. A detailed protocol for optimizing these experiments to achieve best performance is presented. PMID:20408590

  19. Analysis of closed orbit deviations for a first direct deuteron electric dipole moment measurement at the cooler synchrotron COSY

    NASA Astrophysics Data System (ADS)

    Schmidt, V.; Lehrach, A.

    2017-07-01

    The Jülich Electric Dipole moment Investigations (JEDI) collaboration in Julich is preparing a direct EDM measurement of protons and deuterons first at the storage ring COSY (COoler SYnchrotron) and later at a dedicated storage ring. Ensuring a precise measurement, various beam and spin manipulating effects have to be considered and investigated. A distortion of the closed orbit is one of the major sources for systematic uncertainties. Therefore misalignments of magnets and residual power supply oscillations are simulated using the MAD-X code in order to analyse their effect on the orbit. The underlying model for all simulations includes the dipoles, quadrupoles and sextupoles at COSY as well as the corrector magnets and BPMs (Beam Position Monitors). Since most sextupoles are only used during beam extraction, the sextupole strengths are set to zero resulting in a linear machine. The optics is adjusted in a way that the dispersion is zero in the straight sections. The closed orbit studies are performed for deuterons with a momentum of 970 MeV/c.

  20. Efficiency of homonuclear Hartmann-Hahn and COSY-type mixing sequences in the presence of scalar and residual dipolar couplings.

    PubMed

    Kramer, Frank; Glaser, Steffen J

    2002-03-01

    In the presence of scalar (J) and residual dipolar (D) couplings, the transfer efficiency of homonuclear Hartmann-Hahn and COSY-type mixing depends on the ratio D/J and on the mixing sequence. This dependence is analyzed theoretically and the results are confirmed experimentally. At least two different mixing sequences are required to yield good transfer efficiencies for all ratios D/J. In contrast to COSY-type experiments, homonuclear Hartmann-Hahn sequences can provide efficient transfer even if the sum of D and J is zero, i.e., if the coupling vanishes in the weak coupling limit.

  1. The (2×2) reconstructions on the surface of cobalt silicides: Atomic configuration at the annealed Co/Si(111) interface

    NASA Astrophysics Data System (ADS)

    Kotlyar, V. G.; Alekseev, A. A.; Olyanich, D. A.; Utas, T. V.; Zotov, A. V.; Saranin, A. A.

    2017-08-01

    We have used scanning tunneling microscopy (STM) and ab initio total-energy calculations to characterize surface and interfacial structure of Co-Si(111) system. It has been found experimentally that two different types of the (2×2) surface structures occur. The coexistence of two phases is demonstrated by the example of STM image of the surface formed at the early stages of cobalt silicide formation under moderate annealing temperatures (500 °C). The measured height difference between the adjacent (2×2) reconstructed patches equal to about 1.0 Å (as determined from the filled-state STM images). In addition, the shift of the atomic rows by half of the row spacing is observed. Two adatom models of the (2×2) surface structures are developed. According to our data, these structures are assigned to CaF2-type CoSi2 and CsCl-type CoSi with a (2×2) array of Si adatoms on their surfaces. If the latter is the case, it has a coherent double interface CoSi/CoSi2/Si(111) with a two-layer CoSi2. Both of these interfaces are characterized by the eightfold cobalt coordination and incorporate a grown-in stacking fault.

  2. Application of 13C-labeling and 13C-13C COSY NMR experiments in the structure determination of a microbial natural product.

    PubMed

    Kwon, Yun; Park, Sunghyouk; Shin, Jongheon; Oh, Dong-Chan

    2014-08-01

    The elucidation of the structures of complex natural products bearing many quaternary carbons remains challenging, even in this advanced spectroscopic era. (13)C-(13)C COSY NMR spectroscopy shows direct couplings between (13)C and (13)C, which comprise the backbone of a natural product. Thus, this type of experiment is particularly useful for natural products bearing consecutive quaternary carbons. However, the low sensitivity of (13)C-based NMR experiments, due to the low natural abundance of the (13)C nucleus, is problematic when applying these techniques. Our efforts in the (13)C labeling of a microbial natural product, cyclopiazonic acid (1), by feeding (13)C-labeled glucose to the fungal culture, enabled us to acquire (13)C-(13)C COSY NMR spectra on a milligram scale that clearly show the carbon backbone of the compound. This is the first application of (13)C-(13)C COSY NMR experiments for a natural product. The results suggest that (13)C-(13)C COSY NMR spectroscopy can be routinely used for the structure determination of microbial natural products by (13)C-enrichment of a compound with (13)C-glucose.

  3. Fabrication and electrical transport properties of binary Co-Si nanostructures prepared by focused electron beam-induced deposition

    SciTech Connect

    Porrati, F.; Huth, M.; Kaempken, B.; Terfort, A.

    2013-02-07

    CoSi-C binary alloys have been fabricated by focused electron beam-induced deposition by the simultaneous use of dicobaltoctacarbonyl, Co{sub 2}(CO){sub 8}, and neopentasilane, Si{sub 5}H{sub 12}, as precursor gases. By varying the relative flux of the precursors, alloys with variable chemical composition are obtained, as shown by energy dispersive x-ray analysis. Room temperature electrical resistivity measurements strongly indicate the formation of cobalt silicide and cobalt disilicide nanoclusters embedded in a carbonaceous matrix. Temperature-dependent electrical conductivity measurements show that the transport properties are governed by electron tunneling between neighboring CoSi or CoSi{sub 2} nanoclusters. In particular, by varying the metal content of the alloy, the electrical conductivity can be finely tuned from the insulating regime into the quasi-metallic tunneling coupling regime.

  4. CoSi2 growth on Si(001) by reactive deposition epitaxy: Effects of high-flux, low-energy ion irradiation

    NASA Astrophysics Data System (ADS)

    Lim, C. W.; Greene, J. E.; Petrov, I.

    2006-07-01

    CoSi2 layers, <40nm thick, were grown on Si(001) by reactive deposition epitaxy (RDE) in which Co was deposited at 700°C by magnetically unbalanced ultrahigh vacuum magnetron sputtering. X-ray diffraction pole figures and transmission electron microscopy (TEM) reveal that the layers, which exhibit a cube-on-cube epitaxial relationship with the substrate, (001)CoSi2‖(001)Si and [100]CoSi2‖[100]Si, contain fourfold symmetric {111} twinned domains oriented such that {221}CoSi2‖(001)Si and ⟨110⟩CoSi2‖[110]Si. We demonstrate that high-flux low-energy (EAr+=9.6eV) Ar+ ion irradiation during deposition dramatically increases the area fraction fu of untwinned regions from 0.17 in films grown under standard magnetically balanced conditions in which the ratio JAr+/JCo of the incident Ar+ to Co fluxes is 1.4 to 0.72 with JAr+/JCo=13.3. TEM analyses show that the early stages of RDE CoSi2(001) film growth proceed via the Volmer-Weber mode with independent nucleation of both untwinned and twinned islands. Increasing JAr+/JCo results in larger values of both the number density and area of untwinned with respect to twinned islands. The intense Ar+ ion bombardment creates additional low-energy adsorption sites that favor the nucleation of untwinned islands while collisionally enhancing Co surface mobilities which, in turn, increases the probability of itinerant Co adatoms reaching these sites.

  5. Evaluation of two-dimensional L-COSY and JPRESS using a 3 T MRI scanner: from phantoms to human brain in vivo.

    PubMed

    Thomas, M Albert; Hattori, Noriaki; Umeda, Masahiro; Sawada, Tohru; Naruse, Shoji

    2003-08-01

    Localized versions of two-dimensional (2D) magnetic resonance spectroscopic (MRS) sequences, namely JPRESS and L-COSY, have been implemented on a whole-body 3T MRI/MRS scanner. Volume selection was achieved using three slice-selective radio-frequency (RF) pulses: 90 degrees-180 degrees-180 degrees in JPRESS and 90 degrees-180 degrees-90 degrees in L-COSY with a CHESS sequence prior to voxel localization for global water suppression. The last 180 degrees RF pulse was used for resolving the J-coupled cross peaks in JPRESS, whereas the last 90 degrees RF pulse was used for coherence transfer between J-coupled metabolites in L-COSY. A head MRI coil for 'transmission' and a 4 inch receive surface coil for 'reception' or a head coil transmit/receive were used. A total of 16 healthy volunteers were investigated using these 2D MRS sequences. Voxel sizes of 18 and 27 ml were localized in the occipito-parietal gray and white matter regions and the total duration for each 2D signal acquisition was typically 35 min. Compared with 2D L-COSY, reduced spectral width along the second spectral dimension and shorter 2D spectral acquisition were the major advantages of 2D JPRESS. In contrast, increased spectral width along the new spectral dimension in L-COSY resulted in an improved spectral dispersion enabling the detection of several brain metabolites at low concentrations that have not been resolved using the conventional one-dimensional (1D) MRS techniques. Due to increased sampling rate, severe loss of metabolite signals due to T2 during t1 was a major drawback of 2D JPRESS in vivo. Copyright 2003 John Wiley & Sons, Ltd.

  6. Interactions of transition metals with silicon(100): The Ni-Si, Co-Si and Au/Si(100) systems

    NASA Astrophysics Data System (ADS)

    Naftel, Steven James

    1999-11-01

    This thesis encompasses studies of the electronic and physical structure of three transition metal interfaces with Si(100) substrates. The first case concerns a high resolution photoemission (PES) study of the initial stages (0 to ˜ 25 ML) of the formation of the Au/Si(100) interface at room temperature. The interface was studied using Si 2p and Au 4f core-level PES, using synchrotron radiation. It was found that the Au and Si react immediately upon deposition to form a Au-Si phase. This initial Au-Si phase is seen to change to a second Au-Si phase by 3.6 ML (1 ML = 6.78 x 1014 atoms/cm 2) of Au coverage. As the coverage is increased a layer of the second Au-Si phase remains on the surface while pure Au layers form underneath it. Second we report a Si L3,2 -, Si K-, Co L3,2 - and Co K-edge X-ray absorption near-edge structures (XANES) study of a series of cobalt and cobalt silicide thin films prepared by thermally annealing deposited Co layers on Si(100) substrates. By collecting both Total Electron Yield (TEY) and Fluorescence Yield (FLY) XANES at the above edges we monitored the electronic and physical structural differences between films annealed under different conditions. It was found that the as deposited Co film exhibits noticeable intermixing at the Co-Si interface. The annealed films consisted of CoSi2; however, both SiO2 and metallic Co were found in the near surface region of these films. The origin of the metallic Co remains undetermined. Thirdly, we report a Si L3,2 -, Si K-, Ni L3,2 - and Ni K-edge, TEY and FLY XANES study of a series of nickel and nickel silicide thin films prepared by thermally annealing deposited Ni layers on Si(100) substrates. The unannealed films again showed noticeable intermixing at the Ni-Si interface. The annealed Ni films produced primarily NiSi and NiSi2 films depending on the final annealing temperature. Using the XANES spectra from the Ni-Si blanket films as a reference we determined that Ni-Si sub-micron lines formed

  7. Resveratrol tetramer of hopeaphenol isolated from Shorea johorensis (Dipterocarpaceae)

    NASA Astrophysics Data System (ADS)

    Aisha, Farra; Din, Laily B.; Yaacob, W. A.

    2014-09-01

    Hopeaphenol (1) as a resveratrol tetramer was isolated from the bark of Shorea johorensis collected from Imbak Canyon, Sabah, Malaysia. The structure of this compound was determined by the spectroscopic evidences using 1H- and 13C-NMR assigned with HSQC, HMBC, 1H-1H COSY and 1H-1H NOESY spectra, mass spectrum, and by comparison with reported data.

  8. Increased effective barrier heights in Schottky diodes by molecular-beam epitaxy of CoSi2 and Ga-doped Si on Si(111)

    NASA Technical Reports Server (NTRS)

    Fathauer, R. W.; Lin, T. L.; Grunthaner, P. J.; Andersson, P. O.; Iannelli, J. M.

    1988-01-01

    Increasing the effective Schottky-barrier height of epitaxial CoSi2/Si(111) diodes by the use of thin, highly doped Si layers in close proximity to the metal-semiconductor interface has been studied. Intrinsic Si, Si doped by coevaporation of Ga, and epitaxial CoSi2 layers have all been grown in the same molecular-beam epitaxy system. Current-voltage and photoresponse characterization yield barrier heights ranging from 0.61 eV for a sample with no p(+) layer to 0.89 eV for a sample with a 20-nm-thick p(+) layer. These results are compared to theoretical values based on a one-dimensional solution of Poisson's equation under the depletion approximation.

  9. BIG KARL and COSY: Examples for high performance magnet design taught by {open_quotes}Papa Klaus{close_quotes}

    SciTech Connect

    Bechtstedt, U.; Hacker, U.; Maier, R.; Martin, S.; Berg, G.P.A.; Hardt, A.; Huerlimann, W.; Meissburger, J.; Roemer, J.G.M.

    1995-02-01

    The past decades have seen a tremendous development in nuclear, middle, and high energy physics. This advance was in a great part promoted by the availability of newer and more powerful instruments. Over time, these instruments grew in size as well as in sophistication and precision. Nearly all these devices had one fundamental thing in common - magnetic fields produced with currents and iron. The precision demanded by the new experiments and machines did bring the magnet technology to new frontiers requiring the utmost in the accuracy of magnetic fields. The complex properties of the iron challenged innumerable physicists in the attempt to force the magnetic fields into the desired shape. Experience and analytical insight were the pillars for coping with those problems and only few mastered the skills and were in addition able to communicate their intricate knowledge. It was a fortuitous situation that the authors got to know Klaus Halbach who belonged to those few and who shared his knowledge contributing thus largely to the successful completion of two large instruments that were built at the Forschungszentrum Juelich, KFA, for nuclear and middle energy physics. In one case the efforts went to the large spectrometer named BIG KARL whose design phase started in the early 70`s. In the second case the work started in the early 80`s with the task to build a high precision 2.5 GeV proton accelerator for cooled stored and extracted beams known as COSY-Juelich.

  10. Formation of Bamboo-Like Carbon Nanotubes and Nanofibers Using Co-Si-O and Co-Si Catalysts

    NASA Astrophysics Data System (ADS)

    Chang, Hui Lin; Tzu Kuo, Cheng

    2010-04-01

    Bamboo-like carbon nanotubes were synthesized by microwave plasma chemical vapor deposition (MPCVD) using CH4 and N2 as source gases in various ratios. Two types of catalytic films, namely, a condition 1, Co film/SiO2/Si substrate, and, a Co film/Si substrate layer with rapid thermal annealing (RTA; condition 2), were used as catalysts to grow carbon nanotubes. The interaction between the catalytic film and the Si substrate or between the catalytic film and the SiO2 interlayer occurred during the H2 reduction step before nanotube growth. The chemical compositions of catalytic particles capping the carbon nanotubes were identified by energy-dispersive X-ray spectroscopy (EDS) as Co-Si-O and Co-Si for conditions 1 and 2, respectively. The growth of the base and tip growths was investigated and is suggested to be governed by the capillary effect and the strength of adhesion between the catalytic particles and the underlayer. Transmission electron microscopy (TEM) analysis reveals that the carbon nanotubes and nanofibers have bamboo-like structures with hollow internal compartments. The formation mechanisms of these bamboo-like structures are discussed.

  11. Isovalent substitutes play in different ways: Effects of isovalent substitution on the thermoelectric properties of CoSi0.98B0.02

    NASA Astrophysics Data System (ADS)

    Sun, Hui; Lu, Xu; Morelli, Donald T.

    2016-07-01

    Boron-added CoSi, CoSi0.98B0.02, possesses a very high thermoelectric power factor of 60 μW cm-1 K-2 at room temperature, which is among the highest power factors that have ever been reported for near-room-temperature thermoelectric applications. Since the electrical properties of this material have been tuned properly, isovalent substitution for its host atoms is intentionally employed to reduce the lattice thermal conductivity while maintaining the electronic properties unchanged. In our previous work, the effect of Rh substitution for Co atoms on the thermoelectric properties of CoSi0.98B0.02 has been studied. Here, we present a study of the substitution of Ge for Si atoms in this compound. Even though Ge and Rh are isovalent with their corresponding host atoms, they play different roles in determining the electrical and thermal transport properties. Through the evaluation of the lattice thermal conductivity by the Debye approximation and the comparison between the high-temperature Seebeck coefficients, we propose that Rh substitution leads to a further overlapping of the conduction and the valence bands, while Ge substitution only shifts the Fermi level upward into the conduction band. Our results show that the influence of isovalent substitution on the electronic structure cannot be ignored when the alloying method is used to improve thermoelectric properties.

  12. Isovalent substitutes play in different ways: Effects of isovalent substitution on the thermoelectric properties of CoSi0.98B0.02

    DOE PAGES

    Sun, Hui; Lu, Xu; Morelli, Donald T.

    2016-07-21

    Boron-added CoSi, CoSi0.98B0.02, possesses a very high thermoelectric power factor of 60 μW cm-1 K-2 at room temperature, which is among the highest power factors that have ever been reported for near-room-temperature thermoelectric applications. Since the electrical properties of this material have been tuned properly, isovalent substitution for its host atoms are intentionally employed to reduce the lattice thermal conductivity while maintaining the electronic properties unchanged. In our previous work, the effect of Rh substitution for Co atoms on the thermoelectric properties of CoSi0.98B0.02 has been studied. Here we present a study of the substitution of Ge for Si atomsmore » in this compound. Even though Ge and Rh are isovalent with their corresponding host atoms, they play different roles in determining the electrical and thermal transport properties. Through the evaluation of the lattice thermal conductivity by the Debye approximation and the comparison between the high-temperature Seebeck coefficients, we propose that Rh substitution leads to a further overlapping of the conduction and the valence bands while Ge substitution only shifts the Fermi level upward into the conduction band. Lastly, our results show that the influence of isovalent substitution on the electronic structure cannot be ignored when the alloying method is used to improve thermoelectric properties.« less

  13. Growth of single-crystal columns of CoSi2 embedded in epitaxial Si on Si(111) by molecular beam epitaxy

    NASA Technical Reports Server (NTRS)

    Fathauer, R. W.; Nieh, C. W.; Xiao, Q. F.; Hashimoto, Shin

    1989-01-01

    The codeposition of Si and Co on a heated Si(111) substrate is found to result in epitaxial columns of CoSi2 if the Si:Co ratio is greater than approximately 3:1. These columns are surrounded by an Si matrix which shows bulk-like crystalline quality based on transmission electron microscopy and ion channeling. This phenomenon has been studied as functions of substrate temperature and Si:Co ratio. Samples with columns ranging in average diameter from approximately 25 to 130 nm have been produced.

  14. Growth of single-crystal columns of CoSi2 embedded in epitaxial Si on Si(111) by molecular beam epitaxy

    NASA Technical Reports Server (NTRS)

    Fathauer, R. W.; Nieh, C. W.; Xiao, Q. F.; Hashimoto, Shin

    1989-01-01

    The codeposition of Si and Co on a heated Si(111) substrate is found to result in epitaxial columns of CoSi2 if the Si:Co ratio is greater than approximately 3:1. These columns are surrounded by an Si matrix which shows bulk-like crystalline quality based on transmission electron microscopy and ion channeling. This phenomenon has been studied as functions of substrate temperature and Si:Co ratio. Samples with columns ranging in average diameter from approximately 25 to 130 nm have been produced.

  15. Family socioeconomic status and nutrition habits of 7-8 year old children: cross-sectional Lithuanian COSI study.

    PubMed

    Petrauskienė, Aušra; Žaltauskė, Vilma; Albavičiūtė, Edita

    2015-04-23

    Nutritional habits are a useful way to characterize whole diets and they are also known to be influenced by a wide range of social and economic factors. The above factors in each country may have different effect on children's eating habits. In Lithuania the data of children nutrition in association with socio-economic status of family is poor. There are few studies done, where links between nutrition habits of children and socio-economic status of family was evaluated. The aim of this paper is to evaluate association among nutrition habits of first-formers and family socio-economic status in Lithuania. Data were obtained participating in the international study, which was performed in all ten districts of Lithuania. A cross-sectional study was carried out in 2010, using the protocol and methodology prepared by the experts from the WHO and countries participating in the Initiative. The data were collected by means of COSI standardized questionnaire, which was filled out by parents of selected first-formers'. In this paper a part of questions regarding children nutrition habits and parents' socio-economic status is presented. Statistical analysis was performed by using SPSS 20.0 software for Windows. Correlation among variables was evaluated by χ (2). Links among nutrition habits of first-formers and family socioeconomic status were determined using binary logistic regression to calculate odds ratios (OR) and 95% confidence intervals (CI). For all tests p < 0.05 was considered significant. It was established that the majority (76%) of Lithuanian first-formers eat breakfast every day or 4-6 times a week. Significant differences were found between breakfast consumption and gender - girls eat breakfast less frequently than boys. Odds ratio of children daily breakfast consumption were 1.3 times higher in families where fathers' were older than 30 years comparing with younger fathers. Meanwhile mothers' age had significant influence just on children daily soft drinks

  16. Resistance Switching Memory Characteristics of Si/CaF2/CdF2 Quantum-Well Structures Grown on Metal (CoSi2) Layer

    NASA Astrophysics Data System (ADS)

    Denda, Junya; Uryu, Kazuya; Watanabe, Masahiro

    2013-04-01

    A novel scheme of resistance switching random access memory (ReRAM) devices fabricated using Si/CaF2/CdF2/CaF2/Si quantum-well structures grown on metal CoSi2 layer formed on a Si substrate has been proposed, and embryonic write/erase memory operation has been demonstrated at room temperature. It has been found that the oxide-mediated epitaxy (OME) technique for forming the CoSi2 layer on Si dramatically improves the stability and reproducibility of the current-voltage (I-V) curve. This technology involves 10-nm-thick Co layer deposition on a protective oxide prepared by boiling in a peroxide-based solution followed by annealing at 550 °C for 30 min for silicidation in ultrahigh vacuum. A switching voltage of lower than 1 V, a peak current density of 32 kA/cm2, and an ON/OFF ratio of 10 have been observed for the sample with the thickness sequence of 0.9/0.9/2.5/0.9/5.0 nm for the respective layers in the Si/CaF2/CdF2/CaF2/Si structure. Results of surface morphology analysis suggest that the grain size of crystal islands with flat surfaces strongly affects the quality of device characteristics.

  17. Self-aligned silicides for Ohmic contacts in complementary metal-oxide-semiconductor technology: TiSi2, CoSi2, and NiSi

    NASA Astrophysics Data System (ADS)

    Zhang, S.-L.; Smith, U.

    2004-07-01

    Metal silicides continue to play an indispensable role during the remarkable development of microelectronics. Along with several other technological innovations, the implementation of the self-aligned silicide technology paved the way for a rapid and successful miniaturization of device dimensions for metal-oxide-semiconductor field-effect transistors (MOSFETs) in pace with the Moore's law. The use of silicides has also evolved from creating reliable contacts for diodes, to generating high-conductivity current paths for local wiring, and lately to forming low-resistivity electrical contacts for MOSFETs. With respect to the choice of silicides for complementary metal-oxide-semiconductor (CMOS) technology, a convergence has become clear with the self-alignment technology using only a limited number of silicides, namely TiSi2, CoSi2, and NiSi. The present work discusses the advantages and limitations of TiSi2, CoSi2, and NiSi using the development trend of CMOS technology as a measure. Specifically, the reactive diffusion and phase formation of these silicides in the three terminals of a MOSFET, i.e., gate, source, and drain, are analyzed. This work ends with a brief discussion about future trends of metal silicides in micro/nanoelectronics with reference to potential material aspects and device structures outlined in the International Technology Roadmap for Semiconductors. .

  18. Sesquiterpenes inhibiting the microglial activation from Laurus nobilis.

    PubMed

    Chen, Hongqiang; Xie, Chunfeng; Wang, Hao; Jin, Da-Qing; Li, Shen; Wang, Meicheng; Ren, Quanhui; Xu, Jing; Ohizumi, Yasushi; Guo, Yuanqiang

    2014-05-21

    The inhibitory reagents to inhibit the activation of microglial cells may be potentially useful for the treatment of neurodegenerative diseases. The leaves of the plant Laurus nobilis belonging to the family Lauraceae, namely, bay leaves, have been used as a popular spice, and their extract showed moderate inhibition on microglial activation. A further phytochemical investigation of the leaves led to the isolation of two new (1, 2) and eight known (3-10) sesquiterpenes. Their structures were elucidated on the basis of extensive 1D and 2D NMR (HMQC, HMBC, (1)H-(1)H COSY, and NOESY) spectroscopic data analyses and Chem3D modeling. The following biological studies disclosed that these isolated compounds showed inhibitory activities on LPS-induced microglial activation. The results of our phytochemical investigation, including two new sesquiterpenes (1 and 2) and the first report of two compounds (3 and 4) from this species, further revealed the chemical composition of bay leaves as a popular spice, and the biological studies implied that bay leaves, containing bioactive substances with the inhibition of microglial activation, were potentially beneficial to human health.

  19. Isolation and structure determination of one new metabolite isolated from the red fermented rice of Monascus purpureus.

    PubMed

    Cheng, Ming-Jen; Chen, Jih-Jung; Wu, Ming-Der; Yang, Ping-Shin; Yuan, Gwo-Fang

    2010-06-01

    The n-BuOH-soluble portion of the 95% EtOH extract of red fermented rice fermented with the yellow mutant of the fungus Monascus purpureus BCRC 38113 (Monascaceae) led to the isolation of one new pyran-2-one derivative, namely peroxymonascuspyrone (1), along with nine known compounds, monasfluore A (2), monasfluore B (3), 3-epi-betulinic acid (4), 3-epi-betulinic acid acetate (5), alpha-tocospiro A (6), friedelan-3-one (7), alpha-cadinol (8), anticopalol (9), and spathulenol (10). Interestingly, this is the first report of a naturally occurring pyran-2-one skeleton isolated from Monascus sp. Their structures and relative configurations were elucidated by spectroscopic methods, including 1D- and 2D-NMR ((1)H,(1)H-COSY, HMQC, HMBC and NOESY), as well as low- and high-resolution mass spectrometric analyses. In addition, cytotoxicities against MCF-7, NCI-H460 and SF-268 cancer cell lines were measured in vitro; the results revealed that these metabolites have no cytotoxicity against the selected tumour cells.

  20. Amaryllidaceae alkaloids from the bulbs of Lycoris radiata with cytotoxic and anti-inflammatory activities.

    PubMed

    Liu, Zhi-Ming; Huang, Xiao-Yun; Cui, Mao-Rong; Zhang, Xiao-De; Chen, Zhao; Yang, Ben-Shou; Zhao, Xiao-Kun

    2015-03-01

    Four new Amaryllidaceae alkaloids, (+)-1-hydroxy-ungeremine (1), (+)-6β-acetyl-8-hydroxy-9-methoxy-crinamine (2), (+)-2-hydroxy-8-demethyl-homolycorine-α-N-oxide (3), (+)-N-methoxylcarbonyl-2-demethyl-isocorydione (4), together with two known compounds, (+)-6β-acetyl-crinamine (5) and 8-demethyl-homolycorine-α-N-oxide (6) were isolated from the ethanol extract of the bulbs of Lycoris radiata. Structural elucidation of all the compounds were performed by spectral methods such as 1D and 2D ((1)H-(1)H COSY, HMQC, and HMBC) NMR spectroscopy, in addition to high resolution mass spectrometry. All the isolated alkaloids were in vitro evaluated for their cytotoxic activities against eight tumor cell lines (BEN-MEN-1, CCF-STTG1, CHG-5, SHG-44, U251, BGC-823, HepG2 and SK-OV-3) and anti-inflammatory activities against Cox-1 and Cox-2. As a result, alkaloids 1 and 4 exhibited significant cytotoxic activities against all tested tumor cell lines except against BEN-MEN-1. Additionally, alkaloids 1 and 4 possessed selective inhibition of Cox-2 comparable with the standard drug NS-398 (>90%).

  1. Cytotoxic and antimalarial amaryllidaceae alkaloids from the bulbs of Lycoris radiata.

    PubMed

    Hao, Bin; Shen, Shu-Fang; Zhao, Qing-Jie

    2013-02-25

    Phytochemical investigation of the 80% ethanol extract of the bulbs of Lycoris radiata resulted in the isolation of five new Amaryllidaceae alkaloids: (+)-5,6-dehydrolycorine (1), (+)-3α,6β-diacetyl-bulbispermine (2), (+)-3α-hydroxy-6β-acetyl- bulbispermine (3), (+)-8,9-methylenedioxylhomolycorine-N-oxide (5), and 5,6-dihydro-5- methyl-2-hydroxyphenanthridine (7), together with two known compounds, (+)-3α-methoxy- 6β-acetylbulbispermine (4) and (+)-homolycorine- N-oxide (6). Structural elucidation of all the compounds were performed by spectral methods such as 1D and 2D (1H-1H COSY, HMQC, and HMBC) NMR spectroscopy, in addition to high resolution mass spectrometry. Alkaloid 1 showed potent cytotoxicity against astrocytoma and glioma cell lines (CCF-STTG1, CHG-5, SHG-44, and U251), as well as HL-60, SMMC-7721, and W480 cell lines with IC(50) values of 9.4-11.6 μM. Additonally, compound 1 exhibited antimalarial activity with IC(50) values of 2.3 μM for D-6 strain and 1.9 μM for W-2 strain of Plasmodium falciparum.

  2. Chaetopyranin, a benzaldehyde derivative, and other related metabolites from Chaetomium globosum, an endophytic fungus derived from the marine red alga Polysiphonia urceolata.

    PubMed

    Wang, Song; Li, Xiao-Ming; Teuscher, Franka; Li, Dong-Li; Diesel, Arnulf; Ebel, Rainer; Proksch, Peter; Wang, Bin-Gui

    2006-11-01

    Cultivation of the endophytic fungus Chaetomium globosum, which was isolated from the inner tissue of the marine red alga Polysiphonia urceolata, resulted in the isolation of chaetopyranin (1), a new benzaldehyde secondary metabolite. Ten known compounds were also isolated, including two benzaldehyde congeners, 2-(2',3-epoxy-1',3'-heptadienyl)-6-hydroxy-5-(3-methyl-2-butenyl)benzaldehyde (2) and isotetrahydroauroglaucin (3), two anthraquinone derivatives, erythroglaucin (4) and parietin (5), five asperentin derivatives including asperentin (6, also known as cladosporin), 5'-hydroxy-asperentin-8-methylether (7), asperentin-8-methyl ether (8), 4'-hydroxyasperentin (9), and 5'-hydroxyasperentin (10), and the prenylated diketopiperazine congener neoechinulin A (11). The structures of these compounds were determined on the basis of their spectroscopic data analysis (1H, 13C, 1H-1H COSY, HMQC, and HMBC NMR, as well as low- and high-resolution mass experiments). To our knowledge, compound 1 represents the first example of a 2H-benzopyran derivative of marine algal-derived fungi as well as of the fungal genus Chaetomium. Each isolate was tested for its DPPH (1,1-diphenyl-2-picrylhydrazyl) radical-scavenging property. Compounds 1-4 were found to have moderate activity. Chaetopyranin (1) also exhibited moderate to weak cytotoxic activity toward several tumor cell lines.

  3. Structure of the O-polysaccharide leads to classification of Proteus penneri 31 in Proteus serogroup O19.

    PubMed

    Kondakova, Anna N; Zych, Krystyna; Senchenkova, Sof'ya N; Zabłotni, Agnieszka; Shashkov, Alexander S; Knirel, Yuriy A; Sidorczyk, Zygmunt

    2003-10-24

    O-polysaccharide was obtained by mild acid degradation of the lipopolysaccharide (LPS) of Proteus penneri strain 31. Sugar and methylation analyses along with NMR spectroscopic studies, including 2D 1H,1H COSY, TOCSY, ROESY, 1H,13C and 1H,31P HMQC experiments, demonstrated the following structure of the polysaccharide: [carbohydrate structure: see text] where FucNAc is 2-acetamido-2,6-dideoxygalactose and EtnP is 2-aminoethyl phosphate. The polysaccharide studied has the same carbohydrate backbone as the O-polysaccharide of Proteus vulgaris O19. Based on this finding and close serological relatedness of the LPS of the two strains, it is proposed to classify P. penneri 31 in Proteus serogroup O19 as an additional subgroup. In contrast, D-GlcNAc6PEtn and alpha-L-FucNAc-(1-->3)-D-GlcNAc shared with a number of other Proteus O-polysaccharides could not provide any significant cross-reactivity of the corresponding LPS with rabbit polyclonal O-antiserum against P. penneri 31.

  4. 1H, 13C NMR spectral and single crystal structural studies of toxaphene congeners. Quantum chemical calculations for preferred conformers of 2,5- endo,6- exo,8,9,9,10,10-octachloro-2-bornene and their DFT/GIAO 13C chemical shifts

    NASA Astrophysics Data System (ADS)

    Laihia, K.; Valkonen, A.; Kolehmainen, E.; Suontamo, R.; Nissinen, M.; Nikiforov, V.; Selivanov, S.

    2005-11-01

    The 1H and 13C NMR chemical shifts for six toxaphene congeners: 2- exo,3- endo,6- exo,8,9,10-hexachloro- ( 1), 2- exo,3- endo,5- exo,9,9,10,10-heptachloro- ( 2), 2- exo,3- endo,6- exo,8,9,10,10-heptachloro- ( 3), 2- exo,3- endo,5- exo,6- endo,8,9,10-heptachloro- ( 4), 2- exo,3- endo,5- exo,6- endo,8,9,9,10-octachlorobornane ( 5) and 2,5- endo,6- exo,8,9,9,10,10-octachloro-2-bornene ( 6) are reported. Their chemical shift assignments have been obtained by means of Pulsed Field Gradient (PFG) Double Quantum Filtered (DQF) 1H, 1H correlation spectroscopy (COSY), PFG 1H, 13C Heteronuclear Multiple Quantum Coherence (HMQC) and PFG 1H, 13C Heteronuclear Multiple Bond Correlation (HMBC) experiments. A single crystal X-ray structural analysis was made for compounds 1, 3, 4 and 6. The prevalences of two octachlorobornene rotamers ( 6 a, 6 b) were elucidated by ab initio MO method and single point DFT/GIAO calculations for 13C chemical shifts. Theoretical calculations proved that the single crystal structure of 6 corresponds its most stable conformer in solution.

  5. Neuroprotective and antioxidant lanostanoid triterpenes from the fruiting bodies of Ganoderma atrum.

    PubMed

    Qiu, Junming; Wang, Xiang; Song, Chengguang

    2016-03-01

    Five new lanostanoid triterpenes were isolated from the ethanol extract of the fruiting bodies of Ganoderma atrum. The structures of the isolated compounds were established based on 1D and 2D ((1)H-(1)H COSY, HMQC, and HMBC) NMR spectroscopy, in addition to high resolution mass spectrometry. The isolated compounds were tested in vitro for neuroprotective activities against 6-OHDA-induced cell death in SH-SY5Y cells and radical scavenging activities. As a result, compounds 2 and 5 exhibited potent neuroprotective activity against 6-OHDA-induced cell death in SH-SY5Y cells with the lowest IC50 value (0.5 μM) while compounds 1, 3 and 4 possessed significant neuroprotective activity with IC50 value less than 10 μM. Additionally, all tested compounds 1-6 showed the comparable free radical scavenging activities with the standard drug trolox in both ABTS (+) and DPPH experiment. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. New chromone and triglyceride from Cucumis melo seeds.

    PubMed

    Ibrahim, Sabrin R M

    2014-02-01

    Re-investigation of the MeOH extract of the seeds of Cucumis melo L. var. reticulatus (Cucurbitaceae) led to the isolation of a new chromone derivative (5,7- dihydroxy-2-[2-(3-methoxy-4-hydroxyphenyl)ethyl]chromone (5) and a triglyceride (1,3-di-(6Z,9Z)-docosa-6,9-dienoyl-2-(6Z) hexacos-6-enoylglycerol (1), together with three known compounds; alpha-spinasterol (2), stigmasta-7,22,25-trien-3-ol (3), and D:B-friedoolean-5-ene-3-beta-ol (4), are reported from this species for the first time. Their structures were determined by extensive 1D (1H, 13C, and DEPT) and 2D (1H-1H COSY, HMQC, and HMBC) NMR and mass spectral measurements. Compound 5 displayed significant cytotoxic activity against L5178Y cells, with an ED50 of 5 microM. The MeOH extract and 5 showed antioxidant activity using the DPPH assay.

  7. NMR assignments of the major cannabinoids and cannabiflavonoids isolated from flowers of Cannabis sativa.

    PubMed

    Choi, Young Hae; Hazekamp, Arno; Peltenburg-Looman, Anja M G; Frédérich, Michel; Erkelens, Cornelis; Lefeber, Alfons W M; Verpoorte, Robert

    2004-01-01

    The complete 1H- and 13C-NMR assignments of the major Cannabis constituents, delta9-tetrahydrocannabinol, tetrahydrocannabinolic acid, delta8-tetrahydrocannabinol, cannabigerol, cannabinol, cannabidiol, cannabidiolic acid, cannflavin A and cannflavin B have been determined on the basis of one- and two-dimensional NMR spectra including 1H- and 13C-NMR, 1H-1H-COSY, HMQC and HMBC. The substitution of carboxylic acid on the cannabinoid nucleus (as in tetrahydrocannabinolic acid and cannabidiolic acid) has a large effect on the chemical shift of H-1" of the C5 side chain and 2'-OH. It was also observed that carboxylic acid substitution reduces intermolecular hydrogen bonding resulting in a sharpening of the H-5' signal in cannabinolic acid in deuterated chloroform. The additional aromaticity of cannabinol causes the two angular methyl groups (H-8 and H-9) to show identical 1H-NMR shifts, which indicates that the two aromatic rings are in one plane in contrast to the other cannabinoids. For the cannabiflavonoids, the unambiguous assignments of C-3' and C-4' of cannflavin A and B were determined by HMBC spectra.

  8. Determination of ¹J(⁵⁹Co-⁵⁹Co) scalar coupling constants in the tetrahedral mixed-metal cluster HFeCo₃(CO)₁₀(PCyH₂)(PPh₂[CH₂C(O)Ph]) using COSY-type NMR experiments.

    PubMed

    Kempgens, Pierre; Rosé, Jacky

    2011-03-01

    Two-dimensional ⁵⁹Co correlation spectroscopy (COSY) and double-quantum-filtered (DQF) COSY NMR experiments are reported for the tetrahedral mixed-metal cluster HFeCo₃(CO)₁₀(PCyH₂)(PPh₂[CH₂C(O)Ph]), which consists from the point of view of ⁵⁹Co NMR spectroscopy, of an AMX system of three-spin S=7/2. Both 2D NMR spectra prove the existence of a J scalar coupling constant between non-equivalent ⁵⁹Co nuclei. By contrast to what happens with the conventional 2D ⁵⁹Co COSY NMR spectrum, it was possible to simulate the 2D ⁵⁹Co DQF-COSY NMR spectrum by density matrix calculations in order to extract the values of the ¹J(⁵⁹Co-⁵⁹Co) coupling constants. The comparison between experimental and theoretical 2D NMR spectra gives spin-couplings constants of several hundreds Hertz for this cluster. Copyright © 2010 Elsevier Inc. All rights reserved.

  9. Using LabVIEW for the design and control of digital signal processing systems Simulation of the ultra slow extraction at COSY

    NASA Astrophysics Data System (ADS)

    Heinrichs, G.; Rongen, H.; Jamal, R.

    1994-12-01

    For the ultraslow extraction system of the COler SYnchrotron COSY a direct digital synthesis system is being developed. LabVIEW from National Instruments has been chosen as a tool for the simulation of the digital signal processing algorithms as well as the generation of test sequences. In order to generate adjustable band-limited noise centered at a carrier frequency, alternative algorithms have been studied. LabVIEW permits the interactive variation of relevant system parameters by means of a graphical language in order to study the quality of the frequency band limitation as a function of noise parameters, digital accuracy and frequency range and to generate test sequences by means of a real-time function generator. Advantages and limitations of LabVIEW for such applications are discussed.

  10. The usefulness of 2D DOSY and 3D DOSY-COSY 1H NMR for mixture analysis: application to genuine and fake formulations of sildenafil (Viagra).

    PubMed

    Trefi, Saleh; Gilard, Véronique; Balayssac, Stéphane; Malet-Martino, Myriam; Martino, Robert

    2009-12-01

    Two-dimensional diffusion ordered spectroscopy (DOSY) (1)H NMR is proposed to analyze drugs that are complex mixtures in order to discriminate genuine from fake formulations. The method was applied to the analysis of 17 formulations of sildenafil, one being genuine Viagra and the others illegally manufactured formulations of this drug coming from India, Syria and China. It enabled (i) distinguishing imitations or counterfeit from the authentic formulation, (ii) detecting the presence of sildenafil or adulterants, (iii) gaining information on the formulation process by detection of various excipients, thus giving a precise and global 'signature' of the manufacturer. Even though some samples are slightly overdosed, the quality of products manufactured in India and Syria was better than that of Chinese formulations which were adulterated with vardenafil and homosildenafil. This study also presents a three-dimensional DOSY-COSY (1)H NMR experiment that provides both virtual separation and structural information.

  11. Image cross-correlation using COSI-Corr: A versatile technique to monitor and quantity surface deformation in space and time

    NASA Astrophysics Data System (ADS)

    Leprince, S.; Ayoub, F.; Avouac, J.

    2011-12-01

    We have developed a suite of algorithms for precise Co-registration of Optically Sensed Images and Correlation (COSI-Corr) which were implemented in a software package first released to the academic community in 2007. Its capability for accurate surface deformation measurement has proved useful for a wide variety of applications. We present the fundamental principles of COSI-Corr, which are the key ingredients to achieve sub-pixel registration and sub-pixel measurement accuracy, and we show how they can be applied to various types of images to extract 2D, 3D, or even 4D deformation fields of a given surface. Examples are drawn from recent collaborative studies and include: (1) The study of the Icelandic Krafla rifting crisis that occurred from 1975 to 1984 where we used a combination of archived airborne photographs, declassified spy satellite imagery, and modern satellite acquisitions to propose a detailed 2D displacement field of the ground; (2) The estimation of glacial velocities from fast New Zealand glaciers using successive ASTER acquisitions; (3) The derivation of sand dunes migration rates; (4) The estimation of ocean swell velocity taking advantage of the short time delay between the acquisition of different spectral bands on the SPOT 5 satellite; (5) The derivation of the full 3D ground displacement field induced by the 2010 Mw 7.2 El Mayor-Cucapah Earthquake, as recorded from pre- and post-event lidar acquisitions; (6) And, the estimation of 2D in plane deformation of mechanical samples under stress in the lab. Finally, we conclude by highlighting the potential future and implication of applying such correlation techniques on a large scale to provide global monitoring of our environment.

  12. Two-dimensional incommensurately modulated structure of (Sr0.13Ca0. 87)2CoSi2O7 crystals.

    PubMed

    Bagautdinov, B; Hagiya, K; Kusaka, K; Ohmasa, M; Iishi, K

    2000-10-01

    The incommensurate structure of (Sr(0.13)Ca(0.87))(2)CoSi(2)O(7) at room temperature has been determined from single-crystal X-ray diffraction data. The compound has a non-centrosymmetric tetragonal basic cell of a = 7.8743 (4) and c = 5.0417 (2) A with the space group P4;2(1)m. The refinements of the basic structure converged to R = 0.038 for 757 main reflections. The two-dimensional incommensurate structure is characterized by the wavevectors q(1) = 0.286 (3)(a* + b*) and q(2) = 0.286 (3)(-a* + b*), where a*, b* are the reciprocal lattice vectors of the basic structure. With the (3 + 2)-dimensional superspace group P(p4mg)(P4;2(1)(m)), the refinements converged to R = 0.071 for 1697 observed reflections (757 main and 940 satellite reflections). The structure is described in terms of displacement of the atoms, rotation, distortion of CoO(4) and SiO(4) tetrahedra, and the partial ordering of the Sr and Ca atoms accompanied with the modulation. Correlated evolution of these features throughout the crystal gives rise to various oxygen coordination around Ca/Sr. Comparison of the derived modulated structure to that of Ca(2)CoSi(2)O(7) clarified that the partial substitution of Ca by large alkaline-earth atoms such as Sr should decrease the distortion of the polyhedra around the cations.

  13. Local interactions in peptides. 1H-1H, 13C-H coupling constants and calculations for the conformational analysis of N-acetyl-N'-methylamides of aliphatic amino acids.

    PubMed

    Fermandjian, S; Sakarellos, C; Aumelas, A; Toma, F; Gresh, N

    1990-05-01

    We report the results of a joint NMR and theoretical investigation devoted to the conformational properties of N-acetyl-N'-methylamides of aliphatic amino acids with side chains of increasing bulkiness: Gly, Ala, Leu, Ile, and tert.Leu. In this series, determination of the coupling constants 3JHNC alpha H together with the coupling constants 3JC'NC alpha H (thanks to specific carbon-13 labeling of the N-acetyl carbonyl group) led to the derivation of alternative A, B, and C parameters in a Karplus-type relation expressing the dependence of 3JC'NC alpha H upon the phi dihedral angle. The value of the latter is found to increase regularly following the increase of the side-chain bulkiness. The theoretical conformational analysis is performed by applying the SIBFA procedure, which uses empirical formulas based on ab initio SCF computations. The conformational energy maps illustrate the progressive distortion of the backbone conformation incurred in the series Gly to tert.Leu. Theoretical values computed for 3JHNC alpha H and 3JC'NC alpha H are found to be in a good quantitative agreement with the experimental ones.

  14. Isovalent substitutes play in different ways: Effects of isovalent substitution on the thermoelectric properties of CoSi0.98B0.02

    SciTech Connect

    Sun, Hui; Lu, Xu; Morelli, Donald T.

    2016-07-21

    Boron-added CoSi, CoSi0.98B0.02, possesses a very high thermoelectric power factor of 60 μW cm-1 K-2 at room temperature, which is among the highest power factors that have ever been reported for near-room-temperature thermoelectric applications. Since the electrical properties of this material have been tuned properly, isovalent substitution for its host atoms are intentionally employed to reduce the lattice thermal conductivity while maintaining the electronic properties unchanged. In our previous work, the effect of Rh substitution for Co atoms on the thermoelectric properties of CoSi0.98B0.02 has been studied. Here we present a study of the substitution of Ge for Si atoms in this compound. Even though Ge and Rh are isovalent with their corresponding host atoms, they play different roles in determining the electrical and thermal transport properties. Through the evaluation of the lattice thermal conductivity by the Debye approximation and the comparison between the high-temperature Seebeck coefficients, we propose that Rh substitution leads to a further overlapping of the conduction and the valence bands while Ge substitution only shifts the Fermi level upward into the conduction band. Lastly, our results show that the influence of isovalent substitution on the electronic structure cannot be ignored when the alloying method is used to improve thermoelectric properties.

  15. High-Resolution Pyrimidine- and Ribose-Specific 4D HCCH-COSY Spectra of RNA Using the Filter Diagonalization Method

    PubMed Central

    Douglas, Justin T.; Latham, Michael P.; Armstrong, Geoffrey S.; Bendiak, Brad; Pardi, Arthur

    2010-01-01

    NMR spectra of nucleic acids suffer from severe peak overlap, which complicates resonance assignments. 4D NMR experiments can overcome much of the degeneracy in 2D and 3D spectra; however, the linear increase in acquisition time with each new dimension makes it impractical to acquire high-resolution 4D spectra using standard Fourier Transform (FT) techniques. The Filter Diagonalization Method (FDM) is a numerically efficient algorithm that fits the entire multi-dimensional time-domain data to a set of multi-dimensional oscillators. Selective 4D constant-time HCCH-COSY experiments that correlate the H5-C5-C6-H6 base spin systems of pyrimidines or the H1′-C1′-C2′-H2′ spin systems of ribose sugars were acquired on the 13C-labeled Iron Responsive Element RNA. FDM-processing of these 4D experiments recorded with only 8 complex points in the indirect dimensions showed superior spectral resolution than FT-processed spectra. Practical aspects of obtaining optimal FDM-processed spectra are discussed. The results here demonstrate that FDM-processing can be used to obtain high-resolution 4D spectra on a medium sized RNA in a fraction of the acquisition time normally required for high-resolution, high-dimensional spectra. PMID:18626775

  16. Metabolic flux and metabolic network analysis of Penicillium chrysogenum using 2D [13C, 1H] COSY NMR measurements and cumulative bondomer simulation.

    PubMed

    van Winden, Wouter A; van Gulik, Walter M; Schipper, Dick; Verheijen, Peter J T; Krabben, Preben; Vinke, Jacobus L; Heijnen, Joseph J

    2003-07-05

    At present two alternative methods are available for analyzing the fluxes in a metabolic network: (1) combining measurements of net conversion rates with a set of metabolite balances including the cofactor balances, or (2) leaving out the cofactor balances and fitting the resulting free fluxes to measured (13)C-labeling data. In this study these two approaches are applied to the fluxes in the glycolysis and pentose phosphate pathway of Penicillium chrysogenum growing on either ammonia or nitrate as the nitrogen source, which is expected to give different pentose phosphate pathway fluxes. The presented flux analyses are based on extensive sets of 2D [(13)C, (1)H] COSY data. A new concept is applied for simulation of this type of (13)C-labeling data: cumulative bondomer modeling. The outcomes of the (13)C-labeling based flux analysis substantially differ from those of the pure metabolite balancing approach. The fluxes that are determined using (13)C-labeling data are shown to be highly dependent on the chosen metabolic network. Extending the traditional nonoxidative pentose phosphate pathway with additional transketolase and transaldolase reactions, extending the glycolysis with a fructose 6-phosphate aldolase/dihydroxyacetone kinase reaction sequence or adding a phosphoenolpyruvate carboxykinase reaction to the model considerably improves the fit of the measured and the simulated NMR data. The results obtained using the extended version of the nonoxidative pentose phosphate pathway model show that the transketolase and transaldolase reactions need not be assumed reversible to get a good fit of the (13)C-labeling data. Strict statistical testing of the outcomes of (13)C-labeling based flux analysis using realistic measurement errors is demonstrated to be of prime importance for verifying the assumed metabolic model. Copyright 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 83: 75-92, 2003.

  17. Development of a Standardized Methodology for the Use of COSI-Corr Sub-Pixel Image Correlation to Determine Surface Deformation Patterns in Large Magnitude Earthquakes.

    NASA Astrophysics Data System (ADS)

    Milliner, C. W. D.; Dolan, J. F.; Hollingsworth, J.; Leprince, S.; Ayoub, F.

    2014-12-01

    Coseismic surface deformation is typically measured in the field by geologists and with a range of geophysical methods such as InSAR, LiDAR and GPS. Current methods, however, either fail to capture the near-field coseismic surface deformation pattern where vital information is needed, or lack pre-event data. We develop a standardized and reproducible methodology to fully constrain the surface, near-field, coseismic deformation pattern in high resolution using aerial photography. We apply our methodology using the program COSI-corr to successfully cross-correlate pairs of aerial, optical imagery before and after the 1992, Mw 7.3 Landers and 1999, Mw 7.1 Hector Mine earthquakes. This technique allows measurement of the coseismic slip distribution and magnitude and width of off-fault deformation with sub-pixel precision. This technique can be applied in a cost effective manner for recent and historic earthquakes using archive aerial imagery. We also use synthetic tests to constrain and correct for the bias imposed on the result due to use of a sliding window during correlation. Correcting for artificial smearing of the tectonic signal allows us to robustly measure the fault zone width along a surface rupture. Furthermore, the synthetic tests have constrained for the first time the measurement precision and accuracy of estimated fault displacements and fault-zone width. Our methodology provides the unique ability to robustly understand the kinematics of surface faulting while at the same time accounting for both off-fault deformation and measurement biases that typically complicates such data. For both earthquakes we find that our displacement measurements derived from cross-correlation are systematically larger than the field displacement measurements, indicating the presence of off-fault deformation. We show that the Landers and Hector Mine earthquake accommodated 46% and 38% of displacement away from the main primary rupture as off-fault deformation, over a mean

  18. Stereoselective synthesis, spectral and antimicrobial studies of some cyanoacetyl hydrazones of 3-alkyl-2,6-diarylpiperidin-4-ones

    NASA Astrophysics Data System (ADS)

    Velayutham Pillai, M.; Rajeswari, K.; Vidhyasagar, T.

    2014-11-01

    A series of novel cyanoacetyl hydrazones of 3-alkyl-2,6-diarylpiperidin-4-ones were synthesized stereoselectively and characterized by IR, Mass, 1H NMR, 13C NMR, 1H-1H COSY and 1H-13C COSY spectra. The stereochemistry of the synthesized compounds was established using NMR spectra. Antimicrobial screening of the synthesized compounds revealed their antibacterial and antifungal potencies. Growth inhibition of Enterobacter Aerogenes by compound 15 was found to be superior to the standard drug.

  19. Characterization and thermal isomerization of (all-E)-lycopene.

    PubMed

    Takehara, Munenori; Nishimura, Masatoshi; Kuwa, Takahiro; Inoue, Yoshinori; Kitamura, Chitoshi; Kumagai, Tsutomu; Honda, Masaki

    2014-01-08

    A large amount of (all-E)-lycopene was successfully purified from tomato paste using an improved method that included a procedure to wash crystalline powder with acetone. The total yield of the pure (all-E) form was at least 30%. The melting point of (all-E)-lycopene was determined to be 176.35 °C by differential scanning calorimetry (DSC) measurements. Bathochromic shifts were observed in the absorption maxima of all solvents tested (at most a 36 nm shift for λ2 in carbon disulfide, as was observed in hexane) and were accompanied by absorbance decreases, namely, a hypochromic effect, showing a higher correlation between the position and the intensity of the main absorption bands. This bathochromic shift was dependent upon the polarizability of the solvent rather than its polarity. The structure of (all-E)-lycopene in CDCl3 and C6D6 was identified on the basis of one- and two-dimensional nuclear magnetic resonance (NMR) spectra, including (1)H and (13)C NMR, homonuclear correlation spectroscopy ((1)H-(1)H COSY), heteronuclear multiple-quantum coherence (HMQC), and heteronuclear multiple-bond connectivity (HMBC). The rate constants of the decrease in (all-E)-lycopene with hexane and benzene were calculated to be 3.19 × 10(-5) and 3.55 × 10(-5) s(-1), respectively. The equilibrium constants between (all-E) and (13Z) isomers were estimated to be 0.29 in hexane and 0.31 in benzene, respectively, from the point at which the amount of (13Z)-lycopene reached its maximum.

  20. Chemical Components from Aloe and their Inhibition of Indoleamine 2, 3-dioxygenase

    PubMed Central

    Sun, Ya Nan; Li, Lin Ying; Li, Wei; Kang, Jong Seong; Hwang, Inkyu; Kim, Young Ho

    2017-01-01

    Background: In Korea, Aloe is routinely ingested as a traditional medicine or as a component of health beverages. Objective: To research the inhibition of indoleamine 2, 3-dioxygenase (IDO) activities of components from Aloe. Materials and Methods: the compounds were isolated by a combination of silica gel and YMC Rp-18 column chromatography, and their structures were identified by analysis of spectroscopic data (1D, 2D-NMR, and MS). All of the isolated compounds were examined for their ability to inhibit IDO, which actively suppresses immune functions by catalyzing the rate limiting reaction in the conversion of tryptophan to kynurenine. Results: In this phytochemical study, 18 known compounds were isolated from aqueous dissolved Aloe exudates. All of the isolated compounds were examined for their ability to inhibit IDO activities for a series of anthraquinone derivatives (1-7) isolated from the Aloe extract; the IC50 values of these compounds ranged from 39.41 to 53.93 µM. Enzyme kinetic studies of their modes of inhibition indicated that all of the compounds were uncompetitive inhibitors. Conclusion: The aqueous dissolved Aloe exudate can be used as a source of novel natural IDO inhibitors and merit testing as therapeutic agents in the treatments of cancer and immunopathologic diseases, such as autoimmune, inflammatory, and allergic disorders. SUMMARY In this study, 18 known compounds were isolated from aqueous dissolved Aloe exudates. All of the isolated compounds were examined for their ability to inhibit indoleamine 2, 3-dioxygenase (IDO) activities for a series of anthraquinone derivatives (1−7) isolated from the Aloe extract. Abbreviation used: IDO: inhibit indoleamine 2, 3-dioxygenase, TMS: tetramethylsilane, HMQC: heteronuclear multiple quantum correlation, HMBC: heteronuclear multiple bond correlation, COSY: 1H-1H correlation spectroscopy, ESI-MS: Electrospray ionization mass spectrometry, DMSO: dimethyl sulfoxide PMID:28216884

  1. Characterization of a cinnamoyl derivative from broccoli (Brassica oleracea L. var. italica) florets.

    PubMed

    Survay, Nazneen Shaik; Kumar, Brajesh; Upadhyaya, Chandrama Prakash; Ko, Eunyoung; Lee, Choonghwan; Choi, Jung Nam; Yoon, Do-Young; Jung, Yi-Sook; Park, Se Won

    2010-12-01

    A new intact glucosinolate Cinnamoyl derivative [6'-O-trans-(4″- hydroxy cinnamoyl)-4-(methylsulphinyl) butyl glucosinolate] (A) has been isolated from Broccoli (Brassica oleracea L. var. italica) florets. The compound was isolated and characterized by LC, MS-ESI, FTIR, (1)H and (13)C NMR as well as (1)H-(1)H COSY, DEPT 135° spectrometric experiments.

  2. Triterpenoid saponins from Argania spinosa.

    PubMed

    Charrouf, Z; Wieruszeski, J M; Fkih-Tetouani, S; Leroy, Y; Charrouf, M; Fournet, B

    1992-06-01

    Five new oleanane saponins named arganine A, B, D, E and F and two known saponins: arganine C and mi-saponin A were isolated from the kernel of Argania spinosa. The structures of these saponins were elucidated by using 1H NMR, 1H-1H COSY NMR, 13C NMR, FAB mass spectrometry and chemical evidence.

  3. Spectroscopic characterization of the 1-substituted 3,3-diphenyl-4-(2'-hydroxyphenyl)azetidin-2-ones: Application of 13C NMR, 1H- 13C COSY NMR and mass spectroscopy

    NASA Astrophysics Data System (ADS)

    Singh, Girija S.; Pheko, Tshepo

    2008-08-01

    The article deals with spectroscopic characterization of azetidin-2-ones. The presence of substituents like hydroxyl, fluoro, methoxy and benzhydryl, etc., on the azetidin-2-one ring significantly affects the IR absorption and 13C NMR frequencies of the carbonyl group present in these compounds. The presence of an ester carbonyl group or too many methine protons in the molecule has been observed to limit the scope of IR and 1H NMR spectroscopy in unambiguous assignment of the structure. The application of 13C NMR, 2D NMR ( 1H- 13C COSY) and mass spectroscopy in characterization of complex azetidin-2-ones is discussed. An application of the latter two techniques is described in deciding unequivocally between an azetidin-2-one ring and chroman-2-one ring structure for the product obtained by treatment of the 1-substituted 3,3-diphenyl-4-[2'-( O-diphenylacyl)hydroxyphenyl]-2-azetidinones with ethanolic sodium hydroxide at room temperature.

  4. Search for η-mesic 4He in the dd →3He nπ0 and dd →3He pπ- reactions with the WASA-at-COSY facility

    NASA Astrophysics Data System (ADS)

    Adlarson, P.; Augustyniak, W.; Bardan, W.; Bashkanov, M.; Bergmann, F. S.; Berłowski, M.; Bhatt, H.; Bondar, A.; Büscher, M.; Calén, H.; Ciepał, I.; Clement, H.; Czerwiński, E.; Demmich, K.; Engels, R.; Erven, A.; Erven, W.; Eyrich, W.; Fedorets, P.; Föhl, K.; Fransson, K.; Goldenbaum, F.; Goswami, A.; Grigoryev, K.; Gullström, C.-O.; Heijkenskjöld, L.; Hejny, V.; Hüsken, N.; Jarczyk, L.; Johansson, T.; Kamys, B.; Kelkar, N. G.; Kemmerling, G.; Khatri, G.; Khoukaz, A.; Khreptak, O.; Kirillov, D. A.; Kistryn, S.; Kleines, H.; Kłos, B.; Krzemień, W.; Kulessa, P.; Kupść, A.; Kuzmin, A.; Lalwani, K.; Lersch, D.; Lorentz, B.; Magiera, A.; Maier, R.; Marciniewski, P.; Mariański, B.; Morsch, H.-P.; Moskal, P.; Ohm, H.; Perez del Rio, E.; Piskunov, N. M.; Prasuhn, D.; Pszczel, D.; Pysz, K.; Pyszniak, A.; Ritman, J.; Roy, A.; Rudy, Z.; Rundel, O.; Sawant, S.; Schadmand, S.; Schätti-Ozerianska, I.; Sefzick, T.; Serdyuk, V.; Shwartz, B.; Sitterberg, K.; Skorodko, T.; Skurzok, M.; Smyrski, J.; Sopov, V.; Stassen, R.; Stepaniak, J.; Stephan, E.; Sterzenbach, G.; Stockhorst, H.; Ströher, H.; Szczurek, A.; Trzciński, A.; Varma, R.; Wolke, M.; Wrońska, A.; Wüstner, P.; Yamamoto, A.; Zabierowski, J.; Zieliński, M. J.; Złomańczuk, J.; Żuprański, P.; Żurek, M.

    2017-03-01

    The search for 4He- η bound states was performed with the WASA-at-COSY facility via the measurement of the excitation function for the dd →3He nπ0 and dd →3He pπ- processes. The deuteron beam momentum was varied continuously between 2.127 GeV/c and 2.422 GeV/c, corresponding to the excess energy for the dd →4He η reaction ranging from Q = - 70 MeV to Q = 30 MeV. The luminosity was determined based on the dd →3He n reaction and the quasi-free proton-proton scattering via dd → ppnspectatornspectator reactions. The excitation functions, determined independently for the measured reactions, do not reveal a structure which could be interpreted as a narrow mesic nucleus. Therefore, the upper limits of the total cross sections for the bound state production and decay in dd →(4He- η) bound →3He nπ0 and dd →(4He- η) bound →3He pπ- processes were determined taking into account the isospin relation between the both of the considered channels. The results of the analysis depend on the assumptions of the N*(1535) momentum distribution in the anticipated mesic-4He. Assuming, as in the previous works, that this is identical with the distribution of nucleons bound with 20 MeV in 4He, we determined that (for the mesic bound state width in the range from 5 MeV to 50 MeV) the upper limits at 90% confidence level are about 3 nb and about 6 nb for nπ0 and pπ- channels, respectively. However, based on the recent theoretical findings of the N*(1535) momentum distribution in the N*-3He nucleus bound by 3.6 MeV, we find that the WASA-at-COSY detector acceptance decreases and hence the corresponding upper limits are 5 nb and 10 nb for nπ0 and pπ- channels respectively.

  5. Alkaloids from Hippeastrum morelianum Lem. (Amaryllidaceae).

    PubMed

    Giordani, Raquel B; de Andrade, Jean P; Verli, Hugo; Dutilh, Julie H; Henriques, Amélia T; Berkov, Strahil; Bastida, Jaume; Zuanazzi, José Angelo S

    2011-10-01

    The Amaryllidaceae family has proven to be a rich source of active molecules. As part of an ongoing project, we report a phytochemical study of Hippeastrum morelianum (Amaryllidaceae), from which we have isolated two homolycorine-type alkaloids, the new 2α,7-dimethoxyhomolycorine (1) and the poorly described candimine (2), as well as six known alkaloids: tazettine, pretazettine, 3-epimacronine, haemanthamine, hamayne and trisphaeridine. For reference purposes, the NMR of the isolated compounds was unequivocally described, based on 2D NMR measurements including (1)H-(1)H COSY, (1)H-(1)H NOESY, HSQC and HMBC.

  6. Structural and spectroscopic investigation on a new potentially bioactive di-hydrazone containing thiophene heterocyclic rings

    NASA Astrophysics Data System (ADS)

    Nogueira, Vanessa de S.; Ramalho Freitas, Maria Clara; Cruz, Wellington S.; Ribeiro, Tatiana S.; Resende, Jackson A. L. C.; Rey, Nicolás A.

    2016-02-01

    Hydrazones and several substituted hydrazones are associated with a broad spectrum of biological activities, as well as compounds containing the thiophene ring. In this context, a novel di-hydrazone derived from 2-thiophenecarboxylic acid hydrazide was synthesized and completely characterized by elemental analysis, XRD, FT-IR, Raman and UV-Vis spectroscopies, thermogravimetry, 1H NMR, 1H-1H COSY and 1H-1H ROESY. A preliminary in silico pharmacological evaluation was also performed in order to assess the performance of the new compound regarding some molecular properties relevant for a drug's pharmacokinetics in the human body.

  7. Studies on the solution conformation of human thioredoxin using heteronuclear sup 15 N- sup 1 H nuclear magnetic resonance spectroscopy

    SciTech Connect

    Forman-Kay, J.D. Yale Univ., New Haven, CT ); Gronenborn, A.M.; Kay, L.E.; Clore, G.M. ); Wingfield, P.T. )

    1990-02-13

    The solution conformation of uniformly labeled {sup 15}N human thioredoxin has been studied by two-dimensional heteronuclear {sup 15}N-{sup 1}H nuclear magnetic resonance spectroscopy. Assignments of the {sup 15}N resonances of the protein are obtained in a sequential manner using heteronuclear multiple quantum coherence (HMQC), relayed HMQC-correlated (COSY), and relayed HMQC-nuclear Overhauser (NOESY) spectroscopy. Values of the {sup 3}J{sub HN{alpha}} splittings for 87 of the 105 residues of thioredoxin are extracted from a variant of the HMQC-COSY experiment, known as HMQC-J, and analyzed to give accurate {sup 3}J{sub HN{alpha}} coupling constants. In addition, long-range C{sub {alpha}}H(i)-{sup 15}N(i+1) scalar connectivities are identified by heteronuclear multiple bond correlation (HMBC) spectroscopy. The presence of these three-bond scalar connectivities in predominantly {alpha}-helical regions correlates well with the secondary structure determined previously from a qualitative analysis of homonuclear nuclear Overhauser data suggesting that this technique may provide additional information for secondary structure determination a priori. The accuracy with which {sup 3}J{sub HN{alpha}} coupling constants can be obtained from the HMQC-J experiment permits a more precise delineation of the beginnings and ends of secondary structural elements of human thioredoxin and of irregularities in these elements.

  8. A new sweet dihydrochalcone-glucoside from leaves of Lithocarpus pachyphyllus (Kurz) Rehd. (Fagaceae).

    PubMed

    Qin, Xiang-Dong; Liu, Ji-Kai

    2003-01-01

    A new sweet dihydrochalcone-glucoside, trilobatin 2"-acetate (1), was isolated from the leaves of Lithocarpus pachyphyllus, together with phlorizin and trilobatin. The structures were established by spectroscopic methods, including one- and two-dimensional NMR (COSY, HMQC and HMBC).

  9. New indole alkaloid from Peschiera affinis (Apocynaceae).

    PubMed

    Santos, Allana Kellen L; Machado, Luciana L; Bizerra, Ayla Marcia C; Monte, Francisco José Q; Santiago, Gilvandete M P; Braz-Filho, Raimundo; Lemos, Telma L G

    2012-06-01

    A new indole alkaloid of the pyridocarbazole type, named 6N-hydroxy-olivacine, and two known compounds, 2N-oxide-olivacine and olivacine, were isolated from roots of Peschiera affinis. The structures of the compounds were determined by spectroscopic {IR and extensive NMR (COSY, HMQC, HMBCand NOESY)} and EIMS analysis.

  10. Assignment of NMR data and relative stereochemistry determination of paraconic acid derivatives

    NASA Astrophysics Data System (ADS)

    Rodrigues, Shirley Muniz Machado; Nardini, Viviani; Moral, Raphael Fernando; Constantino, Mauricio Gomes; da Silva, Gil Valdo José

    2013-12-01

    γ-Butyrolactones 4a1, 4a2, 4b1 and 4b2 were carefully studied through NMR experiments. 1H NMR, 13C {1H} NMR, COSY, HMQC, HMBC and J-res experiments were performed to provide the needed structure information. NOE between protons distributed around the stereocenters were thus used to determine the relative configuration of the molecules.

  11. Chemical constituents of Tephrosia purpurea.

    PubMed

    Khalafalah, Ali K; Yousef, Afifi H; Esmail, Abeer M; Abdelrazik, Mohamed H; Hegazy, Mohamed E F; Mohamed, Abou-El-Hamd H

    2010-03-01

    In continuation of our chemical investigation on some medicinal plants of the genus Tephrosia, reinvestigation of the methylenechloride/methanol (1:1) extract of the aerial parts of Tephrosia purpurea yielded an aromatic ester 1, a sesquiterpene 2 and prenylated flavonoid 3. The structures of the compounds were established by comprehensive NMR studies, including DEPT, COSY, NOE, HMQC, HMBC, EIMS and CIMS.

  12. Biotransformation of glabratephrin, a rare type of isoprenylated flavonoids, by Aspergillus niger.

    PubMed

    Mohamed, Abou-El-Hamd H; Khalafallah, Ali K; Yousof, Afifi H

    2008-01-01

    Microbial transformation of glabratephrin, the major isolated compound from Tephrosia purpurea, afforded pseudosemiglabrin. The formation of the transformed compound seems to be performed via ring opening-closure of a five-membered ring causing transformation from a spiro into a fused system. The structure of the transformed compound was determined by comprehensive NMR studies, including DEPT, COSY, HMQC, NOE and MS.

  13. Isolation and structural elucidation of chemical constituents from the fruits of Morinda citrifolia Linn.

    PubMed

    Siddiqui, Bina S; Sattar, Fouzia A; Ahmad, Fayaz; Begum, Sabira

    2007-08-01

    The fruits of Morinda citrifolia, Linn. afforded a new constituent, morinaphthalenone (1), and three known constituents, scopoletin (2), 1, 3-dimethoxy-anthraquinone (3) and 1, 2-dihydroxy-anthraquinone (4). The structures of these isolated compounds were determined by spectroscopic methods, including 1D- and 2D-NMR (COSY-45, HMQC, HMBC) techniques, as well as by comparison with published values.

  14. Simulation of 2D NMR Spectra of Carbohydrates Using GODESS Software.

    PubMed

    Kapaev, Roman R; Toukach, Philip V

    2016-06-27

    Glycan Optimized Dual Empirical Spectrum Simulation (GODESS) is a web service, which has been recently shown to be one of the most accurate tools for simulation of (1)H and (13)C 1D NMR spectra of natural carbohydrates and their derivatives. The new version of GODESS supports visualization of the simulated (1)H and (13)C chemical shifts in the form of most 2D spin correlation spectra commonly used in carbohydrate research, such as (1)H-(1)H TOCSY, COSY/COSY-DQF/COSY-RCT, and (1)H-(13)C edHSQC, HSQC-COSY, HSQC-TOCSY, and HMBC. Peaks in the simulated 2D spectra are color-coded and labeled according to the signal assignment and can be exported in JCAMP-DX format. Peak widths are estimated empirically from the structural features. GODESS is available free of charge via the Internet at the platform of the Carbohydrate Structure Database project ( http://csdb.glycoscience.ru ).

  15. Sesquiterpene constituents from the soft coral Sinularia nanolobata.

    PubMed

    Ngoc, Ninh Thi; Huong, Pham Thi Mai; Thanh, Nguyen Van; Cuong, Nguyen Xuan; Nam, Nguyen Hoai; Thung, Do Cong; Kiem, Phan Van; Minh, Chau Van

    2017-02-28

    Using various chromatographic separations, four sesquiterpenes (1-4), including two new compounds, nanolobatols A and B (1 and 2), were isolated from the Vietnamese soft coral Sinularia nanolobata. Their structures were determined on the basis of spectroscopic data ((1)H and (13)C NMR, HSQC, HMBC, (1)H-(1)H COSY, NOESY and FT-ICR-MS) and by comparison with the literature values. The cytotoxic activity of isolated compounds against a panel of eight human cancer cell lines was also evaluated.

  16. Structure elucidation and complete NMR spectral assignments of four new diterpenoids from Smallantus sonchifolius.

    PubMed

    Dou, De-Qiang; Tian, Fang; Qiu, Ying-Kun; Kang, Ting-Guo; Dong, Feng

    2008-08-01

    Four new diterpenoids, named smaditerpenic acid A-D, together with five known compounds, were isolated from the H(2)O extract of the leaves of Smallantus sonchifolius (yacon) cultivated in Liaoning, China and their structures were elucidated on the basis of one- and two-dimensional NMR (including (1)H, (13)C-NMR, (1)H-(1)H COSY, HSQC, TOCSY, HMBC, and ROESY), electrospray ionization mass spectrometry (ESI-MS), and chemical methods.

  17. The structure of the O-polysaccharide from the lipopolysaccharide of Providencia stuartii O47.

    PubMed

    Ovchinnikova, Olga G; Kocharova, Nina A; Bakinovskiy, Leon V; Torzewska, Agnieszka; Shashkov, Alexander S; Knirel, Yuriy A; Rozalski, Antoni

    2004-10-20

    The O-polysaccharide was obtained by mild acid degradation of the lipopolysaccharide of Providencia stuartii O47:H4, strain 3646/51. Studies by sugar and methylation analyses along with Smith degradation and 1H and 13C NMR spectroscopy, including two-dimensional 1H,1H COSY, TOCSY, ROESY and H-detected 1H,13C HSQC and HMBC experiments, showed that the polysaccharide has a branched hexasaccharide repeating unit with the following structure: [carbohydrate structure: see text

  18. Structural determination of two new steroidal saponins from Smilax china.

    PubMed

    Huang, Hui-Lian; Liu, Rong-Hua; Shao, Feng

    2009-09-01

    Two new steroidal saponins (1 and 2) were isolated from the BuOH fraction of the 70% EtOH extract of the tubes of Smilax china, together with four known analogues, 3-6. The structures of the new compounds were elucidated by means of chemical evidence and spectroscopic analyses, including HR-MS, IR, (1)H- and (13)C-NMR, and 2D experiments ((1)H-(1)H COSY, HSQC and HMBC).

  19. A new lyoniresinol derivative from Smilax microphylla.

    PubMed

    Liu, Li-Sha; Huang, Hui-Lian; Liu, Rong-Hua; Ren, Gang; Shao, Feng; Ye, Yao-Hui; Lin, Tao

    2013-01-01

    A new lignan, lyoniresinol-9-O-8"-syringylglycerol ether (1), together with five known compounds, piceatannol (2), resveratrol (3), oxyresveratrol (4), quercetin-3'-glucoside (5) and diosgenin (6) were isolated from the rhizomes of Smilax microphylla. The structure of the new compound was determined by means of chemical evidence and 1D-and 2D-NMR (1H, 13C, HSQC, HMBC, 1H-1H COSY and NOESY) spectroscopic analysis and HR-ESI-MS.

  20. Clitolactone: a banana slug antifeedant from Clitocybe flaccida.

    PubMed

    Wood, William F; Clark, Thomas J; Bradshaw, Debra E; Foy, Brian D; Largent, David L; Thompson, Bradley L

    2004-01-01

    Clitolactone, 5-(chloromethyl)-3-methyl-2(5H)-furanone, was isolated from sporocaps of the mushroom Clitocybe flaccida. The structure was determined by HRMS, EIMS, (1)H & (13)C NMR, 2D (1)H-(13)C COSY and (1)H-(1)H COSY. This mushroom is not eaten by the banana slug Ariolimax columbianus (Gould), a mycophagist from the temperate rain forests of the Pacific Northwest. Clitolactone acts as an antifeedant because these slugs rejected 1.0 cm(2) pieces of lettuce treated with 25 μg of clitolactone.

  1. Quantitative time- and frequency-domain analysis of the two-pulse COSY revamped by asymmetric Z-gradient echo detection NMR experiment: Theoretical and experimental aspects, time-zero data truncation artifacts, and radiation damping.

    PubMed

    Kirsch, Stefan; Hull, William E

    2008-07-28

    The two-pulse COSY revamped by asymmetric Z-gradient echo detection (CRAZED) NMR experiment has the basic form 90 degrees -Gdelta-t(rec)-beta-nGdelta-t(rec)-FID, with a phase-encoding gradient pulse G of length delta applied during the evolution time tau for transverse magnetization, readout pulse beta, rephasing gradient nGdelta, and recovery time t(rec) prior to acquisition of the free-induction decay. Based on the classical treatment of the spatially modulated dipolar demagnetizing field and without invoking intermolecular multiple-quantum coherence, a new formulation of the first-order approximation for the theoretical solution of the nonlinear Bloch equations has been developed. The nth-order CRAZED signal can be expressed as a simple product of a scaling function C(n)(beta,tau) and a signal amplitude function A(n)(t), where the domain t begins immediately after the beta pulse. Using a single-quantum coherence model, a generalized rf phase shift function has also been developed, which explains all known phase behavior, including nth-order echo selection by phase cycling. Details of the derivations are provided in two appendices as supplementary material. For n>1, A(n)(t) increases from zero to a maximum value at t=t(max) before decaying and can be expressed as a series of n exponential decays with antisymmetric binomial coefficients. Fourier transform gives an antisymmetric binomial series of Lorentzians, where the composite lineshape exhibits negative wings, zero integral, and a linewidth that decreases with n. Analytical functions are presented for t(max) and A(n)(t(max)) and for estimating the maximal percent error incurred for A(n)(t(max)) when using the first-order model. The preacquisition delay Delta=delta+t(rec) results in the loss of the data points for t=0 to Delta. Conventional Fourier transformation produces time-zero truncation artifacts (reduced negative wing amplitude, nonzero integral, and reduced effective T(2) ( *)), which can be avoided by

  2. Spasmolytic effects of Scrophularia nodosa extract on isolated rabbit intestine.

    PubMed

    Ahmad, Mansoor; Muhammad, Noor; Mehjabeen; Jahan, Noor; Ahmad, Manzoor; Obaidullah; Qureshi, Mahmood; Jan, Syed Umar

    2012-01-01

    Scrophularia nodosa (figwort), an indigenous medicinal plant grows in moist and cultivated waste ground. It contains saponins, cardioactive glycosides, flavonoids, resin, sugar and organic acids. It is traditionally used for anti-inflammatory purpose and in skin disorders. It has diuretic and cardiac stimulant properties. The present studies were carried out on crude extract of Scrophularia nodosa and its n-hexane, chloroform, ethyl acetate, n-butanol and aqueous fractions. During phytochemical studies seven known compounds of flavonoid nature were isolated from the chloroform fraction of crude extract of S. nodosa. The structures of these compounds were elucidated by spectroscopic (UV, IR, Mass (EIMS, HREIMS) and NMR ((1)H-NMR, (13)C-NMR, DEPT, and (1)H-(1)H, COSY, HMQC, HMBC and NOESY) techniques. Compound 1 was identified as 5, 4`-hydroxy-3, 6, 7-trimethoxyflavone, compound 2 as 5-hydroxy-3,6,7,4'-tetramethoxyflavone, compound 3 as Centaurein, compound 4 as 5-hydroxy-7,8,2',3',4'-pentamethoxyflavone (Serpyllin), compound 5 as Kaempferol 7-O-α-L-rhamnopyranoside, compound 6 as sakuranetin 4'-O (6''-O-α-L-rhamnopyranosyl)-β-D-glucopyranoside (Vitexoside) and compound 7 as Spinoside. Crude extract and its fractions were tested on isolated rabbit intestine (in vitro) for their effects. The results of crude extract and its fractions in different doses showed the decrease in normal movement of the smooth muscles of rabbit intestine (jejunum). The chloroform fraction showed maximum relaxant effect (77.37%) at 15mg/ml dose and aqueous fraction showed 38.56% spasmogenic response which was not present in the crude extract. Further study was carried out on different fractions to investigate the possible mechanism of action of S. nodosa extract. For this purpose spasmolytic effect of different fractions were compared with agonist and antagonist activities of standard drugs including adrenaline, atropine andacetylcholine (1x10(-2), 1x10(-4) and 10(-6) M conc.). It is

  3. Dihydrofolate reductase: Sequential resonance assignments using 2D and 3D NMR and secondary structure determination in solution

    SciTech Connect

    Carr, M.D.; Birdsall, B.; Jimenez-Barbero, J.; Polshakov, V.I.; McCormick, J.E.; Feeney, J.; Frenkiel, T.A.; Bauer, C.J. ); Roberts, G.C.K. )

    1991-06-25

    Three-dimensional (3D) heteronuclear NMR techniques have been used to make sequential {sup 1}H and {sup 15}H resonance assignments for most of the residues of Lactobacillus casei dihydrofolate reductase (DHFR), a monomeric protein of molecular mass 18,300 Da. A uniformly {sup 15}N-labeled sample of the protein was prepared and its complex with methotrexate (MTX) studied by 3D {sup 15}N/{sup 1}H nuclear Overhauserheteronuclear multiple quantum coherence (NOESY-HMQC), Harmann-Hahn-heteronuclear multiple quantum coherence (HOHAHA-HMQC), and HMQC-NOESY-HMQC experiments. These experiments overcame most of the spectral overlap problems caused by chemical shift degeneracies in 2D spectra and allowed the {sup 1}H-{sup 1}H through-space and through-bond connectivities to be identified unambiguously, leading to the resonance assignments. The novel HMQC-NOESY-HMQC experiment allows NOE cross peaks to be detected between NH protons even when their {sup 1}H chemical shifts are degenerate as long as the amide {sup 15}N chemical shifts are nondegenerate. The 3D experiments, in combination with conventional 2D NOESY, COSY, and HOHAHA experiments on unlabelled and selectively deuterated DHFR, provide backbone assignments for 146 of the 162 residues and side-chain assignments for 104 residues of the protein. Data from the NOE-based experiments and identification of the slowly exchanging amide protons provide detailed information about the secondary structure of the binary complex of the protein with methotrexate.

  4. Chemical constituents of Tephrosia purpurea

    PubMed Central

    Khalafalah, Ali K.; Yousef, Afifi H.; Esmail, Abeer M.; Abdelrazik, Mohamed H.; Hegazy, Mohamed E. F.; Mohamed, Abou-El-Hamd H.

    2010-01-01

    In continuation of our chemical investigation on some medicinal plants of the genus Tephrosia, reinvestigation of the methylenechloride/methanol (1:1) extract of the aerial parts of Tephrosia purpurea yielded an aromatic ester 1, a sesquiterpene 2 and prenylated flavonoid 3. The structures of the compounds were established by comprehensive NMR studies, including DEPT, COSY, NOE, HMQC, HMBC, EIMS and CIMS. PMID:21808544

  5. Cichorin A: a new benzo-isochromene from Cichorium intybus.

    PubMed

    Hussain, Hidayat; Hussain, Javid; Saleem, Muhammad; Miana, Ghulam Abbas; Riaz, Muhammad; Krohn, Karsten; Anwar, Saeed

    2011-06-01

    One new benzo-isochromene, named cichorin A (1), together with three known compounds oleanolic acid, β-sitosterol, and β-sitosterol glucopyranoside, was isolated from Cichorium intybus. The structure of the new compound was elucidated by detailed spectroscopic analysis such as (1)H, (13)C NMR, COSY, HMQC, HMBC, and HR-EI-MS. Relative configuration of asymmetric centers of cichorin A (1) was determined by the analysis of the (1)H NMR coupling constants together with the NOESY experiment.

  6. Chemical analysis of an immunostimulating (1→4)-, (1→6)-branched glucan from an edible mushroom, Calocybe indica.

    PubMed

    Mandal, Eshita Kar; Maity, Kousik; Maity, Saikat; Gantait, Sanjoy K; Behera, Birendra; Maiti, Tapas K; Sikdar, Samir R; Islam, Syed S

    2012-01-10

    An immunostimulating water-soluble glucan was isolated from hot aqueous extract of fruit bodies of an edible mushroom Calocybe indica. Structural investigation of the glucan was carried out using acid hydrolysis, methylation analysis, and NMR studies ((1)H, (13)C, DEPT-135, TOCSY, DQF-COSY, NOESY, ROESY, HMQC, and HMBC). On the basis of above-mentioned experiments, the structure of the repeating unit of the polysaccharide was established as [see figure in text]. This glucan stimulated the splenocytes and thymocytes.

  7. A new dihydrofuranocoumarin from Opopanax hispidus (Friv.) Griseb.

    PubMed

    Ghasemi, Sabrieh; Habibi, Zohreh

    2014-01-01

    Phytochemical investigation of chloroform extract of the aerial parts of Opopanax hispidus afforded a new dihydrofuranocoumarin, 3'-isobutyryl-3'-hydroxymarmesin (1a), together with six known coumarins, oreoselon, peucedanin, officinalin, smirniorin, 4'-acetyl-3'-isobutyryl-3'-hydroxymarmesin and 3'-hydroxyprantschimgin. The structures of the compounds were determined by their comprehensive spectroscopic analysis (IR, EI-MS, (1)H NMR, (13)C NMR, HMBC, COSY, HMBC and HMQC), elemental analysis and comparison with literature data.

  8. One new triterpene ester from Nepeta suavis.

    PubMed

    Hussain, Javid; Khan, Farman Ullah; Ur Rehman, Najeeb; Ullah, Riaz; Mohmmad, Zia; Tasleem, S; Naeem, A; Shah, M Raza

    2009-12-01

    One new tetracyclic triterpene ester (1) has been isolated from the chloroform-soluble portion of the whole plant of Nepeta suavis along with two known compounds, namely artemetin (2) and jaceidin (3). The structures of the isolated compounds were assigned on the basis of their (1)H and (13)C NMR spectra including two-dimensional NMR techniques such as COSY, HMQC, and HMBC experiments and comparison with the literature data.

  9. New cytotoxic prostanoids from Taiwanese soft coral Clavularia viridis.

    PubMed

    Shen, Ya-Ching; Lo, Kuang-Liung; Chang, Jiun-Yang; Lin, Yun-Sheng; Mendbayar, Khongorzul; Kuo, Yao-Haur; Lin, Yu-Chi

    2010-11-01

    Chemical investigation of the AcOEt/MeOH extract of Clavularia viridis collected in Taiwan has afforded four new prostanoids, named claviridins A-D (1-4, resp.). The structures of compounds 1-4 were determined on the basis of 1D- and 2D-NMR techniques, including COSY, HMQC, HMBC, and NOESY experiments. Pharmacological studies revealed that compounds 1-4 exhibited potent cytotoxicity against human cancer cells.

  10. A New Cucurbitane Glycoside from Siraitia grosvenorii.

    PubMed

    Chaturvedula, Venkata Sai Prakash; Meneni, Srinivasa Rao

    2015-09-01

    A systematic phytochemical study of the commercial extract of Luo Han Guo (Siraitia grosvenorii) resulted in the isolation of an additional minor new cucurbitane glycoside, mogroside V Al (1). The structure of the new compound was characterized on the basis of 1D (1H and 13C NMR) and 2D (COSY, HMQC, HMBC and NOESY) NMR and high resolution mass spectral (HRMS) data, as well as hydrolysis studies.

  11. General occurrence of the glucosinolate glucocochlearin within the Cochlearia genus.

    PubMed

    Dauvergne, Xavier; Cérantola, Stéphane; Salaün, Stéphanie; Magné, Christian; Kervarec, Nelly; Bessières, Marie-Anne; Deslandes, Eric

    2006-09-04

    A natural compound, glucocochlearin, was isolated from the aerial parts of 10 different Cochlearia species. The purification of this compound was achieved through HPLC. The identity of the product was established mainly on the basis of spectroscopic NMR (1H, 13C, COSY, TOCSY, HMQC, HMBC, J-MOD) and high resolution mass spectroscopy data. This compound can be considered as a chemomarker of the genus Cochlearia.

  12. Alkaloids from Fissistigma latifolium (Dunal) Merr.

    PubMed

    Alias, Asmah; Hazni, Hazrina; Jaafar, Faridahanim Mohd; Awang, Khalijah; Ismail, Nor Hadiani

    2010-06-24

    A phytochemical study of the bark of Fissistigma latifolium (Annonaceae) yielded a new aporphine alkaloid, (-)-N-methylguattescidine (1), and eight known alkaloids: liriodenine (2), oxoxylopine (3), (-)-asimilobine (4), dimethyltryptamine (5), (-)-remerine (6), (-)-anonaine (7), columbamine (8) and lysicamine (9). The compounds were isolated using various chromatographic methods and structural elucidation was accomplished by means of spectroscopic methods, notably 1D-NMR ((1)H, (13)C, DEPT), 2D-NMR (COSY, HMQC, HMBC), UV, IR and MS.

  13. A New Sucrase Enzyme Inhibitor from Azadirachta indica.

    PubMed

    Abdelhady, Mohamed I S; Shaheen, Usama; Bader, Ammar; Youns, Mahmoud A

    2016-05-01

    Sucrase enzyme inhibitor considered as an oral anti-diabetic therapy that delays the absorption of eaten carbohydrates, reducing the postprandial glucose and insulin peaks to reach normoglycemia. Chromatographic fractionation of the hydroalcoholic extract of leaves of Azadirachta indica growing in KSA, followed by in-vitro assay of sucrase enzyme inhibition activity. This investigation led to the isolation of a new remarkable sucrase enzyme inhibitor; 4'-methyl Quercetin-7-O-β-D-glucuronopyranoside (1) alongside with four known compounds; 2,3-hexahydroxydiphenoyl-(α/β)-D-(4)C1-glucopyranose (2), Avicularin (3), Castalagin (4) and Quercetin-3-O-glucoside (5). The structure of the new compound (1) was elucidated on the basis of its spectral data, including ESI-MS, UV, (1)H NMR, (13)C NMR, (1)H-(1)H COSY, HSQC, NOESY and HMBC. Under the assay conditions, hydroalcoholic extract of A. indica and compounds 1-5 exhibited significant sucrase enzyme inhibitory activity. Chromatographic fractionation of the hydroalcoholic extract of leaves of Azadirachta indica, led to the Isolation of a new flavonoid glycoside named 4'-methyl Quercetin-7-O-β-D-glucuronopyranoside, alongside to other 4 known polyphenols. The hydroalcoholic extract as well as the isolated compounds exhibited significant sucrase enzyme inhibitory activity. Abbreviations used: ESI-MS; electrospray ionization-mass spectrometry, UV; ultraviolet, NMR; nuclear magnetic resonance, 1H-1H COSY; 1H-1H correlation spectroscopy, NOESY; nuclear overhauser effect spectroscopy, and HSQC; heteronuclear multiple bond correlation. A. indica; Azadirachta indica.

  14. 3-Desoxyanthocyanidins from Arrabidaea chica.

    PubMed

    Zorn, B; García-Piñeres, A J; Castro, V; Murillo, R; Mora, G; Merfort, I

    2001-04-01

    The new 3-desoxyanthocyanidins 6,7,3'-trihydroxy-5,4'-dimethoxy-flavylium and 6,7,3',4'-tetrahydroxy-5-methoxy-flavylium and the known 6,7-dihydroxy-5,4'-dimethoxy-flavylium (Carajurin) were isolated by bioguided fractionation from the leaves of Arrabidaea chica, with transcription factor NF-kappaB as target. The structure of Carajurone was revised to be 6,7,4'-trihydroxy-5-methoxy-flavylium. Additionally, the flavone acacetin was found. All structures were mainly established on the basis of MS- and NMR data (1H, 1H-1H COSY and partly 13C, GHMQCR and GHSQCR). Carajurin, which failed to give a positive result in the DPPH TLC assay completely inhibited NF-kappaB, but not NF-AT at a 500 microM concentration.

  15. An efficient procedure for assignment of the proton, carbon and nitrogen resonances in 13C/15N labeled nucleic acids.

    PubMed

    Nikonowicz, E P; Pardi, A

    1993-08-20

    An efficient method is presented for the assignment of the proton, carbon, and nitrogen resonances in the NMR spectra of isotopically labeled nucleic acids. The assignment strategy starts by identifying all protons and carbons belonging to the same sugar ring through application of a set of 2D or 3D heteronuclear HCCH NMR experiments. Next the individual sugar rings are connected to their corresponding bases through intra-residue 1H-1H nuclear Overhauser effects (NOEs) observed in a 3D (1H, 13C, 1H) NOESY-HMQC experiment. Sequential NOE connectivities observed in this experiment are then used to assign each residue in the nucleotide sequence. The imino protons and nitrogens, and the cytidine amino protons and nitrogens, are assigned by 2D (15N, 1H) HMQC and 3D (1H, 15N, 1H) NOESY-HMQC experiments in H2O. This assignment procedure is illustrated on the 99% 13C/15N labeled RNA duplex r(GGCGCUUGCGUC)2. The application of these multi-dimensional heteronuclear magnetic resonance experiments enormously simplifies the resonance assignment of nucleic acids and allows assignment of many more protons, carbons and nitrogens than was possible using standard techniques on unlabeled molecules. Since a larger percentage of the protons can now be assigned by these experiments, much more NMR structural information can be obtained which will significantly extend the size limit for solution structure determinations of RNAs.

  16. Structural study of (±) alkyl 3-hydroxy-1-azabicyclo[2.2.2]octane-3-carboxylates

    NASA Astrophysics Data System (ADS)

    Arias-Pérez, M. S.; Cosme, A.; Gálvez, E.; Sanz-Aparicio, J.; Fonseca, I.; Bellanato, J.

    2003-01-01

    A series of α-hydroxyesters derived from (±) 3-hydroxy-1-azabicyclo[2.2.2]octane-3-carboxylic acid was synthesised and studied by IR and NMR spectroscopy. The combined use of 1H- 1H COSY and 1H- 13C correlation spectra of these compounds helped in the unambiguous assignments of the bicyclic carbon and proton resonances. The crystal structure of ethyl (±) 3-hydroxy-1-azabicyclo[2.2.2]octane-3-carboxylate was determined by X-ray diffraction.

  17. Identification, isolation and characterization of a new degradation product in sultamicillin drug substance.

    PubMed

    Kumar, Vundavilli Jagadeesh; Gupta, P Badarinadh; Kumar, K S R Pavan; Ray, Uttam Kumar; Sreenivasulu, B; Kumar, G S Siva; Rao, K Ranga; Sharma, Hemant Kumar; Mukkanti, K

    2011-02-20

    A new degradant of sultamicillin drug substance was found during the gradient reverse phase HPLC analysis of stability storage samples. The level of this degradant impurity was observed up to 1.0%. The impurity (formaldehyde adduct with 5-oxo-4-phenylimidazolidin-1-yl moiety) was identified by LC/MS and was characterized by ((1)H NMR, (13)C NMR, 2D-NMR ((1)H-(1)H COSY, NOESY, HSQC and HMBC), LC/MS/MS, MS/TOF, elemental analysis and IR. This impurity was prepared by isolation and co-injected into HPLC system to confirm the retention time.

  18. Owariensisone: a new iridolactone from the whole plant of Brillantaisia owariensis P. Beauv.

    PubMed

    Foning Tebou, Perrin Lanversin; Mabou, Florence Déclaire; Ngnokam, David; Harakat, Dominique; Voutquenne-Nazabadioko, Laurence

    2016-07-01

    From the whole plant of Brillantaisia owariensis P. Beauv, a new iridolactone, owariensisone (1) together with six known compounds (nepetin-7-O-glucoside, choline, sucrose, mannitol, xylitol, 1-O-palmitoyl-2-eicosanoyl-3-O-(6-amino-6-deoxy)-β-d-glucopyranosyl-glycerol) were isolated. Structures of these compounds were established by direct interpretation of their spectral data, mainly HR-TOFESIMS, 1-D NMR ((1)H and (13)C) and 2-D NMR ((1)H-(1)H COSY, HSQC, HMBC, NOESY, TOCSY and DOCSY) and by comparison with the literature.

  19. New clerodane diterpenoids from Croton crassifolius.

    PubMed

    Qiu, Maosong; Cao, Di; Gao, Youheng; Li, Shuhua; Zhu, Jinping; Yang, Bao; Zhou, Lian; Zhou, Yuan; Jin, Jing; Zhao, Zhongxiang

    2016-01-01

    Two new clerodane diterpenoids (1-2), one new clerodane diterpenoid alkaloid (3), as well as thirteen known compounds were isolated from Croton crassifolius. The structures of new compounds were established by a combination of spectroscopic methods, including HRMS, (1)H NMR, (13)C NMR, (1)H (1)H COSY, HSQC, HMBC, NOESY and X-ray crystallographic analysis. Compound 3 is firstly reported as the clerodane-type diterpenoid alkaloid in natural products. All of the compounds were evaluated for in vitro cytotoxic activities against CT26.WT cell using the MTT method.

  20. Anti-inflammatory dimeric furanocoumarins from the roots of Angelica dahurica.

    PubMed

    Yang, Wan-Qing; Song, Yue-Lin; Zhu, Zhi-Xiang; Su, Cong; Zhang, Xu; Wang, Juan; Shi, She-Po; Tu, Peng-Fei

    2015-09-01

    Seven new dimeric furanocoumarins, dahuribiethrins A-G (1-7), were isolated from the roots of Angelica dahurica. Their structures were determined by chemical derivatization and extensive spectroscopic techniques, including (1)H NMR, (13)C NMR, HSQC, (1)H-(1)H COSY, HMBC, and NOESY experiments. Compounds 2, 3, 4, and 5 exhibited significant inhibition of nitric oxide production in the lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells with IC50 values in the range of 8.8-9.8 μM.

  1. A new sesquiterpenoid quinone with cytotoxicity from Abelmoschus sagittifolius.

    PubMed

    Chen, De-Li; Zhang, Xiao-Po; Ma, Guo-Xu; Wu, Hai-Feng; Yang, Jun-Shan; Xu, Xu-Dong

    2016-01-01

    A new sesquiterpenoid quinone, Acyl hibiscone B (1), together with five known compounds, (R)-lasiodiplodin (2), (R)-de-O-methyllasiodiplodin, (3) dibutyl phthalate (4), (R)-9-phenylnonan-2-ol (5) and hibiscone B (6), was obtained from the stem tuber of Abelmoschus sagittifolius. The structure of compound 1 was elucidated by analysing its (1)H and (13)C NMR, (1)H-(1)H COSY, HSQC, HMBC, NOESY and HR-ESI-MS values. Compound 1 showed significant cytotoxicity against Hela and HepG-2 human cancer cell lines.

  2. α-Glucosidase inhibitor from Buthus martensi Karsch.

    PubMed

    Kim, Shin-Duk

    2013-01-15

    A bioassay-guided fractionation of an ethanol extract of Buthus martensi Karsch led to the isolation of a potent α-glucosidase inhibitor (compound S). The structure was elucidated as a novel β-carboline glucoalkaloid, harmanyl β-d-glucopyranoside, on the basis of spectral data, including (1)H NMR, (13)C NMR, (1)H-(1)H COSY, NOESY, and HMBC. Compound S showed potent inhibitory activity against α-glucosidase, with an IC(50) value of 24 μM. A Lineweaver-Burk plot indicated that its inhibition of α-glucosidase was uncompetitive, with a Ki value of 16.1 μM.

  3. Tzumin A and B, two new lignan derivatives from the barks of Sassafras tzumu.

    PubMed

    Lu, Haixiao; Wu, Feiyan; Jiang, Meixiao; Liang, Weijiang

    2017-04-01

    Two new lignan compounds, 5'-allyl-2,2'-dihydroxy-[1,1'-biphenyl]-5-carboxylic acid (1) and 4,4'-diallyl-[1,1'-biphenyl]-2,2'-diol (2), together with four known compounds (3-6), were isolated from the barks of Sassafras tzumu. The new compounds were determined by NMR ((1)H and (13)C NMR, HSQC, HMBC, (1)H-(1)H COSY, NOESY/ROESY), and MS analysis. Compounds 1-3 showed potent AChE inhibitory activities, with IC50 values of 2.00, 1.81 and 1.91 μM, respectively.

  4. Triterpenoid saponins from the shells of Argania spinosa seeds.

    PubMed

    Alaoui, Asma; Charrouf, Zoubida; Soufiaoui, Mohamed; Carbone, Virginia; Malorni, Antonio; Pizza, Cosimo; Piacente, Sonia

    2002-07-31

    Two new oleanene saponins were isolated from the MeOH extract of the shell of Argania spinosa. They possess protobassic acid and 16alpha-protobassic acid as aglycons. The disaccharide moiety linked to C-3 of the aglycon is made up of two glucose units; the pentasaccharide moiety linked to C-28 is made up of arabinose, xylose, and three rhamnose units. Their structures were elucidated by 1D and 2D NMR experiments including (1)H-(1)H (DQF-COSY, 1D TOCSY, and 2D HOHAHA) and (1)H-(13)C (HSQC and HMBC) spectroscopy along with mass spectrometry.

  5. Phytochemical study of leaves of Ocotea caudata from Colombia.

    PubMed

    Gil Archila, Elizabeth; Cuca Suárez, Luis Enrique

    2017-07-03

    This first phytochemical study of leaves of Ocotea caudata led to the isolation of ten isoquinoline alkaloids, one of them previously unreported, S-(+)-9-O-demethylnorpreocoteine (1), three known flavonoids, two phenols, two eudesmane type sesquiterpenoids, one proline derivative, one fatty alcohol and a phytosterol. Their structures were elucidated on the basis of extensive 1D and 2D NMR spectroscopic analyses including HSQC, HMBC, (1)H-(1)H COSY, NOESY, as well as HRESIMS data in addition to comparison with reports in the literature.

  6. New Prenylxanthones from the Deep-Sea Derived Fungus Emericella sp. SCSIO 05240

    PubMed Central

    Fredimoses, Mangaladoss; Zhou, Xuefeng; Lin, Xiuping; Tian, Xinpeng; Ai, Wen; Wang, Junfeng; Liao, Shengrong; Liu, Juan; Yang, Bin; Yang, Xianwen; Liu, Yonghong

    2014-01-01

    Four new prenylxanthones, emerixanthones A–D (1–4), together with six known analogues (5–10), were isolated from the culture of the deep-sea sediment derived fungus Emericella sp. SCSIO 05240, which was identified on the basis of morphology and ITS sequence analysis. The newstructures were determined by NMR (1H, 13C NMR, HSQC, HMBC, and 1H-1H COSY), MS, CD, and optical rotation analysis. The absolute configuration of prenylxanthone skeleton was also confirmed by the X-ray crystallographic analysis. Compounds 1 and 3 showed weak antibacterial activities, and 4 displayed mild antifungal activities against agricultural pathogens. PMID:24879543

  7. Triterpene saponins from Cyclamen persicum.

    PubMed

    Mihci-Gaidi, Ghezala; Pertuit, David; Miyamoto, Tomofumi; Mirjolet, Jean-François; Duchamp, Olivier; Mitaine-Offer, Anne-Claire; Lacaille-Dubois, Marie-Aleth

    2010-07-01

    A new triterpene saponin 3-O-beta-D-glucopyranosyl-(1 --> 4)-alpha-L-arabinopyranosyl-16alpha-hydroxy-13beta,28-epoxy-oleanan-30-al (1), along with four known triterpene glycosides (2-5) were isolated from Cyclamen persicum. Their structures were characterized by a combination of 1D- and 2D-NMR (1H-1H COSY, TOCSY, NOESY, HSQC, and HMBC) and MS spectrocopic data. The cytotoxicity of compounds 2 and 4 was evaluated using two human colon cancer cell lines HT-29 and HCT 116.

  8. Flavonoid glycosides and their p-coumaroyl esters from Campylospermum calanthum leaves.

    PubMed

    Elo Manga, Savio S; Tih, Anastasie E; Abderamane, Bintou; Ghogomu, Raphael T; Blond, Alain; Bodo, Bernard

    2012-01-01

    Six new compounds, comprising three flavonoid glycosides and their respective coumaroyl esters, have been isolated and characterized from the methanol extract of the leaves of Campylospermum calanthum, along with three known flavonoid aglycones, 7-O-methyl apigenin (1), 7-O-methyl luteolin (2), and 7-O-methyl quercetin (3). Their structures were elucidated based on chemical evidence as well as spectroscopic analysis including 1D and 2D NMR (1H-1H COSY, HSQC, HMBC, and NOESY) spectroscopy and by comparing their spectral data with those reported for related compounds.

  9. Structure and cross-reactivity of the O-antigen of Providencia stuartii O18 containing 3-acetamido-3,6-dideoxy-D-glucose.

    PubMed

    Kocharova, Nina A; Błaszczyk, Aleksandra; Zatonsky, George V; Torzewska, Agnieszka; Bystrova, Olga V; Shashkov, Alexander S; Knirel, Yuriy A; Rozalski, Antoni

    2004-01-22

    The O-polysaccharide (O-antigen) of Providencia stuartii O18 was obtained by mild acid degradation of the lipopolysaccharide and studied by chemical methods and NMR spectroscopy, including 2D 1H,1H COSY, TOCSY, NOESY and 1H,13C HSQC experiments. The following structure of the tetrasaccharide repeating unit of the polysaccharide was established: [structure: see text] where Qui3NAc is 3-acetamido-3,6-dideoxyglucose. Anti-P. stuartii O18 serum cross-reacted with the O-antigen of Proteus genomospecies 4, which could be accounted for the marked structural similarities of the main chain.

  10. The structure of the O-polysaccharide from the lipopolysaccharide of Providencia stuartii O57 containing an amide of D-galacturonic acid with L-alanine.

    PubMed

    Kocharova, Nina A; Ovchinnikova, Olga G; Bushmarinov, Ivan S; Toukach, Filip V; Torzewska, Agnieszka; Shashkov, Alexander S; Knirel, Yuriy A; Rozalski, Antoni

    2005-03-21

    The O-polysaccharide (O-antigen) was obtained by mild acid degradation of the lipopolysaccharide of Providencia stuartii O57:H29. Studies by sugar and methylation analyses along with (1)H and (13)C NMR spectroscopy, including two-dimensional (1)H,(1)H COSY, TOCSY, ROESY, H-detected (1)H,(13)C HSQC, and HMBC experiments, showed that the polysaccharide contains an amide of D-galacturonic acid with L-alanine and has the following pentasaccharide repeating unit: [formula: see text

  11. Sannastatin, a novel toxic macrolactam polyketide glycoside produced by actinomycete Streptomyces sannanensis.

    PubMed

    Yang, Sheng-Xiang; Gao, Jin-Ming; Zhang, An-Ling; Laatsch, Hartmut

    2011-07-01

    A new rare 20-membered macrocyclic lactam incorporating a diene conjugated olefin, designated sannastatin (1), together with the known structurally related vicenistatin (2), has been isolated from the cultures of Streptomyces sannanensis, a bacteria found in the feces of Ailuropoda melanoleuca. The structure of the new compound was established on the basis of extensive spectroscopic analyses including 1D- and 2D-NMR ((1)H-(1)H COSY, TOCSY, HSQC, HMBC, and NOESY) experiments. Compounds 1 and 2 displayed significant growth inhibitory activity against the brine shrimp (Artemia salina) larvae.

  12. A new coumestan from Tephrosia calophylla.

    PubMed

    Hari Kishore, Pennaka; Vijaya Bhaskar Reddy, Mopuru; Gunasekar, Duvvuru; Marthanda Murthy, Madugula; Caux, Cristelle; Bodo, Bernard

    2003-02-01

    A new coumestan, tephcalostan (1) has been isolated from the whole plant of Tephrosia calophylla BEDD. together with two known flavonoids, 7-O-methylglabranin (2) and kaempferol 3-O-beta-D-glucopyranoside (3). The structure of tephcalostan was elucidated as 5'-(R)-8, 9-methylenedioxy-5'-isopropenyl-4', 5'-dihydrofurano[2', 3':2, 3]coumestan by extensive one-and two-dimensional (1D- and 2D-)-NMR techniques including (1)H-(1)H correlation spectroscopy (COSY), heteronuclear single quantum coherence (HSQC), heteronuclear multiple bond connectivity (HMBC) and nuclear Overhauser enhancement spectroscopy (NOESY) experiments.

  13. Identification of two novel Prodelphinidin A-type dimers from roasted hazelnut skins ( Corylus avellana L.).

    PubMed

    Esatbeyoglu, Tuba; Wray, Victor; Winterhalter, Peter

    2013-12-26

    Two new A-type dimeric prodelphinidins, EGC-(2β→O7, 4β→8)-C and EGC-(2β→O5, 4β→6)-C, were isolated from the skins of roasted hazelnut ( Corylus avellana L.) by low-speed rotary countercurrent chromatography (LSRCCC) and final purification by preparative HPLC. Their structures were determined by a combination of mass spectrometry (HPLC-ESI-MS(n) and HR-ESI-MS) and NMR spectroscopy that included the application of 2D methods ((1)H-(1)H COSY, HSQC, HMBC, and NOESY). Furthermore, circular dichroism (CD) and acid-catalyzed degradation (phloroglucinolysis) confirmed the proposed structures.

  14. New flavonoid C-O-C dimers and other chemical constituents from Garcinia brevipedicellata stem heartwood.

    PubMed

    Abderamane, Bintou; Tih, Anastasie E; Ghogomu, Raphael T; Blond, Alain; Bodo, Bernard

    The methanol extract of the stem heartwood of Garcinia brevipedicellata has furnished three new flavonoid C-O-C dimers, brevipedicilones A (6), B (8) and C (10), along with five previously reported flavonoid dimers, viz. amentoflavone (1), 4″'-O-methylamentoflavone (2), robustaflavone (3), 4'-O-methyl robustaflavone (4) and tetrahinokiflavone (5). The new structures, which are composed of flavanone-flavanonol or flavanonol-flavanonol sub-units, were established based on spectroscopic analysis including 1D and 2D NMR (1H-1H COSY, HSQC, HMBC, and NOESY) spectroscopy, and by comparing their spectral data with those reported for related compounds.

  15. CosI: Coherent Neutrino Scattering with Cesium Iodide

    NASA Astrophysics Data System (ADS)

    Fields, Nicole; Collar, Juan; Hossbach, Todd; Orrell, John; Perumpilly, Gopakumar

    2014-03-01

    Coherent neutrino scattering is a process predicted by the standard model of particle physics that has not yet been observed. For low enough energy neutrinos, O (10 MeV , their scattering cross section is predicted to increase with the square of the number of neutrons in a nucleus. Several difficulties must be overcome in order to observe coherent neutrino scattering, including finding a high-intensity source of these medium-energy neutrinos, a detector with a low enough threshold, and a low enough background. The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory is a convenient source of medium-energy neutrinos and has the added benefit of a neutrino source with known time structure. CsI(Na) is an inorganic scintillator with a relatively high light yield of 39,000 photons/MeV and its emission spectrum is well matched with commonly used biakali photomultiplier tubes (PMTs). Background measurements of a 2 kg CsI(Na) crystal show that these crystals can be grown and encapsulated in a radioclean way.

  16. Epitaxial CoSi2 on MOS devices

    DOEpatents

    Lim, Chong Wee; Shin, Chan Soo; Petrov, Ivan Georgiev; Greene, Joseph E.

    2005-01-25

    An Si.sub.x N.sub.y or SiO.sub.x N.sub.y liner is formed on a MOS device. Cobalt is then deposited and reacts to form an epitaxial CoSi.sub.2 layer underneath the liner. The CoSi.sub.2 layer may be formed through a solid phase epitaxy or reactive deposition epitaxy salicide process. In addition to high quality epitaxial CoSi.sub.2 layers, the liner formed during the invention can protect device portions during etching processes used to form device contacts. The liner can act as an etch stop layer to prevent excessive removal of the shallow trench isolation, and protect against excessive loss of the CoSi.sub.2 layer.

  17. Spectral assignments and structural studies of a warfarin derivative stereoselectively formed by tandem cyclization

    NASA Astrophysics Data System (ADS)

    Velayutham Pillai, M.; Rajeswari, K.; Vidhyasagar, T.

    2015-11-01

    The structural elucidation of a Mannich condensation product of rac-Warfarin with benzaldehyde and methyl amine was carried out using IR, Mass, 1H NMR, 13C NMR, 1H-1H COSY, 1H-13C COSY, DEPT-135, HMBC, NOESY spectra and single crystal X-ray diffraction. Formation of a new pyran ring via a tandem cyclization in the presence of methyl amine was observed. The optimized geometry and HOMO-LUMO energy gap along with other important physical parameters were found by Gaussian 09 program using HF 6-31G (d, p) and B3YLP/DFT 6-31G (d, p) level of theory. The preferred conformation of the piperidine ring in solution state was found to be chair from the NMR spectra. Single crystal X-ray diffraction and optimized geometry (by theoretical study) also confirms the chair conformation in the solid state.

  18. Structure of the O-polysaccharide of Providencia stuartii O4 containing 4-(N-acetyl-L-aspart-4-yl)amino-4,6-dideoxy-D-glucose.

    PubMed

    Kocharova, Nina A; Torzewska, Agnieszka; Zatonsky, George V; Błaszczyk, Aleksandra; Bystrova, Olga V; Shashkov, Alexander S; Knirel, Yuriy A; Rozalski, Antoni

    2004-01-22

    The O-polysaccharide of Providencia stuartii O4 was obtained by mild acid degradation of the lipopolysaccharide, and the following structure of the pentasaccharide repeating unit was established: [structure: see text] where D-Qui4N(L-AspAc) is 4-(N-acetyl-L-aspart-4-yl)amino-4,6-dideoxy-D-glucose, which has not been hitherto found in bacterial polysaccharides. Structural studies were performed using sugar and methylation analyses, Smith degradation and NMR spectroscopy, including conventional 2D 1H,1H COSY, TOCSY, NOESY and 1H,13C HSQC experiments as well as COSY and NOESY experiments run in an H(2)O-D(2)O mixture to reveal correlations for NH protons.

  19. Cytotoxic benzil and coumestan derivatives from Tephrosia calophylla.

    PubMed

    Ganapaty, Seru; Srilakshmi, Guttula Veera Kantha; Pannakal, Steve Thomas; Rahman, Hafizur; Laatsch, Hartmut; Brun, Reto

    2009-01-01

    A benzil, calophione A, 1-(6'-Hydroxy-1',3'-benzodioxol-5'-yl)-2-(6''-hydroxy-2''-isopropenyl-2'',3''-dihydro-benzofuran-5''-yl)-ethane-1,2-dione and three coumestan derivatives, tephcalostan B, C and D were isolated from the roots of Tephrosia calophylla. Their structures were deduced from spectroscopic data, including 2D NMR (1)H-(1)H COSY and (13)C-(1)H COSY experiments. Compounds were evaluated for cytotoxicity against RAW (mouse macrophage cells) and HT-29 (colon cancer cells) cancer cell lines and antiprotozoal activity against various parasitic protozoa. Calophione A exhibited significant cytotoxicity with IC(50) of 5.00 (RAW) and 2.90microM (HT-29), respectively.

  20. [Chemical constituents in the roots of Salvia przewalskii Maxim].

    PubMed

    Chen, Wan-sheng; Jia, Xin-ming; Zhang, Wei-dong; Lou, Zi-yang; Qiao, Chuan-zhuo

    2003-05-01

    To investigate the chemical composition of the root of Salvia przewalskii Maxim. Compounds were isolated by silica gel column chromatography. Structures of these compounds were elucidated by spectral analysis (EI-MS, FAB-MS, 1HNMR, 13CNMR, 1H-1H COSY, 1H-13C COSY, HMBC, NOESY) and phytochemical properties. Eight compounds were isolated and identified as: tanshinone II-A (I), crypotanshinone (II), przewaquinone A (III), sugiol (IV), ursolic acid (V), 2 alpha, 3 alpha-dihydroxy urs-12-ene-28-acid (VI), oleanolic acid (VII), and neo-przewaquinone A (VIII). Compound VIII is a new compound, and compound II, IV, V, VI and VII are isolated from this plant for the first time.

  1. Structure of the O-polysaccharide of Proteus vulgaris O44: a new O-antigen that contains an amide of D-glucuronic acid with L-alanine.

    PubMed

    Toukach, Filip V; Perepelov, Andrei V; Bartodziejska, Beata; Shashkov, Alexander S; Blaszczyk, Aleksandra; Arbatsky, Nikolay P; Rozalski, Antoni; Knirel, Yuriy A

    2003-06-23

    The O-polysaccharide of Proteus vulgaris O44, strain PrK 67/57 was studied by 1H and 13C NMR spectroscopy, including 2D COSY, TOCSY, ROESY, H-detected 1H, 13C HMQC, HMQC-TOCSY and HMBC experiments. The polysaccharide was found to contain an amide of D-glucuronic acid with L-alanine [D-GlcA6(L-Ala)], and the following structure of the linear pentasaccharide repeating unit was established: [structure: see text]. The structural data of the O-polysaccharide and the results of serological studies with P. vulgaris O44 O-antiserum showed that the strain studied is unique among Proteus bacteria, which is in agreement with its classification in a separate Proteus serogroup, O44.

  2. Structure of the O-specific polysaccharide of Proteus penneri 103 containing ribitol and 2-aminoethanol phosphates.

    PubMed

    Drzewiecka, Dominika; Toukach, Philip V; Arbatsky, Nikolay P; Zych, Krystyna; Shashkov, Alexander S; Knirel, Yuriy A; Sidorczyk, Zygmunt

    2002-09-27

    The O-specific polysaccharide of the lipopolysaccharide of Proteus penneri strain 103 was studied using 1H and 13C NMR spectroscopy, including 2D COSY, TOCSY, NOESY, H-detected 1H,(13)C HMQC, 1H, 31P HMQC, and HMBC experiments. It was found that the polysaccharide is built up of oligosaccharide-ribitol phosphate repeating units and thus resembles ribitol teichoic acids of Gram-positive bacteria. The following structure of the polysaccharide was established:where Etn and Rib-ol are ethanolamine and ribitol, respectively. This structure is unique among the known structures of Proteus O-antigens and, therefore, we propose classification of the strain studied into a new Proteus serogroup, O73. The molecular basis for cross-reactivity between O-antiserum against P. penneri 103 and O-antigens of P. mirabilis O33 and D52 is discussed.

  3. Vibrational spectroscopic study, structural analysis, photophysical properties and theoretical calculations of cis-(±)-2,4,5-tris(pyridin-2-yl)imidazoline

    NASA Astrophysics Data System (ADS)

    Baldenebro-López, Jesús; Báez-Castro, Alberto; Glossman-Mitnik, Daniel; Höpfl, Herbert; Cruz-Enríquez, Adriana; Miranda-Soto, Valentín; Parra-Hake, Miguel; Campos-Gaxiola, José J.

    2017-02-01

    cis-(±)-2,4,5-tris(pyridin-2-yl)imidazoline has been fully characterized by FT-IR, FT-Raman, UV-Vis and fluorescence spectroscopy, one- and two-dimensional NMR spectroscopy (1H, 1H-1H gCOSY, 1H-1H gNOESY,13C{1H} ATP, 1H-13C and 1H-15N gHSQC and 1H-13C gHMBC), high-resolution mass spectrometry (HR-FAB+), TG-DSC analysis and low-temperature single-crystal X-ray diffraction analysis. Additionally, the molecular geometry and the vibrational infrared and Raman frequencies were calculated by density functional theory using the M06/6-31G(d) level of theory, showing good agreement with the experimental results. The title compound showed interesting photophysical properties, which were studied experimentally in solution and in the solid state by UV-Vis and fluorescence spectroscopy and compared to the theoretically obtained parameters using TD-DFT calculations. Natural and Mulliken atomic charges and the molecular electrostatic potential (MEP) have been mapped.

  4. Glycosylamines of 4,6-O-butylidene-alpha-D-glucopyranose: synthesis and characterization of glycosylamines, and the crystal structure of 4,6-O-butylidene-N-(o-chlorophenyl)-beta-D-glucopyranosylamine.

    PubMed

    Rajsekhar, Gudneppanavar; Rao, Chebrolu P; Saarenketo, Pauli K; Kolehmainen, Erkki; Rissanen, Kari

    2002-02-11

    A total of nine glycosylamines of 4,6-O-butylidene-alpha-D-glucopyranose were synthesized using primary amines having various groups in their ortho- or para-positions. Among these, six are monoglycosylamines, including one primary glycosylamine, and three are bis-glycosylamines. All these compounds were characterized by 1H, 1H-1H COSY, 1H-13C COSY and 13C NMR spectroscopy and FTIR spectra. The FAB mass spectra provided the molecular weights of the products by exhibiting the corresponding molecular ion peaks. The crystal structure of 4,6-O-butylidene-N-(o-chlorophenyl)-beta-D-glucopyranosylamine revealed the C-1 glycosylation, the beta-anomeric nature, and the 4C1 chair conformation of the saccharide unit in the product. In the lattice two types of dimers exist. While one type of dimer is formed through O-H...O type of interactions, the other type is formed via C-H...O type of interactions. In the direction of these C-H...O type of interactions, the dimeric units are connected to form a chain.

  5. NMR and molecular mechanics study of pyrethrins I and II.

    PubMed

    Rugutt, J K; Henry, C W; Franzblau, S G; Warner, I M

    1999-08-01

    Bioassay-directed fractionation of the organic extract of the Kenyan pyrethrum flowers (Chrysanthemum cinerariaefolium Vissiani) resulted in the isolation of two natural pyrethrin esters, pyrethrin I (PI) and pyrethrin II (PII) as the major constituents. These esters elicited inhibition of the multiple drug resistant (MDR) Mycobacterium tuberculosis. The high-field (1)H and (13)C nuclear magnetic resonance (NMR) chemical shifts of PI and PII were unequivocally assigned using modern two-dimensional (2D) proton-detected heteronuclear multiple-quantum coherence (HMQC) and heteronuclear multiple-bond correlation (HMBC) experiments. The conformations of both esters were deduced from (1)H-(1)H vicinal coupling constants and confirmed by 2D nuclear Overhauser effect spectroscopy (NOESY). Computer molecular modeling (MM) studies revealed that PI and PII molecules adopt a "love-seat" conformation in chloroform (CDCl(3)) solution.

  6. A New Sucrase Enzyme Inhibitor from Azadirachta indica

    PubMed Central

    Abdelhady, Mohamed I. S.; Shaheen, Usama; Bader, Ammar; Youns, Mahmoud A.

    2016-01-01

    Background: Sucrase enzyme inhibitor considered as an oral anti-diabetic therapy that delays the absorption of eaten carbohydrates, reducing the postprandial glucose and insulin peaks to reach normoglycemia. Materials and Methods: Chromatographic fractionation of the hydroalcoholic extract of leaves of Azadirachta indica growing in KSA, followed by in-vitro assay of sucrase enzyme inhibition activity. Results: This investigation led to the isolation of a new remarkable sucrase enzyme inhibitor; 4’-methyl Quercetin-7-O-β-D-glucuronopyranoside (1) alongside with four known compounds; 2,3-hexahydroxydiphenoyl-(α/β)-D-4C1-glucopyranose (2), Avicularin (3), Castalagin (4) and Quercetin-3-O-glucoside (5). The structure of the new compound (1) was elucidated on the basis of its spectral data, including ESI-MS, UV, 1H NMR, 13C NMR, 1H-1H COSY, HSQC, NOESY and HMBC. Conclusion: Under the assay conditions, hydroalcoholic extract of A. indica and compounds 1-5 exhibited significant sucrase enzyme inhibitory activity. SUMMARY Chromatographic fractionation of the hydroalcoholic extract of leaves of Azadirachta indica, led to the Isolation of a new flavonoid glycoside named 4’-methyl Quercetin-7-O-β-D-glucuronopyranoside, alongside to other 4 known polyphenols. The hydroalcoholic extract as well as the isolated compounds exhibited significant sucrase enzyme inhibitory activity. Abbreviations used: ESI-MS; electrospray ionization-mass spectrometry, UV; ultraviolet, NMR; nuclear magnetic resonance, 1H-1H COSY; 1H-1H correlation spectroscopy, NOESY; nuclear overhauser effect spectroscopy, and HSQC; heteronuclear multiple bond correlation. A. indica; Azadirachta indica. PMID:27563214

  7. A new bioactive steroidal saponin from Sansevieria cylindrica.

    PubMed

    Da Silva Antunes, Alexandra; Da Silva, Bernadete Pereira; Parente, José Paz; Valente, Ana Paula

    2003-02-01

    A new steroidal saponin was isolated from the leaves of Sansevieria cylindrica. Its structure was established as (3beta,12beta,15alpha,25S)-26-(beta-D-glucopyranosyloxy)-22-hydroxyfurost-5-en-3-yl 12-O- (6-deoxy-alpha-L-mannopyranosyl)-15-O-(6-deoxy-alpha-L-mannopyranosyl)-beta-D-glucopyranoside. The structural identification was performed using detailed analyses of (1)H and (13)C NMR spectra including 2D NMR spectroscopic techniques (COSY, HETCOR, HMBC and HMQC) and chemical conversions. The steroidal saponin showed no haemolytic effects in the in vitro assays and demonstrated inhibition of the capillary permeability activity.

  8. A new steroidal saponin from Agave shrevei.

    PubMed

    Pereira Da Silva, Bernadete; Valente, Ana Paula; Paz Parente, José

    2006-04-01

    A new steroidal saponin was isolated from the leaves of Agave shrevei. Its structure was established as 3-[O-beta-D-glucopyranosyl-(1-->2)-O-[O-beta-D-glucopyranosyl-(1-->4)-O-[O-beta-D-glucopyranosyl-(1-->6)]-O-beta-D-glucopyranosyl-(1-->4)-beta-D-galactopyranosyl)-oxy]-(3beta,5alpha,25R)-spirostane. The structural identification was performed using detailed analyses of 1H- and 13C-NMR spectra including 2D NMR spectroscopic techniques (COSY, HETCOR, HMBC, and HMQC) and chemical conversions. The haemolytic activity of the steroidal saponin was evaluated using an in vitro assay.

  9. Structure of a new acidic O-antigen of Proteus vulgaris O22 containing O-acetylated 3-acetamido-3,6-dideoxy-D-glucose.

    PubMed

    Toukach, F V; Bartodziejska, B; Senchenkova, S N; Wykrota, M; Shashkov, A S; Rozalski, A; Knirel, Y A

    1999-05-31

    The acidic O-specific polysaccharide of Proteus vulgaris O22 was studied using 1H and 13C NMR spectroscopy, including 2D COSY, TOCSY, NOESY, and H-detected 1H, 13C heteronuclear multiple-quantum coherence (HMQC) experiments, and the following structure for the branched pentasaccharide repeating unit was established: [sequence: see text] where Qui3NAc is 3-acetamido-3,6-dideoxyglucose, O-acetylation of QuiNAc at position 4 is stoichiometric and at position 2 nonstoichiometric. Serological relationships of P. vulgaris O22 with some other Proteus strains were substantiated on the level of the O-antigen structures.

  10. Structure and cross-reactivity of the O-antigen of Proteus vulgaris O8.

    PubMed

    Perepelov, A V; Babicka, D; Shashkov, A S; Arbatsky, N P; Senchenkova, S N; Rozalski, A; Knirel, Y A

    1999-05-31

    A high-molecular-mass O-specific polysaccharide was obtained by mild acid degradation of Proteus vulgaris O8 lipopolysaccharide followed by gel permeation chromatography. Studies of the polysaccharide by sugar and methylation analyses and 1H and 13C NMR spectroscopy, including 2D COSY, TOCSY, NOESY, and H-detected 1H, 13C heteronuclear multiple-quantum coherence (HMQC) experiments, demonstrated the presence of a tetrasaccharide repeating unit having the following structure: [sequence: see text] The role of an epitope associated with the alpha-L-FucpNAc-(1-->3)-D-GlcpNAc disaccharide in serological cross-reactivity of P. vulgaris O8 is discussed.

  11. Isolation and characterization of a heteropolysaccharide from the corm of Amorphophallus campanulatus.

    PubMed

    Das, Debsankar; Mondal, Subhas; Roy, Sadhan K; Maiti, Debabrata; Bhunia, Bibhas; Maiti, Tapas K; Islam, Syed S

    2009-12-14

    A water-soluble polysaccharide isolated from the aqueous extract of the corm of Amorphophallus campanulatus was found to contain D-galactose, D-glucose, 4-O-acyl-D-methyl galacturonate, and l-arabinose in a molar ratio 2:1:1:1. Structural investigation of the polysaccharide was carried out using acid hydrolysis, methylation analysis, periodate oxidation study, and NMR studies ((1)H, (13)C, DQF-COSY, TOCSY, NOESY, ROESY, HMQC, and HMBC). On the basis of the above-mentioned experiments the structure of the repeating unit of the polysaccharide was established as: This molecule showed splenocyte activation.

  12. Cichorins B and C: two new benzo-isochromenes from Cichorium intybus.

    PubMed

    Hussain, Hidayat; Hussain, Javid; Ali, Samina; Al-Harrasi, Ahmed; Saleem, Muhammad; Miana, Ghulam Abbas; Riaz, Muhammad; Anwar, Saeed; Hussain, Sajjad; Ali, Liaqat

    2012-01-01

    Two new benzo-isochromenes, named cichorins B (1) and C (2), were isolated from Cichorium intybus. The structures of the new compounds were elucidated by detailed spectroscopic analysis such as ¹H, ¹³C NMR, COSY, HMQC, HMBC, and HR-EI-MS. Relative configurations of asymmetric centers of cichorins B and C were determined by the analysis of the ¹H NMR coupling constants together with the 2D NOESY and 1D NOE experiments as well as from [α]²⁵(D) value.

  13. Structural identification and cytotoxic activity of a polysaccharide from the fruits of Lagenaria siceraria (Lau).

    PubMed

    Ghosh, Kaushik; Chandra, Krishnendu; Ojha, Arnab K; Sarkar, Siddik; Islam, Syed S

    2009-03-31

    A water-soluble polysaccharide, isolated from fruiting bodies of Lagenaria siceraria, is composed of methyl-alpha-d-galacturonate, 3-O-acetyl methyl-alpha-d-galacturonate, and beta-d-galactose in a ratio of nearly 1:1:1. Compositional analysis, methylation analysis, periodate oxidation, and NMR studies ((1)H, (13)C, 2D-COSY, TOCSY, NOESY, HMQC, and HMBC) revealed the presence of the following repeating unit in the polysaccharide: [carbohydrate structure: see text] This polysaccharide showed cytotoxic activity in vitro against human breast adenocarcinoma cell line (MCF-7).

  14. Phenolic compounds from the stem bark Erythrina Orientalis and detection of antimalaria activity by ELISA

    NASA Astrophysics Data System (ADS)

    Tjahjadarie, Tjitjik Srie; Saputri, Ratih Dewi; Tanjung, Mulyadi

    2016-03-01

    Erythrina orientalis has local name "Dadap". This plant has known producing alkaloids, flavonoids, pterocarpans, stilbenes, and arylbenzofurans which are active compounds.Three prenylated flavonoids, 8-prenyl-daidzein (1), alpinumisoflavone (2) and 4'-O-methyl licoflavanone (3) had been isolated from the stem bark of Erythrina Orientalis. The structures were elucidated on the basis of spectroscopic data,which are IR, UV, MS, and NMR 1D (1H-NMR and 13C-NMR) and 2D (COSY, HMQC, and HMBC).

  15. Forazoline A: Marine-derived polyketide with antifungal in vivo efficacy

    DOE PAGES

    Wyche, Thomas P.; Piotrowski, Jeff S.; Hou, Yanpeng; ...

    2014-09-04

    Forazoline A, a novel antifungal polyketide with in vivo efficacy against Candida albicans, was discovered using LCMS-based metabolomics to investigate marine-invertebrate-associated bacteria. Forazoline A had a highly unusual and unprecedented skeleton. Acquisition of 13C–13C gCOSY and 13C–15N HMQC NMR data provided the direct carbon–carbon and carbon–nitrogen connectivity, respectively. This approach represents the first example of determining direct 13C–15N connectivity for a natural product. In this paper, using yeast chemical genomics, we propose that forazoline A operated through a new mechanism of action with a phenotypic outcome of disrupting membrane integrity.

  16. Chemical analysis and study of immunoenhancing and antioxidant property of a glucan isolated from an alkaline extract of a somatic hybrid mushroom of Pleurotus florida and Calocybe indica variety APK2.

    PubMed

    Maity, Kousik; Kar Mandal, Eshita; Maity, Saikat; Gantait, Sanjoy K; Das, Debsankar; Maiti, Swatilekha; Maiti, Tapas K; Sikdar, Samir R; Islam, Syed S

    2011-11-01

    A water-soluble glucan isolated from an alkaline extract of fruit bodies of a somatic hybrid mushroom PCH9FB of Pleurotus florida and Calocybe indica var. APK2 strains showed antioxidant properties with immune activation of macrophage, splenocyte, and thymocyte. On the basis of acid hydrolysis, methylation, periodate oxidation and NMR studies ((1)H, (13)C, DEPT-135, DQF-COSY, TOCSY, NOESY, ROESY, HMQC, and HMBC) the structure of the repeating unit of the glucan was established as: [structure: see text].

  17. Structural characterization of an immunoenhancing cytotoxic heteroglycan isolated from an edible mushroom Calocybe indica var. APK2.

    PubMed

    Mandal, Eshita Kar; Maity, Kousik; Maity, Saikat; Gantait, Sanjoy K; Maiti, Swatilekha; Maiti, Tapas K; Sikdar, Samir R; Islam, Syed S

    2011-10-18

    A water-soluble polysaccharide of an edible mushroom Calocybe indica var. APK2 showed immunoenhancing (macrophage, splenocyte, thymocyte, and bone marrow activation) and cytotoxic activity toward HeLa cell lines and found to consist of D-glucose, D-galactose, and L-fucose in a molar ratio of nearly 3:1:1. On the basis of acid hydrolysis, methylation analysis, and NMR studies ((1)H, (13)C, DEPT-135, TOCSY, DQF-COSY, NOESY, ROESY, HMQC, and HMBC), the structure of the repeating unit of the fuco-galacto-glucan was established as: [see formula in text].

  18. Structure and immunology of a heteroglycan from somatic hybrid mushroom of Pleurotus florida and Calocybe indica var. APK2.

    PubMed

    Dey, Biswajit; Bhunia, Sanjoy K; Maity, Kankan K; Patra, Sukesh; Mandal, Soumitra; Behera, Birendra; Maiti, Tapas K; Sikdar, Samir R; Islam, Syed S

    2013-01-01

    A water soluble polysaccharide was isolated from the aqueous extract of the fruit bodies of somatic hybrid mushroom PCH3FB, obtained through protoplast fusion between the strains Pleurotus florida and Calocybe indica var. APK2. On the basis of sugar analysis, methylation analysis, periodate oxidation, and NMR studies ((1)H, (13)C, DEPT-135, DQF-COSY, TOCSY, NOESY, ROESY, HMQC and HMBC), the structure of the repeating unit of the polysaccharide was established as: [formula, see text] This molecule showed macrophage, splenocyte and thymocyte activations.

  19. Structural characterization and study of immunoenhancing and antioxidant property of a novel polysaccharide isolated from the aqueous extract of a somatic hybrid mushroom of Pleurotus florida and Calocybe indica variety APK2.

    PubMed

    Maity, Kousik; Kar Mandal, Eshita; Maity, Saikat; Gantait, Sanjoy K; Das, Debsankar; Maiti, Swatilekha; Maiti, Tapas K; Sikdar, Samir R; Islam, Syed S

    2011-03-01

    A water-soluble polysaccharide was isolated from the aqueous extract of the fruit bodies of somatic hybrid PCH9FB, obtained through intergeneric protoplast fusion between the strains Pleurotus florida and Calocybe indica var. On the basis of total acid hydrolysis, the polysaccharide was found to contain galactose, fucose, and glucose in a molar ratio of nearly 2:1:2. Methylation analysis and NMR experiments ((1)H, (13)C, DEPT-135, DQF-COSY, TOCSY, NOESY, ROESY, HMQC, and HMBC) showed that the structure of the repeating unit present in the polysaccharide was This molecule showed macrophage, splenocyte, thymocyte activation as well as antioxidant property.

  20. Cucurbitane-type triterpenoids from the fruit pulp of Momordica charantia.

    PubMed

    Liao, Yun-Wen; Chen, Chiy-Rong; Kuo, Yueh-Hsiung; Hsu, Jue-Liang; Shih, Wen-Ling; Cheng, Hsueh-Ling; Huang, Tzou-Chi; Chang, Chi-I

    2012-12-01

    Three new cucurbitane-type triterpenoids, 5beta,19-epoxy-23(R)-methoxycucurbita-6,24-dien-3beta-ol (1), 5beta,19-epoxy-23(S)-methoxycucurbita-6,24-dien-3beta-ol (2), and 3beta-hydroxy-23(R)-methoxycucurbita-6,24-dien-5beta,19-olide (3), were isolated from the fruit pulp of Momordica charantia. Their structures were established on the basis of extensive NMR (1H, 13C, COSY, HMQC, HMBC, and NOESY) and EI-MS studies. Compound 1 exhibited cytotoxic activity against the SK-Hep 1 cell line.

  1. Bioactive anthraquinone glycosides from Picramnia antidesma spp. fessonia.

    PubMed

    Solis, P N; Ravelo, A G; Gonzalez, A G; Gupta, M P; Phillipson, J D

    1995-01-01

    A bioactivity guided fractionation, using KB cells and brine shrimp assays, of the methanolic extract from the leaves of Picramnia antidesma yielded two known anthraquinones, aloe-emodin and aloe-emodin anthrone, and three new aloe-emodin C-glycosides, named picramnioside A, picramnioside B and picramnioside C. Structures were established by spectroscopic methods (UV, IR, mass spectrometry, 1H and 13C and 2D NMR including COSY 45, HMQC, HMBC and ROESY). CD was used to establish the absolute configuration of the picramniosides.

  2. Total NMR assignments of new [C7-O-C7'']-biflavones from leaves of the limonene-carvone chemotype of Lippia alba (Mill) N. E. Brown.

    PubMed

    Barbosa, Francisco Geraldo; Lima, Mary Anne Sousa; Silveira, Edilberto Rocha

    2005-04-01

    Phytochemical analysis of leaves of the limonene-carvone chemotype of Lippia alba led to the isolation of two biflavonoids with a new structural pattern with an ether linkage: 5,5''-dihydroxy-6,4',6'',3''',4'''-pentamethoxy-[C(7)--O--C(7'')]-biflavone (1) and 4',4,5,5''-tetrahydroxy-6,6'',3'''-trimethoxy-[C(7)--O--C(7'')]-biflavone (2). Structural elucidation of the new compounds was established on the basis of spectral data, through the use of 1D NMR and several 2D shift correlated NMR pulse sequences (COSY, HMQC, HMBC and NOESY).

  3. A new triterpenoid saponin from Gymnema sylvestre.

    PubMed

    Zhang, Man-Qi; Liu, Yue; Xie, Sheng-Xu; Xu, Tun-Hai; Liu, Tong-Hua; Xu, Ya-Juan; Xu, Dong-Ming

    2012-01-01

    Besides four known compounds, a new triterpenoid saponin was isolated from the stems of Gymnema sylvestre. The structure of the new triterpenoid saponin was established as 3β,16β,22α-trihydroxy-olean-12-ene 3-O-β-D-xylopyranosyl-(1 → 6)-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranoside (1) on the basis of 1D and 2D NMR techniques, including COSY, HMBC, HMQC, and NOESY correlations. Four known compounds 2, 3, 4, and 5 were identified on the basis of spectroscopic data.

  4. Two new phthalate derivatives from Nepeta clarkei (Labiatae).

    PubMed

    Hussain, Javid; Rehman, Najeeb Ur; Hussain, Hidayat; Ali, Liaqat; Al-Harrasi, Ahmed

    2012-01-01

    Two new phthalates bis(2-ethylundecyl)phthalate and bis(2-ethyltridecyl)phthalate have been isolated from the chloroform-soluble portion of the whole plant of Nepeta clarkei along with one known compound β-amyrin. The structures of the two new compounds and β-amyrin were assigned on the basis of their ¹H and ¹³C NMR spectra including 2D NMR techniques such as COSY, HMQC, and HMBC experiments and compared with the literature data.

  5. Isosakuranetin-5-O-rutinoside: a new flavanone with antidepressant activity isolated from Salvia elegans Vahl.

    PubMed

    González-Cortazar, Manáses; Maldonado-Abarca, Ana María; Jiménez-Ferrer, Enrique; Marquina, Silvia; Ventura-Zapata, Elsa; Zamilpa, Alejandro; Tortoriello, Jaime; Herrera-Ruiz, Maribel

    2013-10-25

    Ursolic acid (1) and a new flavanone, 5-O-(6-rhamnosylglucoside)-7-hydroxy-4'-methoxyflavanone (2), were isolated from the leaves of Salvia elegans Vahl. These natural products displayed antidepressant activity in mice as determined by means of a forced swimming test (FST) evaluation. Structural elucidation was carried out by chemical derivatization (acetylation) and spectroscopic analyses, such as 1H- and 13C-NMR and two-dimensional (2-D) COSY, heteronuclear multiple quantum coherence (HMQC), and heteronuclear multiple-bond correlation (HMBC) spectroscopy experiments.

  6. Identification of a new analogue of sildenafil added illegally to a functional food marketed for penile erectile dysfunction.

    PubMed

    Shin, M-H; Hong, M-K; Kim, W-S; Lee, Y-J; Jeoung, Y-C

    2003-09-01

    A new analogue of sildenafil was discovered to have been added illegally to a functional food marketed for penile erectile dysfunction. The structure of the analogue was established by various NMR spectroscopic techniques (including DEPT, COSY, TOCSY, HMQC, HMBC). Because of the addition of a methylene group to sildenafil, the main ingredient of Viagra(R), it was given the name homosildenafil, and this has never been reported previously. An analytical method using HPLC was proposed. Homosildenafil was added as a new inspection item and other foods have since been discovered to contain it.

  7. Bioactive metabolites produced by Chaetomium globosum, an endophytic fungus isolated from Ginkgo biloba.

    PubMed

    Qin, Jian-Chun; Zhang, Ya-Mei; Gao, Jin-Ming; Bai, Ming-Sheng; Yang, Sheng-Xiang; Laatsch, Hartmut; Zhang, An-Ling

    2009-03-15

    A novel cytotoxic chlorinated azaphilone derivative named chaetomugilin D (1), together with three known metabolites, chaetomugilin A (2), chaetoglobosins A (3) and C (4), has been isolated by a bioassay-guided fractionation from the EtOAc extract of the cultures of Chaetomium globosum, an endophytic fungus found in the leaves of Ginkgo biloba. Structure of 1 was established by analyses of spectroscopic methods, including 2D-NMR experiments (COSY, NOESY, HMQC, and HMBC). Compounds 1-4 displayed significant growth inhibitory activity against the brine shrimp (Artemia salina) and Mucor miehei.

  8. Structural studies of a heteropolysaccharide (PS-I) isolated from hot water extract of fruits of Psidium guajava (Guava).

    PubMed

    Mandal, Soumitra; Sarkar, Ramsankar; Patra, Pradip; Nandan, Chanchal K; Das, Debsankar; Bhanja, Sunil K; Islam, Syed S

    2009-07-27

    A water-soluble polysaccharide was isolated from hot aqueous extracts of fruits of Psidium guajava. The polysaccharide was found to contain 2-O-methyl-l-arabinose, 2-O-acetyl-D-galactose, and D-methyl galacturonate in a molar ratio of approximately 1:1:1. On the basis of acid hydrolysis, methylation analysis, periodate oxidation, and NMR studies ((1)H, (13)C, TOCSY, DQF-COSY, NOESY, ROESY, HMQC, and HMBC), the structure of the repeating unit of the polysaccharide was established as [carbohydrate structure: see text].

  9. Chemical analysis of a polysaccharide of unripe (green) tomato (Lycopersicon esculentum).

    PubMed

    Chandra, Krishnendu; Ghosh, Kaushik; Ojha, Arnab K; Islam, Syed S

    2009-11-02

    A polysaccharide (PS-I) isolated from the aqueous extract of the unripe (green) tomatoes (Lycopersicon esculentum) consists of D-galactose, D-methyl galacturonate, D-arabinose, L-arabinose, and L-rhamnose. Structural investigation of the polysaccharide was carried out using total acid hydrolysis, methylation analysis, periodate oxidation study, and NMR studies ((1)H, (13)C, DQF-COSY, TOCSY, NOESY, ROESY, HMQC, and HMBC). On the basis of above-mentioned experiments the structure of the repeating unit of the polysaccharide (PS-I) was established as: [structure: see text].

  10. Simultaneously cycled NMR spectroscopy.

    PubMed

    Parish, David M; Szyperski, Thomas

    2008-04-09

    Simultaneously cycled (SC) NMR was introduced and exemplified by implementing a set of 2-D [1H,1H] SC exclusive COSY (E.COSY) NMR experiments, that is, rf pulse flip-angle cycled (SFC), rf pulse phase cycled (SPC), and pulsed field gradient (PFG) strength cycled (SGC) E.COSY. Spatially selective 1H rf pulses were applied as composite pulses such that all steps of the respective cycles were affected simultaneously in different slices of the sample. This increased the data acquisition speed for an n-step cycle n-fold. A high intrinsic sensitivity was achieved by defining the cycles in a manner that the receiver phase remains constant for all steps of the cycle. Then, the signal resulting from applying the cycle corresponded to the sum of the signals from all steps of the cycle. Hence, the detected free induction decay did not have to be separated into the contributions arising from different slices, and read-out PFGs, which not only greatly reduce sensitivity but also negatively impact lineshapes in the direct dimension, were avoided. The current implementation of SFC E.COSY reached approximately 65% of the intrinsic sensitivity of the conventional phase cycled congener, making this experiment highly attractive whenever conventional data acquisition is sampling limited. Highly resolved SC E.COSY yielding accurate 3J-coupling values was recorded for the 416 Da plant alkaloid tomatidine within 80 min, that is, 12 times faster than with conventional phase cycled E.COSY. SC NMR is applicable for a large variety of NMR experiments and thus promises to be a valuable addition to the arsenal of approaches for tackling the NMR sampling problem to avoid sampling limited data acquisition.

  11. Isolation and anti-hepatitis B virus activity of dibenzocyclooctadiene lignans from the fruits of Schisandra chinensis.

    PubMed

    Xue, Yongbo; Li, Xifeng; Du, Xue; Li, Xiaonian; Wang, Weiguang; Yang, Jianhong; Chen, Jijun; Pu, Jianxin; Sun, Handong

    2015-08-01

    Seven lignans with a dibenzocyclooctadiene skeleton, termed schinlignans A-G, and a 6,7-seco-homolignan, schischinone, together with seven known lignans, were isolated from the fruits of Schisandra chinensis (Turcz.) Baill. Their structures were elucidated by extensive spectroscopic methods, including HRESIMS, IR, UV, and 2D NMR (COSY, HMQC, COSY, and HMBC experiments). The stereochemistry at the chiral centers and the biphenyl moiety, were determined using ROESY, as well as via interpretation of their ECD spectra. Schinlignan G and methylgomisin O exhibited potent anti-hepatitis B virus activity against HBV DNA replication with IC50 values of 5.13 and 5.49μgmL(-1), respectively.

  12. Fluorine detected 2D NMR experiments for the practical determination of size and sign of homonuclear F-F and heteronuclear C-F multiple bond J-coupling constants in multiple fluorinated compounds.

    PubMed

    Aspers, Ruud L E G; Ampt, Kirsten A M; Dvortsak, Peter; Jaeger, Martin; Wijmenga, Sybren S

    2013-06-01

    The use of fluorine in molecules obtained from chemical synthesis has become increasingly important within the pharmaceutical and agricultural industry. NMR characterization of these compounds is of great value with respect to their structure elucidation, their screening in metabolomics investigations and binding studies. The favorable NMR properties of the fluorine nucleus make NMR with fluorine detection of great value in this respect. A suite of NMR 2D F-F- and F-C-correlation experiments with fluorine detection was applied to the assignment of resonances, (n)J(CF)- and (n)J(FF)-couplings as well as the determination of their size and sign. The utilization of this experiment suite was exemplarily demonstrated for a highly fluorinated vinyl alkyl ether. Especially F-C HSQC and J-scaled F-C HMBC experiments allowed determining the size of the J-couplings of this compound. The relative sign of its homo- and heteronuclear couplings was achieved by different combinations of 2D NMR experiments, including non-selective and F2-selective F-C XLOC, F2-selective F-C HMQC, and F-F COSY. The F2-one/two-site selective F-C XLOC versions were found highly useful, as they led to simplifications of the common E.COSY patterns and resulted in a higher confidence level of the assignment by using selective excitation. The combination of F2-one/two-site selective F-C XLOC experiments with a F2-one-site selective F-C HMQC experiment provided the signs of all (n)J(CF)- and (n)J(FF)-couplings in the vinyl moiety of the test compound. Other combinations of experiments were found useful as well for special purposes when focusing for example on homonuclear couplings a combination of F-F COSY-10 with a F2-one-site selective F-C HMQC could be used. The E.COSY patterns in the spectra demonstrated were analyzed by use of the spin-selective displacement vectors, and in case of the XLOC also by use of the DQ- and ZQ-displacement vectors. The variety of experiments presented shall contribute to

  13. Enzymatic synthesis and characterization of arbutin glucosides using glucansucrase from Leuconostoc mesenteroides B-1299CB.

    PubMed

    Moon, Young Hwan; Nam, Seung Hee; Kang, Jin; Kim, Young-Min; Lee, Jin-Ha; Kang, Hee-Kyung; Breton, Vincent; Jun, Woo-Jin; Park, Ki-Deok; Kimura, Atsuo; Kim, Doman

    2007-12-01

    Two arbutin glucosides were synthesized via the acceptor reaction of a glucansucrase from Leuconostoc mesenteroides B-1299CB with arbutin and sucrose. The glucosides were purified by Bio-gel P-2 column chromatography and high-performance liquid chromatography, and the structures were elucidated as 4-hydroxyphenyl beta-isomaltoside (arbutin-G1), 4-hydroxyphenyl beta-isomaltotrioside (arbutin-G2), according to the results of (1)H, (13)C, heteronuclear single-quantum coherence, (1)H-(1)H COSY, and heteronuclear multiple-bond correlation analyses. Arbutin glucoside (4-hydroxyphenyl beta-isomaltoside) exhibited slower effects on 1,1-diphenyl-2-picrylhydrazyl radical scavenging and similar effects on tyrosinase inhibition, and increased inhibitory effect on matrix metalloproteinase-1 production induced by UVB than arbutin.

  14. Complex mixture analysis of organic compounds in green coffee bean extract by two-dimensional NMR spectroscopy.

    PubMed

    Wei, Feifei; Furihata, Kazuo; Hu, Fangyu; Miyakawa, Takuya; Tanokura, Masaru

    2010-11-01

    A complex mixture analysis by one- and two-dimensional nuclear magnetic resonance (NMR) spectroscopy was carried out for the first time for the identification and quantification of organic compounds in green coffee bean extract (GCBE). A combination of (1)H-(1)H DQF-COSY, (1)H-(13)C HSQC, and (1)H-(13)C CT-HMBC two-dimensional sequences was used, and 16 compounds were identified. In particular, three isomers of caffeoylquinic acid were identified in the complex mixture without any separation. In addition, GCBE components were quantified by the integration of carbon signals by use of a relaxation reagent and an inverse-gated decoupling method without a nuclear Overhauser effect. This NMR methodology provides detailed information about the kinds and amounts of GCBE components, and in our study, the chemical makeup of GCBE was clarified by the NMR results. 2010 John Wiley & Sons, Ltd.

  15. Chemical constituents on the aerial parts of Artemisia selengensis and their IL-6 inhibitory activity.

    PubMed

    Kim, A Ryun; Ko, Hae Ju; Chowdhury, Md Anisuzzaman; Chang, Young-Su; Woo, Eun-Rhan

    2015-06-01

    Ten compounds, 1',3'-propanediol,2'-amino-1'-(1,3-benzodioxol-5-yl) (1), artanomaloide (2), canin (3), eupatilin (4), quercetin-3-O-β-D-glucoside-7-O-α-L-rhamnoside (5), 1,3-di-O-caffeoylquinic acid (6), isoquercitrin (7), pinoresinol-4-O-β-D-glucoside (8), scopolin (9), and isofraxidin-7-O-β-D-glucopyranoside (10) were isolated from the aerial parts of A. selengensis. The structures of compounds (1-10) were identified based on 1D and 2D NMR, including (1)H-(1)H COSY, HSQC, HMBC and NOESY spectroscopic analyses. Among them, compound 1 was isolated from this plant for the first time as a naturally occurring compound. The inhibitory activity of these isolated compounds against interleukin-6 (IL-6) production in TNF-α stimulated MG-63 cells was also examined.

  16. Novel synthesis, structural analysis, photophysical properties and theoretical study of 2,4,5-tris(2-pyridyl)imidazole

    NASA Astrophysics Data System (ADS)

    Báez-Castro, Alberto; Baldenebro-López, Jesús; Glossman-Mitnik, Daniel; Höpfl, Herbert; Cruz-Enríquez, Adriana; Miranda-Soto, Valentín; Parra-Hake, Miguel; Campos-Gaxiola, José J.

    2015-11-01

    2,4,5-Tris(2-pyridyl)imidazole has been successfully synthetized by a novel synthetic route and fully characterized by FT-IR,UV-Vis and fluorescence spectroscopy, one- and two-dimensional NMR spectroscopy (1H, 13C{1H} ATP, 1H-1H COSY, NOESY 1H-13C HSQC and HMBC) high-resolution, mass spectrometry (HR-FAB+), and single-crystal X-ray diffraction analysis. Additionally, the molecular geometry, vibrational frequencies and infrared intensities were calculated by density functional theory using the M06/6-31G(d) level of theory, showing good agreement with the experimental results. The title compound showed interesting photophysical properties, which were studied experimentally in solution and in the solid state by UV-Vis and fluorescence spectroscopy, and theoretically using TD-DFT calculations. Natural and Mulliken atomic charges and the molecular electrostatic potential (MEP) have been mapped.

  17. Evaluation of antinociceptive and anti-inflammatory activities of a new triterpene saponin from Bauhinia variegata leaves.

    PubMed

    Mohamed, Mona A; Mammoud, Madeha R; Hayen, Heiko

    2009-01-01

    A new triterpene saponin, named as 23-hydroxy-3alpha-[O-alpha-L-1C4-rhamnopyranosyl-(1"-->4')-O-alpha-L-4C1-arabinopyranosyl-oxy]olean-12-en-28-oic acid O-alpha-L-1C4-rhamnopyranosyl-(1"'-->4")-O-beta-D-4C1-glucopyranosyl-(1"-->6"')-O-beta-D-4C1-glucopyranosyl ester (9), was isolated from the leaves of Bauhinia variegata Linn. In addition, six flavonoid compounds along with two cinnamic acid derivatives were isolated and identified based on their chromatographic properties, and chemical and spectral data (ESI-high resolution-MSn, 1H NMR, 13C NMR, 1H-1H COSY, HSQC, and HMBC). Compound 9 was found to be nontoxic (LD50) and to have significant anti-inflammatory and antinociceptive activities. It also showed a slight antischistosomal activity.

  18. A new megastigmane glycoside from Akebia quinata.

    PubMed

    Jin, Hong-Guang; Kim, A Ryun; Ko, Hae Ju; Woo, Eun-Rhan

    2015-01-01

    A new megastigmane glycoside, 8S*,9R*-megastigman-3-one-4,6-diene-8,9-diol-9-O-β-D-glucopyranoside, named akequintoside D (1), as well as six known compounds, roseoside II (2), 3-O-caffeoylquinic acid (3), methyl-3-O-caffeoylquinate (4), 3,4,5-trimethoxyphenyl-β-D-glucopyranoside (5), cuneataside D (6), 3,4-dimethoxyphenyl-6-O-(α-L-rhamnopyranosyl)-β-D-glucopyranoside (7) were isolated from the stem of Akebia quinata. The structures of compounds (1-7) were identified based on 1D and 2D NMR, including (1)H-(1)H COSY, HSQC, HMBC and NOESY spectroscopic analyses. The inhibitory activity of these isolated compounds against interleukin-6 (IL-6) production in TNF-α stimulated MG-63 cells was also examined.

  19. Spectroscopic, crystal structural and electrochemical studies of zinc(II)-Schiff base complex obtained from 2,3-diaminobenzene and 2-hydroxy naphthaldehyde.

    PubMed

    Ouari, Kamel; Bendia, Sabrina; Weiss, Jean; Bailly, Corinne

    2015-01-25

    Mononuclear zinc(II) complex, [Zn(II)L], where L is a dianionic ligand, has been synthesized and characterized by elemental analysis, electronic, IR and NMR [(1)H, (13)C, DEPT, (1)H-(1)H COSY, ROESY, HSQC and HMBC] spectroscopic techniques. Structural analysis of the complex by single crystal X-ray crystallography shows the presence of a distorted square planar coordination geometry (NNOO) of the metal center. The crystal of the title complex C28H18N2O2Zn belongs to the orthorhombic system with space group Pmn21. Electrochemical behavior of the Zn(II)L complex has been investigated by cyclic voltammetry on glassy carbon and platinum electrodes in DMF at 100 mV/s scan rate.

  20. X-ray structure, NMR and stability-in-solution study of 6-(furfurylamino)-9-(tetrahydropyran-2-yl)purine - A new active compound for cosmetology

    NASA Astrophysics Data System (ADS)

    Walla, Jan; Szüčová, Lucie; Císařová, Ivana; Gucký, Tomáš; Zatloukal, Marek; Doležal, Karel; Greplová, Jarmila; Massino, Frank J.; Strnad, Miroslav

    2010-06-01

    The crystal and molecular structure of 6-(furfurylamino)-9-(tetrahydropyran-2-yl)purine ( 1) was determined at 150(2) K. The compound crystallizes in monoclinic P2 1/ c space group with a = 10.5642(2), b = 13.6174(3), c = 10.3742(2) Å, V = 1460.78(5) Å 3, Z = 4, R( F) = for 3344 unique reflections. The purine moiety and furfuryl ring are planar and the tetrahydropyran-2-yl is disordered in the ratio 1:3, probably due to the chiral carbon atom C(17). The individual 1H and 13C NMR signals were assigned by 2D correlation experiments such as 1H- 1H COSY and ge-2D HSQC. Stability-in-solution was determined in methanol/water in acidic pH (3-7).

  1. Synthesis, NMR spectroscopic characterization and structure of a divinyldisilazane-(triphenylphosphine)platinum(0) complex: observation of isotope-induced chemical shifts (1)Δ(12/13)C((195)Pt).

    PubMed

    Wrackmeyer, Bernd; Klimkina, Elena V; Schmalz, Thomas; Milius, Wolfgang

    2013-05-01

    Tetramethyldivinyldisilazane-(triphenylphosphine)platinum(0) was prepared, characterized in solid state by X-ray crystallography and in solution by multinuclear magnetic resonance spectroscopy ((1)H, (13)C, (15)N, (29)Si, (31)P and (195)Pt NMR). Numerous signs of spin-spin coupling constants were determined by two-dimensional heteronuclear shift correlations (HETCOR) and two-dimensional (1)H/(1)H COSY experiments. Isotope-induced chemical shifts (1)Δ(12/13)C((195)Pt) were measured from (195)Pt NMR spectra of the title compound as well as of other Pt(0), Pt(II) and Pt(IV) compounds for comparison. In contrast to other heavy nuclei such as (199)Hg or (207)Pb, the "normal" shifts of the heavy isotopomers to low frequencies are found, covering a range of >500 ppb.

  2. A new ent-clerodane diterpenoid from Crassocephalum bauchiense Huch. (Asteraceae).

    PubMed

    Tchinda, Alembert T; Mouokeu, Simplice R; Ngono, Rosalie A N; Ebelle, Madeleine R E; Mokale, Aristide L K; Nono, Diane K; Frédérich, Michel

    2015-01-01

    A phytochemical investigation of the whole plant of Crassocephalum bauchiense Huch. resulted in the isolation of a new clerodane diterpenoid, ent-2β,18,19-trihydroxycleroda-3,13-dien-16,15-olide (1), together with two known flavonoids 3',5-dihydroxy-4',5',6,7,8-pentamethoxyflavone (2) and 4',5-dihydroxy-3',5',6,7,8-pentamethoxyflavone (3). The compounds were tested against the chloroquine-sensitive 3D7 strain of Plasmodium falciparum. Compound 2 showed weak activity (IC50 = 10.1 g/mL) whilst compounds 1 and 3 were inactive. The structures of the compounds were elucidated by using detailed spectral analyses, especially (1)H and (13)C NMR, (1)H-(1)H COSY, NOESY, HMBC and HR-ESI-MS.

  3. Phenolic compounds with IL-6 inhibitory activity from Aster yomena.

    PubMed

    Kim, A Ryun; Jin, Qinglong; Jin, Hong-Guang; Ko, Hae Ju; Woo, Eun-Rhan

    2014-07-01

    A new biflavonoid, named asteryomenin (1), as well as six known phenolic compounds, esculetin (2), 4-O-β-D-glucopyranoside-3-hydroxy methyl benzoate (3), caffeic acid (4), isoquercitrin (5), isorhamnetin-3-O-glucoside (6), and apigenin (7) were isolated from the aerial parts of Aster yomena. The structures of compounds (1-7) were identified based on 1D and 2D NMR, including (1)H-(1)H COSY, HSQC, HMBC and NOESY spectroscopic analyses. Compounds 2-7 were isolated from this plant for the first time. For these isolates, the inhibitory activity of IL-6 production in the TNF-α stimulated MG-63 cell was examined. Among these isolates, compounds 4 and 7 appeared to have potent inhibitory activity of IL-6 production in the TNF-α stimulated MG-63 cell, while compounds 1-3 and 5-6 showed moderate activity.

  4. [Studies on chemical structures of two iso-acetogenins from Annona reticulata].

    PubMed

    Yu, J G; Liu, D; Xu, L Z; Yang, S L

    1997-12-01

    Two annonaceous acetogenins: squamone (1) and isoannonareticin (2) have been isolated from the seeds of Annona reticulata L. (Annonaceae). 1 and 2 were shown to be mixtures of 2-epimers by the successful separation of their acetates with preparative TLC, giving: 2,4-cis-squamone diacetate (1a-1), 2,4-trans-squamone diacetate (1a-2), 2,4-cis-isoannonareticin diacetate (2a-1) and 2,4-trans-isoannonareticin diacetate (2a-2). The 2,4-cis-squamone (1-1) and 2,4-trans-isoannonareticin (2-1) are new annonaceous acetogenins. Their structures and relative stereochemistry were elucidated on the basis of spectral analysis (1H-1H COSY and NOE).

  5. Triblock Terpolymers by Simultaneous Tandem Block Polymerization (STBP).

    PubMed

    Freudensprung, Ines; Klapper, Markus; Müllen, Klaus

    2016-02-01

    A route of synthesizing triblock terpolymers in a one-pot, "one-step" polymerization approach is presented. The combination of two distinct polymerization techniques through orthogonal catalyst/initiator functionalities attached to a polymeric linker furnishes novel pathways to ABC-terpolymers. Both polymerizations have to be compatible regarding mechanisms, chosen monomers, and solvents. Here, an α,ω-heterobifunctional poly(ethylene glycol) serves as poly-meric catalyst/initiator to obtain triblock terpolymers of poly(norbornene)-b-poly(ethylene glycol)-b-poly(L-lactic acid) PNB-PEG-PLLA via simultaneous ring opening metathesis poly-merization and ring opening polymerization in a fast one-pot polymerization. Structural characterization of the polymers is provided via (1)H-, DOSY-, and (1)H,(1)H-COSY-NMR, while solution and thin film self-assembly are investigated by dynamic light scattering and atomic force microscopy.

  6. Antimycobacterial physalins from Physalis angulata L. (Solanaceae).

    PubMed

    Januário, A H; Filho, E Rodrigues; Pietro, R C L R; Kashima, S; Sato, D N; França, S C

    2002-08-01

    Crude extracts and fractions from aerial parts of Physalis angulata have been bioassayed for antimycobacterial activity. Fraction A1-29-12 containing physalins B, F and D exhibited a minimum inhibitory concentration value (MIC) against Mycobacterium tuberculosis H(37)Rv strain of 32 microg/mL. Purified physalin B and physalin D were also tested showing MIC values against Mycobacterium tuberculosis H(37)Rv strain of > 128 microg/mL and 32 microg/mL respectively, suggesting that physalin D plays a relevant role in the antimycobacterial activity displayed. Structural elucidation of both physalins D and B was based on detailed (13)C and (1)H NMR spectral analysis with the aid of 2D-correlation spectroscopy ((1)H-(1)H, COSY, HSQC and HMBC). The assignment of the (13)C chemical shift for physalin D is reported here for the first time.

  7. New structure for the O-polysaccharide of Providencia alcalifaciens O27 and revised structure for the O-polysaccharide of Providencia stuartii O43.

    PubMed

    Ovchinnikova, Olga G; Bushmarinov, Ivan S; Kocharova, Nina A; Toukach, Filip V; Wykrota, Marianna; Shashkov, Alexander S; Knirel, Yuriy A; Rozalski, Antoni

    2007-06-11

    The O-polysaccharide was obtained by mild acid degradation of the lipopolysaccharide from Providencia alcalifaciens O27 and studied by sugar and methylation analyses along with (1)H and (13)C NMR spectroscopy, including 2D (1)H,(1)H COSY, TOCSY, ROESY, H-detected (1)H,(13)C HSQC, and HMBC experiments. It was found that the polysaccharide is built up of linear partially O-acetylated tetrasaccharide repeating units and has the following structure: [structure: see text] where Qui4NFo stands for 4-formamido-4,6-dideoxyglucose (4-formamido-4-deoxyquinovose). The O-polysaccharide structure of Providencia stuartii O43 established earlier was revised with respect to the configuration of the constituent 4-amino-4,6-dideoxyhexose (from Rha4N to Qui4N).

  8. Design, synthesis, characterization and in vitro and in vivo anti-inflammatory evaluation of novel pyrazole-based chalcones.

    PubMed

    Chavan, Hemant V; Adsul, Laxman K; Kotmale, Amol S; Dhakane, Valmik D; Thakare, Vishnu N; Bandgar, Babasaheb P

    2015-02-01

    Abstract A series of novel pyrazole-based chalcones have been designed, synthesized from 1-methyl-5-(2,4,6-trimethoxyphenyl)-1H-pyrazole (6). The structures of regioisomers 6 and 7 were determined by 2D (1)H-(1)H COSY, (1)H-(13)C HSQC and (1)H-(13)C HMBC experiments. The newly synthesized compounds were tested for their inhibitory activity against COX-1 and COX-2 using an in vitro cyclooxygenase (COX) inhibition assay. Moreover, they were investigated in vivo for their anti-inflammatory activities using carrageenan-induced rat paw edema model for acute inflammation and cotton pellet-induced granuloma model for chronic inflammation. All the synthesized compounds showed potential to demonstrate anti-inflammatory activities, of particular interest compounds 10i, 10e, 10f, and 10h were found to be potent anti-inflammatory agents.

  9. Nardosinanols A-I and lemnafricanol, sesquiterpenes from several soft corals, Lemnalia sp., Paralemnalia clavata, Lemnalia africana, and Rhytisma fulvum fulvum.

    PubMed

    Bishara, Ashgan; Yeffet, Dina; Sisso, Mor; Shmul, Guy; Schleyer, Michael; Benayahu, Yehuda; Rudi, Amira; Kashman, Yoel

    2008-03-01

    Ten new sesquiterpenes, nardosinanols A-I ( 1- 9) and lemnafricanol ( 10), have been isolated from several Kenyan soft corals, i.e., from Lemnalia sp., Paralemnalia clavata, Lemnalia africana, and Rhytisma fulvum fulvum. The structures and relative stereochemistry of these compounds were elucidated by interpretation of MS, COSY ( (1)H- (1)H correlations), HSQC, HMBC, and NOESY NMR spectroscopic experiments and in the case of 5 also by chemical transformation to compounds 11 and 12. Nine compounds ( 1- 9) are based on the nardosinane skeleton ( 1- 6 are nardosinanes and 7- 9 nornardosinanes). Lemnafricanol ( 10) possesses a novel tricyclic skeleton. Compounds 3, 7, and 10 were found to be toxic to brine shrimp with LC 50 values of 4.0, 0.35, and 0.32 microM, respectively.

  10. Design, synthesis, characterization and anti-inflammatory evaluation of novel pyrazole amalgamated flavones.

    PubMed

    Chavan, Hemant V; Bandgar, Babasaheb P; Adsul, Laxman K; Dhakane, Valmik D; Bhale, Pravin S; Thakare, Vishnu N; Masand, Vijay

    2013-03-01

    A series of novel pyrazole amalgamated flavones has been designed and synthesized from 1-methyl-5-(2,4,6-trimethoxy-phenyl)-1H-pyrazole 6. The structures of regioisomers 6 and 7 were resolved by 2D (1)H-(1)H COSY, (1)H-(13)C HSQC and (1)H-(13)C HMBC experiments. The newly synthesized compounds were tested for their in vitro COX inhibition and in vivo carrageenan induced hind paw edema in rats and acetic acid induced vascular permeability in mice. Although the compounds have inhibitory profile against both COX-1 and COX-2, some of the compounds are found to be selective against COX-2, supported by inhibition of paw edema and vascular permeability. Docking studies were also carried out to determine the structural features which sway the anti-inflammatory activity of the tested compounds. The keto and phenolic -OH are major factors that are prominently involved in interaction with COX-2 active site.

  11. Antitumor germacranolides from Anvillea garcinii.

    PubMed

    Abdel Sattar, E; Galal, A M; Mossa, G S

    1996-04-01

    The aerial parts of Anvillea garcinii yielded two new germacranolides, 9 alpha-hydroxy-1 beta, 10 alpha-epoxyparthenolide (4) and parthenolid-9-one (5), in addition to the known 9 alpha-hydroxyparthenolide (1), 9 beta-hydroxyparthenolide (2), and 9 beta-hydroxy-1 beta, 10 alpha-epoxyparthenolide (3). The structures of the new compounds were elucidated from their spectral data (IR, MS, 1H- and 13C-NMR, 1H-1H COSY, and 1H-13C HETCOR) and by chemical derivatization. The hitherto unreported 13C-NMR data and carbon atom assignments of the previously isolated lactones 1, 2, and 3 were given. The in-vitro antitumor and anti-HIV activities were evaluated for the isolated compounds.

  12. Asterosaponins and glycosylated polyhydroxysteroids from the starfish Culcita novaeguineae and their cytotoxic activities.

    PubMed

    Ngoan, Bui Thi; Hanh, Tran Thi Hong; Vien, Le Thi; Diep, Chau Ngoc; Thao, Nguyen Phuong; Thao, Do Thi; Thanh, Nguyen Van; Cuong, Nguyen Xuan; Nam, Nguyen Hoai; Thung, Do Cong; Kiem, Phan Van; Kim, Young Ho; Minh, Chau Van

    2015-01-01

    Using combined chromatographic methods, two asterosaponins (compounds 1 and 2), including a new compound novaeguinoside E (compound 1), and six glycosylated polyhydroxysteroids (compounds 3-8) were isolated from a methanol extract of the starfish Culcita novaeguineae. Their structures were determined on the basis of spectroscopic data ((1)H and (13)C NMR, HSQC, HMBC, (1)H-(1)H COSY, ROESY, and HRESI-MS) and by comparison with the literature values. The new compound 1 represents the third example of asterosaponins containing the 5α-cholesta-9(1l)-en-3β,6α,20,22-tetraol aglycone. Among isolated compounds, 4-7 exhibited moderate to weak cytotoxic activities against five human cancer cell lines such as Hep-G2 (hepatoma), KB (epidermoid carcinoma), LNCaP (prostate cancer), MCF7 (breast cancer), and SK-Mel2 (melanoma).

  13. Diterpenoid alkaloids and flavonoids from Delphinium trichophorum.

    PubMed

    Lin, Chao-Zhan; Zhao, Zhong-Xiang; Xie, Si-Min; Mao, Ju-Hua; Zhu, Chen-Chen; Li, Xiao-Hui; Zeren-dawa, Bairi; Suolang-qimei, Kangsa; Zhu, Dun; Xiong, Tian-Qin; Wu, Ai-Zhi

    2014-01-01

    Five hetisane-type C20-diterpenoid alkaloids, trichodelphinines A-E, one delnudine-type C20-diterpenoid alkaloid, trichodelphinine F and three known flavonoids, quercetin, quercetin 3-O-β-D-glucopyranoside, and quercetin 3-O-β-D-glucopyranoside-7-O-α-L-arabinopyranoside, were isolated from whole plants of Delphinium trichophorum Franch. Their structures were elucidated on the basis of extensive spectroscopic analysis, including HSQC, HMBC, (1)H-(1)H COSY, NOESY and X-ray crystallographic analysis, and from chemical evidence. The cytotoxic activities of the diterpenoid alkaloids were evaluated using the MTT method, and the IC50 values of their cytotoxicity against A549 cancer cells ranged from 12.03 to 52.79 μM. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Thiotagetin A, a new cytotoxic thiophene from Tagetes minuta.

    PubMed

    Ibrahim, Sabrin R M; Mohamed, Gamal A

    2017-03-01

    Phytochemical investigation of the n-hexane fraction of the methanolic extract of Tagetes minuta L. (Asteraceae) aerial parts afforded a new thiophene derivative: thiotagetin A (3), together with β-sitosterol (1) and stigmasterol (2). The structure of the new thiophene was identified by UV, IR, 1D ((1)H and (13)C), 2D ((1)H-(1)H COSY, HSQC and HMBC) NMR and HRESIMS spectral data. Compound 3 displayed cytotoxic activity against KB and MCF7 cancer cell lines with ED50 values of 2.03 and 3.88 μg/mL, respectively, compared to adriamycin (0.26 and 0.07 μg/mL, respectively).

  15. Photochemical route to actinide-transition metal bonds: synthesis, characterization and reactivity of a series of thorium and uranium heterobimetallic complexes

    SciTech Connect

    Ward, Ashleigh; Lukens, Wayne; Lu, Connie; Arnold, John

    2014-04-01

    A series of actinide-transition metal heterobimetallics has been prepared, featuring thorium, uranium and cobalt. Complexes incorporating the binucleating ligand N[-(NHCH2PiPr2)C6H4]3 and Th(IV) (4) or U(IV) (5) with a carbonyl bridged [Co(CO)4]- unit were synthesized from the corresponding actinide chlorides (Th: 2; U: 3) and Na[Co(CO)4]. Irradiation of the isocarbonyls with ultraviolet light resulted in the formation of new species containing actinide-metal bonds in good yields (Th: 6; U: 7); this photolysis method provides a new approach to a relatively rare class of complexes. Characterization by single-crystal X-ray diffraction revealed that elimination of the bridging carbonyl is accompanied by coordination of a phosphine arm from the N4P3 ligand to the cobalt center. Additionally, actinide-cobalt bonds of 3.0771(5) and 3.0319(7) for the thorium and uranium complexes, respectively, were observed. The solution state behavior of the thorium complexes was evaluated using 1H, 1H-1H COSY, 31P and variable-temperature NMR spectroscopy. IR, UV-Vis/NIR, and variable-temperature magnetic susceptibility measurements are also reported.

  16. Determination of Three-Bond1H3‧-31P Couplings in Nucleic Acids and Protein-Nucleic Acid Complexes by QuantitativeJCorrelation Spectroscopy

    NASA Astrophysics Data System (ADS)

    Clore, G. Marius; Murphy, Elizabeth C.; Gronenborn, Angela M.; Bax, Ad

    1998-09-01

    A new sensitive two-dimensional quantitativeJcorrelation experiment is described for measuring3JH3‧-Pcouplings in nucleic acids and protein-nucleic acid complexes. The method is based on measuring the change in intensity of the1H-1H cross peaks in a constant-time1H-1H COSY experiment which occurs in the presence and absence of3JH3‧-Pdephasing during the constant-time evolution period. For protein-nucleic acid complexes where the protein is13C-labeled but the nucleic acid is not,12C-filtering is readily achieved by the application of a series of13C purge pulses during the constant time evolution period without any loss of signal-to-noise of the nucleic acid cross peaks. The method is demonstrated for the Dickerson DNA dodecamer and a 19 kDa complex of the transcription factor SRY with a 14mer DNA duplex. The same approach should be equally applicable to numerous other problems, including the measurement ofJH-Cdcouplings in cadmium-ligated proteins, or3JCHcouplings in other selectively enriched compounds.

  17. Further Study on Chemical Constituents of Parnassia wightiana Wall: Four New Dihydro-β-agarofuran Sesquiterpene Polyesters

    PubMed Central

    Gao, Zhao-Feng; Zhou, Bo-Hang; Zhao, Jie-Yu; Cao, Fang-Jun; Zhou, Le; Geng, Hui-Ling

    2015-01-01

    Four new (1–4), along with six known (5–10) dihydro-β-agarofuran sesquiterpene polyesters were isolated from the whole plants of Parnassia wightiana. The new compounds were structurally elucidated through spectroscopic analysis including UV (Ultraviolet Spectrum), IR (Infrared Spectrum), 1H-NMR (1Hydrogen-Nuclear Magnetic Resonance), 13C-NMR (13Carbon-Nuclear Magnetic Resonance), DEPT (Distortionless Enhancement by Polarization Transfer), 1H-1H COSY (1H-1H Correlation Spectroscopy), HSQC (Heteronuclear Single Quantum Coherence), HMBC (Heteronuclear Multiple Bond Correlation), NOESY (Nuclear Overhauser Enhancement Spectroscopy) and HR-MS (High Resolution Mass Specttrum) and their absolute configurations were proposed by comparison of NOESY spectra and specific optical rotations with those of known compounds and biosynthesis grounds. Compound 2 is the first sesquiterpene alkaloid isolated from this plant. New compounds 1–4 exhibited some cytotoxic activities against NB4, MKN-45 and MCF-7 cells at 20 μM and of which 4 showed the highest activity against NB4 and MKN-45 cells with inhibition rates of 85.6% and 30.5%, respectively. PMID:25915027

  18. Synthesis and spectroscopic characterization of super-stable rhenium(V)porphyrins

    NASA Astrophysics Data System (ADS)

    Bichan, N. G.; Tyulyaeva, E. Yu.; Khodov, I. A.; Lomova, T. N.

    2014-03-01

    The preparation of rhenium(V) porphyrin complexes {μ-oxo-bis[(oxo)(5,10,15,20-tetraphenyl-21H,23H-porphinato)rhenium(V)] [OReTPP]2O (1), (oxo)(phenoxo)(2,3,7,8,12,13,17,18-octaethyl-5-monophenyl-21H,23H-porphinato)rhenium(V) ORe(PhO)MPOEP (2), (cloro)(oxo)(2,3,7,8,12,13,17,18-octaethyl-5,15-diphenyl-21H,23H-porphinato)rhenium(V) ORe(Cl)5,15DPOEP (4), and (oxo)(phenoxo)(2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphinato)rhenium(V) ORe(PhO)OEP (5)} by the interaction of H2ReCl6 with corresponding porphyrin in boiling phenol is described. (Cloro)(oxo)(2,3,7,8,12,13,17,18-octaethyl-5-monophenyl-21H,23H-porphinato)rhenium(V) ORe(Cl)MPOEP (3) and (oxo)(chloro)(2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphinato)rhenium(V) ORe(Cl)OEP (6) have been prepared by the reaction of axial-ligand substitution from (2) and (5), respectively. Compounds (2-4) were newly synthesized. Characterization of the compounds (1-6) reported herein was made mainly by UV-Visible, IR, 1Н NMR, 1H1H 2D COSY, 1H1H 2D DOSY, 1H1H 2D ROESY, 1H1H 2D TOCSY spectroscopic techniques and elemental analysis. The stability of the complexes in solutions when exposed to strong acids at the presence of atmospheric oxygen has been estimated. Compounds (2-4) and (6) show them super-stable since they do not undergo dissociation along MN bonds in concentrated H2SO4 under heating up to 363 K. Compounds (3) and (4) undergo one-electron oxidation to form stable π-cation radicals ORe(HSO)P under these conditions. The products of the reaction between all studied porphyrins and concentrated H2SO4 were isolated in CHCl3 by reprecipitation onto ice and proved to be rhenium(V) complexes ORe(HSO4)P.

  19. Materials Data on Er3CoSi3 (SG:12) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-07-25

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  20. RT/OS — realtime programming and application environment for the COSY control system

    NASA Astrophysics Data System (ADS)

    Weinert, A.; Hacker, U.; Haberbosch, Ch.; Henn, K.; Simon, M.

    1994-12-01

    This paper presents the highlights and constraints of RT/OS and how it can be used at other places. The support of approximately 1000 VME and VXI CPUs in network-based multiprocessor systems needs a special set of programming tools and application environment which are bundled as the RT/OS Real-Time-Operating-System. Supporting the Motorola 680χ0 processors and micro-controller with a development system on UNIX and MS-DOS platforms, the tool set gives the opportunity of bringing small embedded controllers as well as VME multiprocessor systems into operation. The tool set includes a cross compiler and a special version of a remote debugger, as well as application support such as downloading and configuration management. The main feature is a modular kernel with message-based task switching, using the rendezvous principle to allow easy extension. Special features of this kernel for a distributed system are networking with the Berkeley socket library supporting TCP/IP, XNS and Novell Netware, a multiprocessor system on VMEbus with the interprocessor Communication Module (IPC), a device driver library for almost every G64 I/O card using a FieldBus Interface called PDV and a X11R4 port.

  1. Materials Data on CoSi (SG:198) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-02-10

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  2. Origin of step-like behavior in the Co/Si system.

    PubMed

    Sagdeo, Archna; Rai, Sanjay; Srivastava, A K; Lodha, G S; Rawat, Rajeev; Le Guen, K; Jonnard, P

    2011-06-22

    A systematic investigation of the structure, nature of the interface and their possible connections with magnetic properties for the as-deposited Co/Si/Co trilayer system has been carried out. X-ray reflectivity, cross-sectional transmission electron microscopy and x-ray emission measurements performed on the Co/Si/Co trilayer system show that when the Si layer thickness is less than ∼ 20 Å, the full Si layer is converted into a cobalt silicide layer whereas when the Si layer thickness > 20 Å along with the silicide layer. the pure Si layer also remains. A comparison of magneto-optical Kerr effect and magnetoresistance measurements reveals the absence of antiferromagnetic coupling in these samples. Double-step-like magnetization, in the case of Si layer thickness > 20 Å between two Co layers, is explained by magnetization reversal of two ferromagnetic layers having different coercivities, independent of each other.

  3. Structure of the Co/Si(111) √{13}×√{13} surface revisited

    NASA Astrophysics Data System (ADS)

    Olyanich, D. A.; Utas, T. V.; Alekseev, A. A.; Kotlyar, V. G.; Zotov, A. V.; Saranin, A. A.

    2014-07-01

    The Si(111) √{13}×√{13}-R 13.9°-Co surface reconstruction shows up in the scanning tunneling microscopy images as an array of clusters. Two types of clusters coexist appearing as dark and bright in the images. P. Wetzel with co-workers (Surf. Sci. 604 (2010) 513 and Surf. Sci. 607 (2013) 111) have recently proposed a structural model of the dark cluster containing three Co atoms located in substitutional sites of the Si(111) surface with overlying triangle of six Si adatoms. The bright clusters have been suggested to contain three additional Si atoms on top of the six Si atoms terminating the dark cluster. The proposed models assume that the Si(111) √{13}×√{13}-R 13.9°-Co surface contains 3/13-0.23 ML Co. Our thorough experimental evaluations of the surface composition confirm that the bright cluster adopts three additional Si atoms but unambiguously demonstrate that the actual Co coverage at the Si(111) √{13}×√{13}-R 13.9°-Co surface is 1.4 ± 0.2 ML. To reconcile the reported structural models with the newly determined Co coverage, we suggest that the clusters reside not at the bare Si(111) surface (as suggested previously), but on the silicide Si-Co-Si triple layer on Si(111) substrate. Among about forty models with various types of completed and uncompleted silicide interfaces, the two models (with A8- and B8-type interfaces) have been proven to represent the most stable configurations.

  4. Localized 2D COSY sequences: Method and experimental evaluation for a whole metabolite quantification approach

    NASA Astrophysics Data System (ADS)

    Martel, Dimitri; Tse Ve Koon, K.; Le Fur, Yann; Ratiney, Hélène

    2015-11-01

    Two-dimensional spectroscopy offers the possibility to unambiguously distinguish metabolites by spreading out the multiplet structure of J-coupled spin systems into a second dimension. Quantification methods that perform parametric fitting of the 2D MRS signal have recently been proposed for resolved PRESS (JPRESS) but not explicitly for Localized Correlation Spectroscopy (LCOSY). Here, through a whole metabolite quantification approach, correlation spectroscopy quantification performances are studied. The ability to quantify metabolite relaxation constant times is studied for three localized 2D MRS sequences (LCOSY, LCTCOSY and the JPRESS) in vitro on preclinical MR systems. The issues encountered during implementation and quantification strategies are discussed with the help of the Fisher matrix formalism. The described parameterized models enable the computation of the lower bound for error variance - generally known as the Cramér Rao bounds (CRBs), a standard of precision - on the parameters estimated from these 2D MRS signal fittings. LCOSY has a theoretical net signal loss of two per unit of acquisition time compared to JPRESS. A rapid analysis could point that the relative CRBs of LCOSY compared to JPRESS (expressed as a percentage of the concentration values) should be doubled but we show that this is not necessarily true. Finally, the LCOSY quantification procedure has been applied on data acquired in vivo on a mouse brain.

  5. Spin Filtering of Stored (Anti)Protons: from FILTEX to COSY to AD to FAIR

    SciTech Connect

    Nikolaev, Nikolai; Pavlov, Fyodor

    2007-06-13

    We review the theory of spin filtering of stored (anti)protons by multiple passage through the polarized internal target (PIT). Implications for the antiproton polarization buildup in the proposed PAX experiment at FAIR GSI are discussed.

  6. Low Gilbert damping in Co2FeSi and Fe2CoSi films

    NASA Astrophysics Data System (ADS)

    Sterwerf, Christian; Paul, Soumalya; Khodadadi, Behrouz; Meinert, Markus; Schmalhorst, Jan-Michael; Buchmeier, Mathias; Mewes, Claudia K. A.; Mewes, Tim; Reiss, Günter

    2016-08-01

    Thin highly textured Fe1+xCo2-xSi (0 ≤ x ≤ 1) films were prepared on MgO (001) substrates by magnetron co-sputtering. Magneto-optic Kerr effect (MOKE) and ferromagnetic resonance (FMR) measurements were used to investigate the composition dependence of the magnetization, the magnetic anisotropy, the gyromagnetic ratio, and the relaxation of the films. Both MOKE and FMR measurements reveal a pronounced fourfold anisotropy for all films. In addition, we found a strong influence of the stoichiometry on the anisotropy as the cubic anisotropy strongly increases with increasing Fe concentration. The gyromagnetic ratio is only weakly dependent on the composition. We find low Gilbert damping parameters for all films with values down to 0.0012 ±0.00010.0007 for Fe1.75Co1.25Si. The effective damping parameter for Co2FeSi is found to be 0.0018 ±0.00040.0034 . We also find a pronounced anisotropic relaxation, which indicates significant contributions of two-magnon scattering processes that is strongest along the easy axes of the films. This makes thin Fe1+xCo2-xSi films ideal materials for the application in spin transfer-torque magnetic RAM (STT-MRAM) devices.

  7. Texture of CoSi2 Films on Si(111) (110) and (001) Substrates

    SciTech Connect

    K De Keyser; C Detavernier; J Jordan-Sweet; C Lavoie

    2011-12-31

    Synchrotron radiation was used to study the texture of polycrystalline CoSi{sub 2} films that were formed by a solid-state reaction between a 30 nm Co film and Si(111), (110) and (001) substrates. All films were strongly textured, and several texture components were identified. We discuss the simultaneous occurrence of axiotaxy (i.e. alignment of lattice planes across the interface) and several different types of epitaxy in each of the films. Comparison of the different texture components observed on the three substrate orientations suggests a strong preference for the alignment of CoSi{sub 2}{l_brace}110{r_brace} planes in the film with Si{l_brace}110{r_brace} planes in the substrate, and twinning around Si[111] directions.

  8. Materials Data on CoSi (SG:221) by Materials Project

    SciTech Connect

    Kristin Persson

    2016-04-23

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  9. Spin Filtering of Stored (Anti)Protons: from FILTEX to COSY to AD to FAIR

    SciTech Connect

    Nikolaev, Nikolai; Pavlov, Fyodor

    2008-04-30

    We review the theory of spin filtering of stored (anti) protons by multiple passage through a polarized internal target (PIT). The implications for the antiproton polarization buildup in the proposed PAX experiment at FAIR are discussed.

  10. Femtosecond laser heat affected zones profiled in Co/Si multilayer thin films

    SciTech Connect

    Picard, Yoosuf N.; Yalisove, Steven M.

    2008-01-07

    In this letter, we describe an approach for assessing collateral thermal damage resulting from high intensity, femtosecond laser irradiation. Polycrystalline Co thin films deposited on Si (100) substrates and buried under an amorphous Si film were prepared for plan-view transmission electron microscopy (TEM) prior to laser irradiation by femtosecond laser pulses. A heat affected zone (HAZ) resulting from single pulse irradiation at a fluence of 0.9 J/cm{sup 2} was determined by TEM imaging and point-wise selected area diffraction. The spatially Gaussian laser pulse generated a HAZ extending up to 3 {mu}m radially from the femtosecond laser irradiated region.

  11. Materials Data on Nb4CoSi (SG:124) by Materials Project

    SciTech Connect

    Kristin Persson

    2015-02-09

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  12. The Legionella pneumophila replication vacuole: making a cosy niche inside host cells.

    PubMed

    Isberg, Ralph R; O'Connor, Tamara J; Heidtman, Matthew

    2009-01-01

    The pathogenesis of Legionella pneumophila is derived from its growth within lung macrophages after aerosols are inhaled from contaminated water sources. Interest in this bacterium stems from its ability to manipulate host cell vesicular-trafficking pathways and establish a membrane-bound replication vacuole, making it a model for intravacuolar pathogens. Establishment of the replication compartment requires a specialized translocation system that transports a large cadre of protein substrates across the vacuolar membrane. These substrates regulate vesicle traffic and survival pathways in the host cell. This Review focuses on the strategies that L. pneumophila uses to establish intracellular growth and evaluates why this microorganism has accumulated an unprecedented number of translocated substrates that are targeted at host cells.

  13. Spin Filtering of Stored (Anti)Protons: from FILTEX to COSY to AD to FAIR

    NASA Astrophysics Data System (ADS)

    Nikolaev, Nikolai; Pavlov, Fyodor

    2008-04-01

    We review the theory of spin filtering of stored (anti) protons by multiple passage through a polarized internal target (PIT). The implications for the antiproton polarization buildup in the proposed PAX experiment at FAIR are discussed.

  14. Target Section for Spin Filtering Studies at Cosy and Cern/ad

    NASA Astrophysics Data System (ADS)

    Barschel, C.; Rathmann, F.; Sarkadi, J.; Ströher, H.; Ciullo, G.; Lenisa, P.; Statera, M.; Grigoryev, K.; Nass, A.; Steffens, E.; Tagliente, G.

    2011-01-01

    The PAX (Polarized Antiproton eXperiment) collaboration aims to polarize a stored antiproton beam by means of spin filtering. The setup requires a polarized internal gas target (PIT) surrounded by silicon detectors.1 An overview of the target configuration necessary for spin filtering is presented. The setup of the PIT is discussed with an emphasis on the working principle of the Breit-Rabi Polarimeter (BRP) including the calibration procedure. Furthermore, some preliminary results of the BRP signal and transitions tuning are presented.

  15. Spin Filtering of Stored (Anti)Protons: from FILTEX to COSY to AD to FAIR

    NASA Astrophysics Data System (ADS)

    Nikolaev, Nikolai; Pavlov, Fyodor

    2007-06-01

    We review the theory of spin filtering of stored (anti)protons by multiple passage through the polarized internal target (PIT). Implications for the antiproton polarization buildup in the proposed PAX experiment at FAIR GSI are discussed.

  16. Novel syntheses of hexahydro-1H-pyrrolo[1,2-a]ĭmidazoles and Octahydroimidazo[1,2-a]pyridines.

    PubMed

    Katritzky, A R; Qiu, G; He, H Y; Yang, B

    2000-06-16

    1-Phenyl-5-(benzotriazol-1-yl)hexahydro-1H-pyrrolo[1,2-a]ĭmidazole (18) and 1-phenyl-5-benzotriazolyloctahydroimidazo[1,2-a]pyridine (27) were readily prepared from succindialdehyde or glutaraldehyde, benzotriazole, and N-phenylethylenediamine. Synthons 18 and 27 reacted with Grignard reagents, allylsilanes, silyl ethers, and triethyl phosphite to produce 1-phenyl-5-substituted-hexahydro-1H-pyrrolo[1,2-a]ĭmidazoles 20a-f, 22, 24a,b, and 25 and 1-phenyl-5-substituted-octahydroimidazo[1, 2-a]pyridines 28a-e, 32, 33a,b, and 34 in good to excellent yields. The configurations of 20, 22, 24, and 25 were determined to be cis isomers by NOE experiment, while the configurations and conformations of 28a-e, 32, 33a,b, and 34 were elucidated by (1)H-(1)H COSY and (1)H-(13)C COSY.

  17. Synthesis, spectral and structural characterization of isobutyl 4-(2-chlorophenyl)-5-cyano-6-(((dimethylamino)methylene)amino)-2-methyl-4H-pyran-3-carboxylate

    NASA Astrophysics Data System (ADS)

    Udhaya Kumar, C.; Velayutham Pillai, M.; Gokula Krishnan, K.; Ramalingan, C.

    2017-09-01

    A fascinating selectivity in the direction of the formation of the formamidine was observed upon the reaction of isobutyl 6-amino-4-(2-chlorophenyl)-5-cyano-2-methyl-4H-pyran-3-carboxylate with N,N-dimethyl formamide. A development in selectivity is explored and a probable mechanism for the reaction is also proposed. The formamidine has been analyzed by FT-IR, FT-Raman, LC-MS and NMR (1D and 2D (1H-1H COSY, 1H-13C COSY and HMBC)) spectra. The experimental findings are compared with the theoretical data calculated by using DFT-B3LYP with 6-311++G(d,p) basis set. A good agreement has been observed between experimental and theoretical data. Single crystal X-ray structural analysis of isobutyl 4-(2-chlorophenyl)-5-cyano-6-(((dimethylamino)methylene)amino)-2-methyl-4H-pyran-3-carboxylate (PDMF), evidences the conformation of pyran ring as ;flattened-boat;.

  18. Structure of the O-polysaccharide and serological cross-reactivity of the Providencia stuartii O33 lipopolysaccharide containing 4-(N-acetyl-D-aspart-4-yl)amino-4,6-dideoxy-D-glucose.

    PubMed

    Torzewska, Agnieszka; Kocharova, Nina A; Zatonsky, George V; Blaszczyk, Aleksandra; Bystrova, Olga V; Shashkov, Alexander S; Knirel, Yuriy A; Rozalski, Antoni

    2004-06-01

    The O-polysaccharide of Providencia stuartii O33 was obtained by mild acid degradation of the lipopolysaccharide and the following structure of the tetrasaccharide repeating unit was established: -->6)-alpha-D-GlcpNAc-(1-->4)-alpha-D-GalpA-(1-->3)-alpha-D-GlcpNAc-(1-->3)-beta-D-Quip4N(Ac-D-Asp)-(1-->, where d-Qui4N(Ac-D-Asp) is 4-(N-acetyl-D-aspart-4-yl)amino-4,6-dideoxy-D-glucose. Structural studies were performed using sugar and methylation analyses and NMR spectroscopy, including conventional 2D 1H, 1H COSY, TOCSY, NOESY and 1H, 13C HSQC experiments as well as COSY and NOESY experiments in an H2O-D2O mixture to reveal correlations for NH protons. The O-polysaccharide of P. stuartii O33 shares an alpha-D-GlcpNAc-(1-->3)-beta-D-Quip4N(Ac-D-Asp) epitope with that of Proteus mirabilis O38, which seems to be responsible for a marked serological cross-reactivity of anti-P. stuartii O33 serum with the lipopolysaccharide of the latter bacterium. P. stuartii O33 is serologically related also to P. stuartii O4, whose O-polysaccharide contains a lateral beta-D-Qui4N(Ac-L-Asp) residue.

  19. Investigation of olefinic structures in class I resinites by isolation and characterization of soluble polylabdanoids

    SciTech Connect

    Clifford, D.J.; Botto, R.E.; Anderson, K.B.

    1996-10-01

    Resinites derived from labdatriene structures (Class I) are ubiquitous throughout the geosphere. A soluble polylabdanoid material has been isolated by sequential extraction with organic solvents. Solid- and liquid-state NMR spectroscopy, and Py-GC-MS, indicate that at least for immature resinites, the extractable polymer is representative of the insoluble, polylabdanoid material, which constitutes the bulk of most Class I resinites. With increasing maturity, the dominant chemical transformation that occurs in these materials is the {open_quotes}loss{close_quotes} of exomethylene structures and depletion of olefinic character from {approximately}two to {approximately}one olefin per monomer unit. To investigate the fate of olefinic structures and to determine the nature of the residual olefin distribution in these materials, two-dimensional NMR correlation spectroscopies (COSY and HMQC) and nuclear Overhauser experiments (NOESY) have been undertaken. Results from these analyses and their implications to the maturation of Class-I resinites will be discussed.

  20. (6R,9S)-6′-(4″-Hydroxybenzoil)-Roseoside, a new megastigmane derivative, isolated from Ouratea polyantha Engl. (Ocnhaceae) and its effect over hepatic glucose-6-phosphatase

    PubMed Central

    Bermúdez, Jairo; Rodríguez, María; Hasegawa, Masahisa; González-Mujica, Freddy; Duque, Sandra; Ito, Yoichiro

    2012-01-01

    A new megastigmane derivative, (6R,9S)-6′-(4″-hydroxybenzoil)-roseoside 1 and two known compounds, the biflavone agathisflavone 2 and the carboxylic acid derivative 4-hydroxibenzoic acid 3 were isolated and purified from leaves and stems of Ouratea polyantha Engl. Agathisflavone was isolated in a single high-speed counter-current chromatography run, meanwhile the megastigmane and the carboxylic acid derivatives were purified in two steps, a combination of high-speed countercurrent chromatography and analytical column chromatography. All structures were elucidated on the basis of spectral evidences and comparisons with literatures. Compound 1 was characterized by [α]D20, UV-Vis, IR, MS, 1H-NMR, 13C-NMR, HMQC, HMBC, COSY and NOESY. Compounds 1 and 2 were tested as hepatic glucose-6-phosphatase inhibitors. PMID:22978207

  1. New cytotoxic 1-azaanthraquinones and 3-aminonaphthoquinone from the stem bark of Goniothalamus marcanii.

    PubMed

    Soonthornchareonnon, N; Suwanborirux, K; Bavovada, R; Patarapanich, C; Cassady, J M

    1999-10-01

    Guided by brine shrimp toxicity and human tumor cell toxicity, fractionation of the alcoholic extract from the stem bark of Goniothalamus marcanii led to the isolation of four new 1-azaanthraquinones: marcanines B (3), C (4), D (5), and E (6), along with two known derivatives: marcanine A and dielsiquinone. A new 5-hydroxy-3-amino-2-aceto-1,4-naphthoquinone (7), a possible 1-azaanthraquinone biosynthetic precursor, was also isolated. The structures of the compounds were elucidated by spectroscopic analyses, mainly 1D and 2D NMR techniques ((1)H, (13)C, NOEDS, COSY, HMQC, and HMBC), as well as comparison with literature data. All the compounds except 6 were evaluated for cytotoxic activity. They exhibited significant cytotoxicity against several human tumor cell lines, A-549, HT-29, MCF7, RPMI, and U251 with the ED(50) in the range of 0.04-3.03 microM.

  2. Quinic acid derivatives from Pimpinella brachycarpa exert anti-neuroinflammatory activity in lipopolysaccharide-induced microglia.

    PubMed

    Lee, Seung Young; Moon, Eunjung; Kim, Sun Yeou; Lee, Kang Ro

    2013-04-01

    Five new quinic acid derivatives (1-5), together with 10 known quinic acid derivatives (6-15), were isolated from the MeOH extract of Pimpinella brachycarpa (Umbelliferae). Their structures were established on the basis of spectroscopic analyses including extensive 2D NMR studies (COSY, HMQC and HMBC). Isolated compounds 1-15 were evaluated for their inhibitory activities on nitric oxide (NO) production in an activated murine microglial cell line. Compounds 2, 3, 8 and 11 significantly inhibited NO production without high cell toxicity in lipopolysaccharide (LPS)-activated BV-2 cells, a microglia cell line (IC50=4.66, 12.52, 9.04 and 12.11 μM, respectively). Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Antimicrobial compounds from Pimpinella species growing in Turkey.

    PubMed

    Tabanca, Nurhayat; Bedir, Erdal; Kirimer, Nese; Baser, K Husnu Can; Khan, Shabana I; Jacob, Melissa R; Khan, Ikhlas A

    2003-10-01

    A new, 4-(2-propenyl)-phenyl angelate ( 1) and four known phenylpropanoids ( 2 - 5), were isolated from Pimpinella isaurica, a species endemic in Turkey. One new sesquiterpene, 1-methyl-4-(5-methyl-1-methylenehex-4-enyl)-7-oxabicyclo[4.1.0]heptane ( 6) was obtained from P. aurea and two known phenylpropanoids were isolated ( 7, 8), from P. corymbosa. The structure elucidation of the new compounds 1 and 6 was achieved by a combination of one- ( (1)H, and (13)C) and two-dimensional NMR techniques (G-DQF-COSY, G-HMQC, and G-HMBC) and LC-ESI-FTMS. Compounds 1, 2, 4, 6, 7, 8 have been evaluated for their antimalarial and antimicrobial activities. Compound 1, 2, 4, 6, 8 had antimicrobial activity against Mycobacterium intracellulare with IC (50) values of 7.0, 15.0, 2.5, 10.0 and 1.5 microg/mL, respectively.

  4. In vitro and in vivo study of cucurbitacins-type triterpene glucoside from Citrullus colocynthis growing in Saudi Arabia against hepatocellular carcinoma.

    PubMed

    Ayyad, Seif-Eldin N; Abdel-Lateff, Ahmed; Alarif, Walied M; Patacchioli, Francesca R; Badria, Farid A; Ezmirly, Saleh T

    2012-03-01

    Chromatographic investigation of fruits obtained from Citrullus colocynthis, growing in Saudi Arabia, led to isolation of two compounds; Cucurbitacin E glucoside (Cu E, 1), and Cucurbitacin I glucoside (Cu I, 2). The chemical structures of 1 and 2, were elucidated by spectroscopic analyses include; 1D ((1)H and (13)C) and 2D (COSY, HMQC and HMBC) NMR and ESI-MS spectroscopy. The in vitro cytotoxic activity against hepatoma cell line (HepG2) and mice-bearing tumor of Ehrlich's ascites carcinoma (EAC) of the compounds were estimated. Both compounds had potent inhibitory activity on HepG2 with IC(50) 3.5 and 2.8 nmol/mL, respectively. In addition to these activities, the in vivo study employing EAC, showed the capability of both compounds to prolong the survival time, life span and normalize the biochemical parameters of the infected mice with EAC. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Structure of the O-specific polysaccharide of the bacterium Proteus vulgaris O23.

    PubMed

    Perepelov, A V; Shashkov, A S; Babichka, D; Senchenkova, S N; Bartodziejska, B; Rozalski, A; Knirel, Y A

    2000-09-01

    An acidic O-specific polysaccharide was obtained by mild acid degradation of the lipopolysaccharide of the bacterium Proteus vulgaris O23 (strain PrK 44/57) and found to contain 2-acetamido-2-deoxy-D-galactose, 2-acetamido-2-deoxy-D-glucose, and D-galacturonic acid. Based on 1H- and 13C-NMR spectroscopic studies, including two-dimensional correlation spectroscopy (COSY), total correlation spectroscopy (TOCSY), nuclear Overhauser effect spectroscopy (NOESY), and 1H,13C heteronuclear multiple-quantum coherence (HMQC) experiments, the following structure of the branched tetrasaccharide repeating unit of the polysaccharide was established: [figure], where the degree of O-acetylation of the terminal GalA residue at position 4 is about 80%. A structural similarity of the O-specific polysaccharides of P. vulgaris O23 and P. mirabilis O23 is discussed.

  6. Two novel clerodane diterpenenes with NGF-potentiating activities from the twigs of Croton yanhuii.

    PubMed

    Sun, Yihang; Wang, Meicheng; Ren, Quanhui; Li, Shen; Xu, Jing; Ohizumi, Yasushi; Xie, Chunfeng; Jin, Da-Qing; Guo, Yuanqiang

    2014-06-01

    Nerve growth factor (NGF) and analog reagents to promote the neurite outgrowth of nerve cells against the neuron degeneration are expected to be potentially useful for the medical treatment of Alzheimer's disease. In our focus on the discovery of bioactive diterpenes, we investigated the chemical constituents of the plant Croton yanhuii. This investigation led to the isolation and identification of two novel clerodane diterpenes (1 and 2). Their structures were elucidated on the basis of extensive 1D and 2D NMR (COSY, HMQC, HMBC, and NOESY) and mass (ESIMS and HR-ESIMS) spectroscopic data analyses. Further biological screenings showed that both of the compounds enhanced NGF-mediated neurite outgrowth from PC12 cells.

  7. A new phthalide derivative from Peperomia nivalis.

    PubMed

    Vásquez-Ocmín, Pedro; Haddad, Mohamed; Gadea, Alice; Jullian, Valérie; Castillo, Denis; Paloque, Lucie; Cerapio, Juan Pablo; Bourdy, Geneviève; Sauvain, Michel

    2017-01-01

    One new phthalide (1) was isolated from aerial parts of Peperomia nivalis, along with known compounds (2 and 3), reported in this species for the first time. The structure of the new compound was characterised on the basis of 1D ((1)H and (13)C NMR), 2D (COSY, HMQC, HMBC and NOESY) NMR and high-resolution mass spectral (HRMS) data. Compound 2 was isolated from a natural source for the first time but previously synthesised. Compounds 1-3 were evaluated for their anti-Helicobacter pylori and anti-Plasmodium falciparum activities. Compound 1 showed moderate activities against H. pylori (MIC 47.5 μM) and the F32-Tanzania strain of P. falciparum (IC50 8.5 μM). Compounds 2 and 3 exhibited weak anti-H. pylori activity (MIC 241.3 and 237.6 μM, respectively) and were inactive against P. falciparum.

  8. Flavonoid glycosides from Prunus armeniaca and the antibacterial activity of a crude extract.

    PubMed

    Rashid, Fahima; Ahmed, Rehana; Mahmood, Azhar; Ahmad, Zaheer; Bibi, Nazia; Kazmi, Shahana Urooj

    2007-08-01

    Investigations on the chemical constituents of the fruits of Prunus armeniaca have led to the isolation of two new flavonoid glycosides, 4',5,7-trihydroxy flavone-7-O-[beta-D-mannopyranosyl (1'''-->2")]-beta-D-allopyranoside (1) and 3,4',5,7-tetrahydroxy-3',5'-di-methoxy flavone 3-O-[alpha-L-rhamnopyranosyl (1'''-->6")]-beta-D-galactopyranoside (2), from the butanolic fraction of the fruits. The butanolic extract exhibited antibacterial activity against both Gram positive and Gram negative bacteria. The structures of these compounds were elucidated through spectral studies, including 2D-NMR (COSY, NOESY, J-resolved), HMQC and HMBC experiments.

  9. Phenolics and Polyphenolics from Melastomataceae Species.

    PubMed

    Serna, Diana Marcela Ocampo; Martínez, José Hipólito Isaza

    2015-09-25

    The Melastomataceae family, the seventh largest flowering plants, has been studied in several fronts of natural product chemistry, including terpenoids, simple phenolics, flavonoids, quinones, lignans and their glycosides, as well as a vast range of tannins or polyphenols. This review concerns the phenolic and polyphenolic metabolites described in the literature for several genera of this family, the mode of isolation and purification, and the structure elucidation of these new natural products that has been achieved by extensive spectral analyses, including ESI-MS, ¹H-, (13)C-NMR spectra and two-dimensional experiments, COSY, TOCSY, J-resolved, NOESY, HMQC, DEPT, and HMBC, as well as chemical and enzymatic degradations and the chemotaxonomic meaning. Finally, a general biogenetic pathway map for ellagitannins is proposed on the bases of the most plausible free radical C-O oxidative coupling.

  10. Diacarperoxides, norterpene cyclic peroxides from the sponge Diacarnus megaspinorhabdosa.

    PubMed

    Ibrahim, Sabrin R M; Ebel, Rainer; Wray, Victor; Müller, Werner E G; Edrada-Ebel, RuAngelie; Proksch, Peter

    2008-08-01

    Chemical investigation of the hexane extract of the sponge Diacarnus megaspinorhabdosa provided a series of new norterpene derivatives including three norditerpene cyclic peroxides, diacarperoxides A, B, and C (1 to 3), four norsesterterpene cyclic peroxides, diacarperoxides D to G (4 to 7), and the acyclic norsesterterpene diacardiol A (8). In addition, known norterpene peroxide congeners were also isolated, which included a known norsesterterpene cyclic peroxide (9), nuapapuin A methyl ester (10), epimuqubilin B (11), methyl-2-epinuapapuinoate (12), and methyl diacarnoate A (13). The structures of the new compounds were established on the basis of one- and two-dimensional NMR spectroscopic studies ((1)H, (13)C, COSY, HMQC, HMBC, and ROESY) as well as by mass spectrometric analyses. The relative configuration of chiral centers at C-2, C-3, and C-6 was assigned by established empirical rules. All compounds were evaluated for their cytotoxic properties in vitro using several human as well as murine cancer cell lines.

  11. Peltomexicanin, a Peltogynoid Quinone Methide from Peltogyne Mexicana Martínez Purple Heartwood.

    PubMed

    Gutiérrez-Macías, Paulina; Peralta-Cruz, Javier; Borja-de-la-Rosa, Amparo; Barragán-Huerta, Blanca E

    2016-02-04

    Peltomexicanin (7,10-dihydroxy-6,12-dioxa-5H-tetraphen-3-one) is a new peltogynoid quinone methide isolated from Palo Morado (Peltogyne mexicana Martínez) heartwood by column chromatography. Its chemical structure was elucidated by IR, NMR (¹H, (13)C), 2D NMR experiments (COSY, NOESY, HMQC, and HSQC), ESI-MS, and UV-Vis spectroscopic analysis. According to HPLC quantification, this compound is the main pigment and accounts for 1.21% of Palo Morado heartwood material. The antioxidant activity of peltomexicanin and dried methanolic extract (DEx) of purple heartwood was evaluated using the radical of 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assay, and the corresponding values expressed as Trolox equivalents (µmol TE/mg sample) were 4.25 and 4.57, respectively.

  12. Antibacterial Colorants: Characterization of Prodiginines and Their Applications on Textile Materials

    PubMed Central

    Alihosseini, Farzaneh; Ju, Kou-San; Lango, Jozsef; Hammock, Bruce D.; Sun, Gang

    2010-01-01

    A strain of Vibrio sp. isolated from marine sediments produced large quantities of bright red pigments that could be used to dye many fibers including wool, nylon, acrylics, and silk. Characterization of the pigments by electrospray ionization mass spectrometry (ESI-MS) and nuclear magnetic resonance (NMR) revealed three prodiginine-like structures with nonpolar characteristics and low molecular mass. UV–visible spectra of the major constituent in methanol solution showed absorbance at λmax 530 nm wavelength. The accurate mass result showed that the main isolated product has a molecular mass of m/z 323.1997. Further analysis using mass fragmentation (MS/MS), 1H NMR, COSY, HMQC NMR and DEPT confirmed the detailed structure of the pigment with an elementary composition of C20H25N3O. Fabrics dyed with the microbial prodiginines demonstrated antibacterial activity. PMID:18484779

  13. Forazoline A: Marine-derived polyketide with antifungal in vivo efficacy

    SciTech Connect

    Wyche, Thomas P.; Piotrowski, Jeff S.; Hou, Yanpeng; Braun, Doug; Deshpande, Raamesh; McIlwain, Sean; Ong, Irene M.; Myers, Chad L.; Guzei, Ilia A.; Westler, William M.; Andes, David R.; Bugni, Tim S.

    2014-09-04

    Forazoline A, a novel antifungal polyketide with in vivo efficacy against Candida albicans, was discovered using LCMS-based metabolomics to investigate marine-invertebrate-associated bacteria. Forazoline A had a highly unusual and unprecedented skeleton. Acquisition of 13C–13C gCOSY and 13C–15N HMQC NMR data provided the direct carbon–carbon and carbon–nitrogen connectivity, respectively. This approach represents the first example of determining direct 13C–15N connectivity for a natural product. In this paper, using yeast chemical genomics, we propose that forazoline A operated through a new mechanism of action with a phenotypic outcome of disrupting membrane integrity.

  14. Chemical analysis of new water-soluble (1→6)-, (1→4)-α, β-glucan and water-insoluble (1→3)-, (1→4)-β-glucan (Calocyban) from alkaline extract of an edible mushroom, Calocybe indica (Dudh Chattu).

    PubMed

    Mandal, Soumitra; Maity, Kankan K; Bhunia, Sanjoy K; Dey, Biswajit; Patra, Sukesh; Sikdar, Samir R; Islam, Syed S

    2010-12-10

    Two different glucans (PS-I, water-soluble; and PS-II, water-insoluble) were isolated from the alkaline extract of fruit bodies of an edible mushroom Calocybe indica. On the basis of acid hydrolysis, methylation analysis, periodate oxidation, and NMR analysis ((1)H, (13)C, DEPT-135, TOCSY, DQF-COSY, NOESY, ROESY, HMQC, and HMBC), the structure of the repeating unit of these polysaccharides were established as: PS-I: →6)-β-D-Glcp-(1→6)-β-D-glcp-(1→6)-)-β-D-Glcp-(1→ α-D=Glcp (Water-soluble glucan). PS-II: →3)-β-D-Glcp-(1→3)-β-D-glcp-(1→3)-)-β-D-Glcp-(1→3)-β-D-Glcp-(1→ β-D-Glcp (Water-insoluble glucan, Calocyban).

  15. Analgesic, anti-inflammatory, and CNS depressant activities of new constituents of Nepeta clarkei.

    PubMed

    Hussain, Javid; Ur Rehman, Najeeb; Hussain, Hidayat; Al-Harrasi, Ahmed; Ali, Liaqat; Rizvi, Tania Shamim; Ahmad, Mansoor; Mehjabeen

    2012-04-01

    Two new pentacyclic triterpenes named kirmanoic acid (1) and kurramanoic acid (2) have been isolated from the chloroform-soluble portion of the whole plant of Nepeta clarkei Hook. The structures of the two new compounds were assigned on the basis of their ¹H and ¹³C NMR spectra including two-dimensional NMR techniques such as COSY, HMQC, and HMBC experiments. Kirmanoic acid (1) was investigated for analgesic, anti-inflammatory, and CNS depressant activities. Interestingly kirmanoic acid (1) showed strong analgesic activity than standard drug in acetic induced writhing and formalin tests. Similarly kirmanoic acid (1) also showed strong anti-inflammatory activity than its standard drug. The gross behavioral study of kirmanoic acid (1) revealed that it exhibited mild CNS stimulant and muscle relaxant in the mice. Compound 1 showed a slight increase in Locomotor activity and possesses the antidepressant effect. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Isolation, NMR Spectral Analysis and Hydrolysis Studies of a Hepta Pyranosyl Diterpene Glycoside from Stevia rebaudiana Bertoni.

    PubMed

    Chaturvedula, Venkata Sai Prakash; Chen, Steven; Yu, Oliver; Mao, Guohong

    2013-09-30

    From the commercial extract of the leaves of Stevia rebaudiana Bertoni, a minor steviol glycoside, 13-[(2-O-β-D-glucopyranosyl-3-O-β-D-glucopyranosyl-β-D-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid-[(2-O-(3-O-β-D-glucopyranosyl-α-L-rhamnopyranosyl)-3-O-β-D-glucopyranosyl-β-D-glucopyranosyl) ester] (1); also known as rebaudioside O having seven sugar units has been isolated. Its structural characterization has been achieved by the extensive 1D (1H and 13C), and 2D NMR (COSY, HMQC, HMBC) as well as mass spectral data. Further, hydrolysis studies were performed on rebaudioside O using acid and enzymatic methods to identify aglycone and sugar residues in its structure as well as their configurations.

  17. Isolation, NMR Spectral Analysis and Hydrolysis Studies of a Hepta Pyranosyl Diterpene Glycoside from Stevia rebaudiana Bertoni

    PubMed Central

    Chaturvedula, Venkata Sai Prakash; Chen, Steven; Yu, Oliver; Mao, Guohong

    2013-01-01

    From the commercial extract of the leaves of Stevia rebaudiana Bertoni, a minor steviol glycoside, 13-[(2-O-β-d-glucopyranosyl-3-O-β-d-glucopyranosyl-β-d-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid-[(2-O-(3-O-β-d-glucopyranosyl-α-l-rhamnopyranosyl)-3-O-β-d-glucopyranosyl-β-d-glucopyranosyl) ester] (1); also known as rebaudioside O having seven sugar units has been isolated. Its structural characterization has been achieved by the extensive 1D (1H and 13C), and 2D NMR (COSY, HMQC, HMBC) as well as mass spectral data. Further, hydrolysis studies were performed on rebaudioside O using acid and enzymatic methods to identify aglycone and sugar residues in its structure as well as their configurations. PMID:24970189

  18. Anti-ulcer xanthones from the roots of Hypericum oblongifolium Wall.

    PubMed

    Ali, Mumtaz; Latif, Abdul; Zaman, Khair; Arfan, Mohammad; Maitland, Derek; Ahmad, Habib; Ahmad, Manzoor

    2014-06-01

    Three new xanthones, hypericorin C (1), hypericorin D (2) and 3,4-dihydroxy-5-methoxyxanthone (3), along with eight known compounds; 2,3-dimethoxyxanthone (4), 3,4-dihydroxy-2-methoxyxanthone (5), 3,5-dihydroxy-1-methoxyxanthone (6), 3-acetylbetulinic acid (7), 10H-1,3-dioxolo[4,5-b]xanthen-10-one (8), 3-hydroxy-2-methoxyxanthone (9), 3,4,5-trihydroxyxanthone (10) and betulinic acid (11) were isolated from the roots of Hypericum oblongifolium. The structures of the new compounds 1, 2 and 3 were deduced by spectroscopic techniques [ESI MS, (1)H NMR, (13)C NMR, and 2D NMR (HMQC, HMBC, COSY and NOESY)]. The entire series of compounds were evaluated for anti-ulcer activity.

  19. Cytotoxic activity of C-geranyl compounds from Paulownia tomentosa fruits.

    PubMed

    Smejkal, Karel; Babula, Petr; Slapetová, Tereza; Brognara, Eleonora; Dall'acqua, Stefano; Zemlicka, Milan; Innocenti, Gabbriella; Cvacka, Josef

    2008-10-01

    The newly discovered 5,7-dihydroxy-6-geranylchromone ( 1) was isolated from PAULOWNIA TOMENTOSA fruit and subsequently characterized. The structure of the isolated compound was elucidated on the basis of extensive NMR experiments including HMQC, HMBC, COSY, and NOESY, as well as HR-MS, IR, and UV. The cytotoxicity of 1 was evaluated using a plant cell model represented by tobacco BY-2 cells. The other phytoconstituents ( 2 - 8) previously isolated from P. TOMENTOSA were similarly evaluated together with the known flavanones 10 and 11. The cytotoxicity (human erythro-leukaemia cell line K562) and activity on erythroid differentiation of compounds 2 - 9 and 12 and 13 have also been evaluated. Acteoside ( 2) was determined to be the most toxic of the compounds tested on BY-2 cells, diplacone ( 6) on the K562 cell line. Some aspects of the relationship between the flavanone skeleton substitution and the metabolic activation necessary for a toxic effect are discussed.

  20. Structural elucidation of polysaccharide containing 3-O-methyl galactose from fruiting bodies of Pleurotus citrinopileatus.

    PubMed

    He, Pengfei; Zhang, Anqiang; Zhou, Saijing; Zhang, Fuming; Linhardt, Robert J; Sun, Peilong

    2016-11-03

    A water-soluble polysaccharide containing 3-O-methyl galactose (PCP60W) was isolated from fruiting bodies of Pleurotus citrinopileatus and purified by anion-exchange and gel column chromatography. This polysaccharide has an average molecular weight of 2.74 × 10(4) Da and its structure was elucidated using monosaccharide composition and methylation analysis combined with one- and two-dimensional (COSY, TOCSY, NOESY, HMQC and HMBC) NMR spectroscopy. PCP60W was shown to be a linear partially 3-O-methylated α-galactopyranan comprised of 6-linked galactose, 6-linked 3-O-methyl galactose and 4-linked glucose in a ratio of 3.0:1.0:0.6. This work provides additional evidence for the view that 3-O-methyl galactose is common to the genus Pleurotus.

  1. Antisweet saponins from Gymnema sylvestre.

    PubMed

    Ye, W; Liu, X; Zhang, Q; Che, C T; Zhao, S

    2001-02-01

    Three new oleanane-type triterpene glycosides (1-3), along with the sodium salt of alternoside II (4), were isolated from an ethanol extract of the leaves of Gymnema sylvestre. The structures of these new saponins were identified as 21 beta-O-benzoylsitakisogenin 3-O-beta-D-glucopyranosyl(1-->3)-beta-D-glucuronopyranoside (1), the potassium salt of longispinogenin 3-O-beta-D-glucopyranosyl(1-->3)-beta-D-glucuronopyranoside (2), and the potassium salt of 29-hydroxylongispinogenin 3-O-beta-D-glucopyranosyl(1-->3)-beta-D-glucuronopyranoside (3). The aglycon of 3, gymnemagenol (3a), was characterized as 3 beta,16 beta,28, 29-tetrahydroxyolean-12-ene. Structure elucidation was accomplished by interpretation of NMR (DQF-COSY, HMQC, and HMBC) results, FABMS, and hydrolysis. Saponin 1 and the sodium salt of alternoside II (4) exhibited antisweet activity.

  2. Acylated and non-acylated flavonol monoglycosides from the Indian minor spice Nagkesar (Mammea longifolia).

    PubMed

    Jagan Mohan Rao, Lingamallu; Yada, Hiroshi; Ono, Hiroshi; Yoshida, Mitsuru

    2002-05-22

    A methanol extract of nagkesar (buds of Mammea longifolia), which showed strong radical scavenging activity, yielded 13 compounds by separations using column chromatography and HPLC. Structure elucidation of these compounds was achieved by (1)H and (13)C NMR, including DQF-COSY, TOCSY, DEPT, HMQC, HSQC, and HMBC. They include two new compounds, quercetin 3-O-(2' ',4' 'di-E-p-coumaroyl)-alpha-L-rhamno-pyranoside and quercetin 3-O-(3' ',4' '-di-E-p-coumaroyl)-alpha-L-rhamnopyranoside, along with known compounds kaempferol, quercetin, the isopropylidenedioxy derivative of shikimic acid, kaempferol 3-O-(2' ',4' '-di-E-p-coumaroyl)-alpha-L-rhamnopyranoside, kaempferol 3-O-(3' ',4' '-di-E-p-coumaroyl)-alpha-L-rhamnopyranoside, kaempferol 3-O-alpha-L-rhamnopyranoside, quercetin 3-O-alpha-L-rhamnopyranoside, shikimic acid, kaempferol 3-O-beta-D-glucopyranoside, quercetin 3-O-beta-D-glucopyranoside, and beta-sitosterol 3-O-beta-D-glucopyranoside.

  3. Antidepressent Effect of Two New Benzyl Derivatives from Wild Strawberry Fragaria vesca var. nubicola Lindl. ex Hook.f.

    PubMed Central

    Naz, Sadia; Farooq, Umar; Khan, Ajmal; Khan, Haroon; Karim, Nasiara; Sarwar, Rizwana; Hussain, Javid; Rauf, Abdur

    2017-01-01

    Two new benzyl derivatives were isolated from ethyl acetate fraction of wild strawberry, Fragaria vesca var. nubicola Lindl. ex Hook.f. The structures of these compounds were elucidated to be 5-(4-hydroxy-3-methoxyphenethyl)-7-methoxy-2H-chromen-3-ol (1) and 5-(4-hydroxy-3-methoxyphenethyl)-4,7-dimethoxy-2H-chromen-3-ol (2) based on spectroscopic data through IR, UV, 1H-NMR, 13C-NMR along with two dimensional (2D) techniques HMBC, HMQC, and COSY. Both compounds 1 and 2 were studied in tail suspension and forced swim tests for antidepressant like effects. A significant dose dependent antidepressant like effect was observed by causing spontaneous anti-immobility at various test doses upon intraperitoneal administration. PMID:28790915

  4. Constant-time 2D and 3D through-bond correlation NMR spectroscopy of solids under 60 kHz MAS

    PubMed Central

    Zhang, Rongchun; Ramamoorthy, Ayyalusamy

    2016-01-01

    Establishing connectivity and proximity of nuclei is an important step in elucidating the structure and dynamics of molecules in solids using magic angle spinning (MAS) NMR spectroscopy. Although recent studies have successfully demonstrated the feasibility of proton-detected multidimensional solid-state NMR experiments under ultrafast-MAS frequencies and obtaining high-resolution spectral lines of protons, assignment of proton resonances is a major challenge. In this study, we first re-visit and demonstrate the feasibility of 2D constant-time uniform-sign cross-peak correlation (CTUC-COSY) NMR experiment on rigid solids under ultrafast-MAS conditions, where the sensitivity of the experiment is enhanced by the reduced spin-spin relaxation rate and the use of low radio-frequency power for heteronuclear decoupling during the evolution intervals of the pulse sequence. In addition, we experimentally demonstrate the performance of a proton-detected pulse sequence to obtain a 3D 1H/13C/1H chemical shift correlation spectrum by incorporating an additional cross-polarization period in the CTUC-COSY pulse sequence to enable proton chemical shift evolution and proton detection in the incrementable t1 and t3 periods, respectively. In addition to through-space and through-bond 13C/1H and 13C/13C chemical shift correlations, the 3D 1H/13C/1H experiment also provides a COSY-type 1H/1H chemical shift correlation spectrum, where only the chemical shifts of those protons, which are bonded to two neighboring carbons, are correlated. By extracting 2D F1/F3 slices (1H/1H chemical shift correlation spectrum) at different 13C chemical shift frequencies from the 3D 1H/13C/1H spectrum, resonances of proton atoms located close to a specific carbon atom can be identified. Overall, the through-bond and through-space homonuclear/heteronuclear proximities determined from the 3D 1H/13C/1H experiment would be useful to study the structure and dynamics of a variety of chemical and biological

  5. Complete structure of the cell surface polysaccharide of Streptococcus oralis ATCC 10557: A receptor for lectin-mediated interbacterial adherence

    SciTech Connect

    Abeygunawardana, C.; Bush, C.A. ); Cisar, J.O. )

    1991-07-02

    Lectin-carbohydrate binding is known to play an important role in a number of different cell-cell interactions including those between certain species of oral streptococci and actinomyces that colonize teeth. The cell wall polysaccharides of Streptococcus oralis ATCC 10557, S. oralis 34, and Streptococcus mitis J22, although not identical antigenically, each function as a receptor molecule for the galactose and N-acetylgalactosamine reactive fimbrial lectins of Actinomyces viscosus and Actinomyces naeslundii. Carbohydrate analysis of the receptor polysaccharide isolated from S. oralis ATCC 10557 shows galactose (3 mol), glucose (1 mol), GalNAc (1 mol), and rhamnose (1 mol). {sup 1}H NMR spectra of the polysaccharide show that is partially O-acetylated. Analysis of the {sup 1}H NMR spectrum of the de-O-acetylated polysaccharide shows that it is composed of repeating subunits containing six monosaccharides and that the subunits are joined by a phosphodiester linkage. The {sup 1}H and {sup 13}C NMR spectra were completely assigned by two-dimensional homonuclear correlation methods and by {sup 1}H-detected heteronuclear multiple-quantum correlation ({sup 1}H({sup 13}C)HMQC). The complete {sup 1}H and {sup 13}C assignment of the native polysaccharide was carried out by the same techniques augmented by a {sup 13}C-coupled hybrid HMQC-COSY method, which is shown to be especially useful for carbohydrates in which strong coupling and overlapping peaks in the {sup 1}H spectrum pose difficulties.

  6. The use of a selective saturation pulse to suppress t1 noise in two-dimensional 1H fast magic angle spinning solid-state NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Robertson, Aiden J.; Pandey, Manoj Kumar; Marsh, Andrew; Nishiyama, Yusuke; Brown, Steven P.

    2015-11-01

    A selective saturation pulse at fast magic angle spinning (MAS) frequencies (60+ kHz) suppresses t1 noise in the indirect dimension of two-dimensional 1H MAS NMR spectra. The method is applied to a synthetic nucleoside with an intense methyl 1H signal due to triisopropylsilyl (TIPS) protecting groups. Enhanced performance in terms of suppressing the methyl signal while minimising the loss of signal intensity of nearby resonances of interest relies on reducing spin diffusion - this is quantified by comparing two-dimensional 1H NOESY-like spin diffusion spectra recorded at 30-70 kHz MAS. For a saturation pulse centred at the methyl resonance, the effect of changing the nutation frequency at different MAS frequencies as well as the effect of changing the pulse duration is investigated. By applying a pulse of duration 30 ms and nutation frequency 725 Hz at 70 kHz MAS, a good compromise of significant suppression of the methyl resonance combined with the signal intensity of resonances greater than 5 ppm away from the methyl resonance being largely unaffected is achieved. The effectiveness of using a selective saturation pulse is demonstrated for both homonuclear 1H-1H double quantum (DQ)/single quantum (SQ) MAS and 14N-1H heteronuclear multiple quantum coherence (HMQC) two-dimensional solid-state NMR experiments.

  7. Studies of minute quantities of natural abundance molecules using 2D heteronuclear correlation spectroscopy under 100 kHz MAS.

    PubMed

    Nishiyama, Y; Kobayashi, T; Malon, M; Singappuli-Arachchige, D; Slowing, I I; Pruski, M

    2015-01-01

    Two-dimensional (1)H{(13)C} heteronuclear correlation solid-state NMR spectra of naturally abundant solid materials are presented, acquired using the 0.75-mm magic angle spinning (MAS) probe at spinning rates up to 100 kHz. In spite of the miniscule sample volume (290 nL), high-quality HSQC-type spectra of bulk samples as well as surface-bound molecules can be obtained within hours of experimental time. The experiments are compared with those carried out at 40 kHz MAS using a 1.6-mm probe, which offered higher overall sensitivity due to a larger rotor volume. The benefits of ultrafast MAS in such experiments include superior resolution in (1)H dimension without resorting to (1)H-(1)H homonuclear RF decoupling, easy optimization, and applicability to mass-limited samples. The HMQC spectra of surface-bound species can be also acquired under 100 kHz MAS, although the dephasing of transverse magnetization has significant effect on the efficiency transfer under MAS alone. Published by Elsevier Inc.

  8. The use of a selective saturation pulse to suppress t1 noise in two-dimensional (1)H fast magic angle spinning solid-state NMR spectroscopy.

    PubMed

    Robertson, Aiden J; Pandey, Manoj Kumar; Marsh, Andrew; Nishiyama, Yusuke; Brown, Steven P

    2015-11-01

    A selective saturation pulse at fast magic angle spinning (MAS) frequencies (60+kHz) suppresses t1 noise in the indirect dimension of two-dimensional (1)H MAS NMR spectra. The method is applied to a synthetic nucleoside with an intense methyl (1)H signal due to triisopropylsilyl (TIPS) protecting groups. Enhanced performance in terms of suppressing the methyl signal while minimising the loss of signal intensity of nearby resonances of interest relies on reducing spin diffusion--this is quantified by comparing two-dimensional (1)H NOESY-like spin diffusion spectra recorded at 30-70 kHz MAS. For a saturation pulse centred at the methyl resonance, the effect of changing the nutation frequency at different MAS frequencies as well as the effect of changing the pulse duration is investigated. By applying a pulse of duration 30 ms and nutation frequency 725 Hz at 70 kHz MAS, a good compromise of significant suppression of the methyl resonance combined with the signal intensity of resonances greater than 5 ppm away from the methyl resonance being largely unaffected is achieved. The effectiveness of using a selective saturation pulse is demonstrated for both homonuclear (1)H-(1)H double quantum (DQ)/single quantum (SQ) MAS and (14)N-(1)H heteronuclear multiple quantum coherence (HMQC) two-dimensional solid-state NMR experiments.

  9. New acylated anthocyanins and other flavonoids from the red flowers of Clematis cultivars.

    PubMed

    Hashimoto, Masanori; Suzuki, Toshisada; Iwashina, Tsukasa

    2011-11-01

    Six new acylated cyanidin glycosides, cyanidin 3-O-beta-(2''-E-caffeoylglucopyranosyl)-(1 --> 2)-O-beta-galactopyranoside (1), cyanidin 3-O-beta-(2''-E-caffeoylglucopyranosyl)-(1 --> 2)-O-beta-(6''-malonylgalactopyranoside) (2), cyanidin 3-O-beta-(2''-E-caffeoylglucopyranosyl)-(1 --> 2)-O-beta-(6''-succinylgalactopyranoside) (3), cyanidin 3-O-beta-(2''-E-caffeoylglucopyranosyl)-(1 --> 2)-O-beta-galactopyranoside-3''- O-beta-glucuronopyranoside (4), cyanidin 3-O-beta-(2''-E-caffeoylglucopyranosyl)-(1 --> 2)-O-beta-(6''-malonylgalactopyranoside)-3'-O-beta-glucuronopyranoside (5), and cyanidin 3-O-beta-(2'-E-feruloylglucopyranosyl)-(1 --> 2)-O-beta-(6''-malonylgalactoside)-3' -O-beta-glucuronopyranoside (6), were isolated from the red flowers of two Clematis cultivars, 'Niobe'and 'Madame Julia Correvon'. The chemical structures of the isolated anthocyanins were determined by UV, LC-MS, HPLC, TLC, characterization of hydrolysates, and 1H and 13C NMR spectroscopy, including H-H COSY, C-H COSY, HMBC, HMQC and NOESY. The last three anthocyanins were widely distributed in 37 red flower Clematis cultivars. On the other hand, the first three compounds were found only in two cultivars. Five known flavonol glycosides, kaempferol 3-O-glucoside, kaempferol 3-O-rutinoside, quercetin 3-O-galactoside, quercetin 3-O-glucoside and quercetin 3-O-rutinoside, were isolated from the flowers of'Madame Julia Correvon'.

  10. Determination of size and sign of hetero-nuclear coupling constants from 2D 19F-13C correlation spectra

    NASA Astrophysics Data System (ADS)

    Ampt, Kirsten A. M.; Aspers, Ruud L. E. G.; Dvortsak, Peter; van der Werf, Ramon M.; Wijmenga, Sybren S.; Jaeger, Martin

    2012-02-01

    Fluorinated organic compounds have become increasingly important within the polymer and the pharmaceutical industry as well as for clinical applications. For the structural elucidation of such compounds, NMR experiments with fluorine detection are of great value due to the favorable NMR properties of the fluorine nucleus. For the investigation of three fluorinated compounds, triple resonance 2D HSQC and HMBC experiments were adopted to fluorine detection with carbon and/or proton decoupling to yield F-C, F-C{H}, F-C{Cacq} and F-C{H,Cacq} variants. Analysis of E.COSY type cross-peak patterns in the F-C correlation spectra led, apart from the chemical shift assignments, to determination of size and signs of the JCH, JCF, and JHF coupling constants. In addition, the fully coupled F-C HMQC spectrum of steroid 1 was interpreted in terms of E.COSY type patterns. This example shows how coupling constants due to different nuclei can be determined together with their relative signs from a single spectrum. The analysis of cross-peak patterns, as presented here, not only provides relatively straightforward routes to the determination of size and sign of hetero-nuclear J-couplings in fluorinated compounds, it also provides new and easy ways for the determination of residual dipolar couplings and thus for structure elucidation. The examples and results presented in this study may contribute to a better interpretation and understanding of various F-C correlation experiments and thereby stimulate their utilization.

  11. Isolation of biologically active constituents from Moringa peregrina (Forssk.) Fiori. (family: Moringaceae) growing in Egypt.

    PubMed

    El-Alfy, Taha S; Ezzat, Shahira M; Hegazy, Ahmed K; Amer, Aziza M M; Kamel, Gehan M

    2011-04-01

    Moringa peregrina is a wild plant that grown in the eastern desert mountains in Egypt. Although, this plant is native to Egypt, no details studies were traced on its chemical composition and biological activity. The different fractions of the ethanolic extract of the dried aerial parts of the plants were subjected to fractionation and purification on various silica and sephadex columns for the isolation of the major compounds which were tested for there anticancer activity. The aqueous and ethanolic extract as well as its different fractions were tested for antihyperglycemic effect on Streptozitocin-induced diabetes in rats. Investigation of the different fractions of the ethanolic extract of the aerial parts of M. peregrina yielded lupeol acetate (1), β-amyrin (2), α-amyrin (3), β-sitosterol (4), β-sitosterol-3-O-glucoside (5), apigenin (6), rhamnetin (7), neochlorogenic acid (10), rhamnetin-3-O-rutinoside (12), and 6-methoxy-acacetin-8-C-β-glucoside (13) which were isolated for the first time from the plant. Compound (13) was isolated for the first time from genus Moringa. In addition, quercetin (8), chryseriol-7-O-rhamnoside (9) and quercetin-3-O-rutinoside (11) were also isolated. Identification has been established by spectral data (UV, MS, IR, 1H, 1H -1H COSY, and 13C-NMR). The major isolated compounds were found to have valuable cytotoxic activities against breast (MCF 7) and colon (HCT 116) cancer cell lines and their activities were comparable to the reference drug doxorubicin. On the other hand, the aqueous and ethanolic extracts as well as the n-hexane fraction were found to have potent antihyperglycemic effect on Streptozitocin-induced diabetes in rats. The Egyptian plant M. peregrina is rich in biologically active ingredients which showed potent cytotoxic activity and also its ethanolic extraxt exert a significant antihyperglycemic effect.

  12. Isolation of biologically active constituents from Moringa peregrina (Forssk.) Fiori. (family: Moringaceae) growing in Egypt

    PubMed Central

    El-Alfy, Taha S.; Ezzat, Shahira M.; Hegazy, Ahmed K.; Amer, Aziza M. M.; Kamel, Gehan M.

    2011-01-01

    Background: Moringa peregrina is a wild plant that grown in the eastern desert mountains in Egypt. Although, this plant is native to Egypt, no details studies were traced on its chemical composition and biological activity. Materials and Methods: The different fractions of the ethanolic extract of the dried aerial parts of the plants were subjected to fractionation and purification on various silica and sephadex columns for the isolation of the major compounds which were tested for there anticancer activity. The aqueous and ethanolic extract as well as its different fractions were tested for antihyperglycemic effect on Streptozitocin-induced diabetes in rats. Results: Investigation of the different fractions of the ethanolic extract of the aerial parts of M. peregrina yielded lupeol acetate (1), β-amyrin (2), α-amyrin (3), β-sitosterol (4), β-sitosterol-3-O-glucoside (5), apigenin (6), rhamnetin (7), neochlorogenic acid (10), rhamnetin-3-O-rutinoside (12), and 6-methoxy-acacetin-8-C-β-glucoside (13) which were isolated for the first time from the plant. Compound (13) was isolated for the first time from genus Moringa. In addition, quercetin (8), chryseriol-7-O-rhamnoside (9) and quercetin-3-O-rutinoside (11) were also isolated. Identification has been established by spectral data (UV, MS, IR, 1H, 1H -1H COSY, and 13C-NMR). The major isolated compounds were found to have valuable cytotoxic activities against breast (MCF 7) and colon (HCT 116) cancer cell lines and their activities were comparable to the reference drug doxorubicin. On the other hand, the aqueous and ethanolic extracts as well as the n-hexane fraction were found to have potent antihyperglycemic effect on Streptozitocin-induced diabetes in rats. Conclusion: The Egyptian plant M. peregrina is rich in biologically active ingredients which showed potent cytotoxic activity and also its ethanolic extraxt exert a significant antihyperglycemic effect. PMID:21716619

  13. Double Unknown Microscale Preparation and COSY Analysis of an Unknown Ester: An Introductory 2D-NMR Experiment

    NASA Astrophysics Data System (ADS)

    Branz, Stephen E.; Miele, Robert G.; Okuda, Roy K.; Straus, Daniel A.

    1995-07-01

    2D-NMR experiments are becoming more commonplace for organic analysis and promise to become as routine for chemists of this decade as 1D-NMR experiments were for chemists of the 1970's. However, undergraduate students seldom if ever are exposed to such experiments despite the increasing availability of high-field, superconducting magnets, more powerful computers, and menu driven software that is extremely friendly. This article outlines an experiment that integrates NMR into the organic teaching laboratory in a way designed to highlight the power of the technique and not merely to confirm the identity of known substances.

  14. Materials Data on Na2Co(Si2O5)2 (SG:2) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  15. Quantifying the hydrogen-bonding interaction between cation and anion of pure [EMIM][Ac] and evidencing the ion pairs existence in its extremely diluted water solution: Via 13C, 1H, 15N and 2D NMR

    NASA Astrophysics Data System (ADS)

    Chen, Yu; Li, Shehong; Xue, Zhimin; Hao, Mingyang; Mu, Tiancheng

    2015-01-01

    The acetate-based ionic liquid (AcIL) [EMIM][Ac] does not fully dissociated into isolated ions in extremely diluted water solution (0.5 mol% of IL). Still, ion pairs exist via the through-space weak van der Waals force between H6 of the cation and Hb of the anion. In this ion pairs, except for H6 and Hb, all other hydrogen atoms (i.e., H2, H4, H5, H7, H8) are totally hydrated by water; the acetate anion suffers from a more extent of hydration due to its higher hydrophilicity. One dimension (1D) nuclear magnetic resonance (NMR) (1H, 13C, 15N,) and two dimensions (2D) NMR are used in this study. 2D NMR used includes through-space 1H-1H NOSEY (nuclear Overhauser effect spectroscopy), through-bond 1H-13C HSQC COSY (heteronuclear single-quantum correlation spectroscopy), and HMBC COSY (heteronuclear multiple-bond correlation spectroscopy). The much stronger (H245/anion) or weaker (H78/anion) hydrogen-bonding interaction in the pure [EMIM][Ac] disfavors the association of ions in the diluted state due to a better hydrogen-bonding donor or a weaker hydrogen-bonding strength, respectively. However, H6/anion with the moderate hydrogen-bonding strength and the moderate hydrogen-bonding donating ability existed in the pure [EMIM][Ac] plays the role in determining the associating ion pairs. The proportion of hydrogen-bonding interaction between hydrogens in the cation with anion (100%) is approximately quantified in descending order as follows: H2 (42%), H4 (24%), H5 (22%), H6 (6%), H7 (5%), and H8 (1%).

  16. Two pairs of rare naturally occurring 4-hydroxy-4-methyl-2,5-heptanedione derivatives from the red alga Chondria crassicaulis.

    PubMed

    Tong, Lin; Zhang, Yi; Liu, Ai-Hong; Yao, Li-Gong; Guo, Yue-Wei; Mao, Shui-Chun; Wang, Bin

    2017-06-01

    Two pairs of rare naturally occurring racemic lipids, (±)-4,7-dihydroxy-4-methyl-2,5-heptanedione (1), and (±)-7-butoxy-4-hydroxy-4-methyl-2,5-heptanedione (2) were isolated from the red alga Chondria crassicaulis Harv. The structures of the racemic mixtures of 1 and 2 were elucidated by detailed spectroscopic techniques, including 1D and 2D NMR ((1)H and (13)C NMR, (1)H-(1)H COSY, HSQC, and HMBC) as well as mass spectrometry and optical rotation experiments, and by comparison with data for related known analogs. This is the first report of naturally occurring 4-hydroxy-4-methyl-2,5-heptanedione derivatives. Antifungal, PTP1B inhibitory, and receptor tyrosine kinase inhibitory activities of these two compounds were investigated. The results showed that compounds 1 and 2 exhibited good selective inhibition against RET tyrosine kinase activity with IC50 values of 9.56 and 8.93 μM, respectively. Compound 1 also displayed moderate antifungal activity against Cryptococcus neoformans (32609), showing a MIC80 value of 32 μg/ml.

  17. The structure and immunoreactivity of exopolysaccharide isolated from Lactobacillus johnsonii strain 151.

    PubMed

    Górska-Frączek, Sabina; Sandström, Corine; Kenne, Lennart; Paściak, Mariola; Brzozowska, Ewa; Strus, Magdalena; Heczko, Piotr; Gamian, Andrzej

    2013-08-30

    The exopolysaccharide (EPS) structure from Lactobacillus johnsonii strain 151 isolated from the intestinal tract of mice was investigated. Sugar and methylation analyses together with (1)H and (13)C NMR spectroscopy, including two-dimensional (1)H,(1)H COSY, TOCSY, NOESY, and (1)H,(13)C HSQC, HMBC experiments, revealed that the repeating unit of the EPS is the linear pentasaccharide: →6)-α-d-Galp-(1→6)-α-d-Glcp-(1→3)-β-d-Galf-(1→3)-α-d-Glcp-(1→2)-β-d-Galf-(1→ The immunoreactivity of two structurally different exopolysaccharides isolated from L. johnsonii, 151 and 142 (Carbohydr. Res. 2010, 345, 108-114), was compared. Both EPSs differed in their reactivity with antisera. EPS from L. johnsonii 151 reacted with anti-Lactobacillus polyclonal sera against cells of five different strains, while EPS from L. johnsonii 142 was found to react only with its own antiserum. The broader specificity and higher reactivity of EPS from 151 strain than EPS from 142 strain were also observed with human sera. The physiological antibodies recognizing polysaccharide antigens were present in both adults and umbilical cord blood sera. A highly specific EPS 142 bearing strain was isolated from experimentally induced inflammatory bowel disease (IBD) mice, while a strain with EPS 151 isolated from the intestinal tract of healthy mice is characterized by a broad immune reactivity common structure.

  18. One pot synthesis of Curcumin-NSAIDs prodrug, spectroscopic characterization, conformational analysis, chemical reactivity, intramolecular interactions and first order hyperpolarizability by DFT method

    NASA Astrophysics Data System (ADS)

    Srivastava, Sangeeta; Gupta, Preeti; Sethi, Arun; Singh, Ranvijay Pratap

    2016-08-01

    A novel Curcumin-NSAIDs prodrug 4-((1E, 3Z, 6E)-3-hydroxy-(4-hydroxy-3-methoxyphenyl)-5-oxohepta-1,3,3-trienyl)-2-methoxyphenyl-2-(4-isobutylphenyl) propanoate (2) derivative was synthesized by Steglich esterification in high yield and characterized with the help of 1H, 13C NMR, 1H-1H COSY, UV, FT-IR spectroscopy and mass spectrometry. The molecular geometry of synthesized compound was calculated in ground state by Density functional theory (DFT/B3LYP) using two different basis set 6-31G (d, p) and 6-311G (d, p). Conformational analysis of 2 was carried out to determine the most stable conformation. Stability of the molecule as a result of hyperconjugative interactions and electron delocalization were analysed using Natural bond orbital (NBO) analysis. Intramolecular interactions were analysed by AIM (Atom in molecule) approach. Global and local reactivity descriptors were calculated to study the reactive site within molecule. The electronic properties such as HOMO and LUMO energies were calculated using time dependent Density Functional Theory (TD-DFT). The vibrational wavenumbers were calculated using DFT method and assigned with the help of potential energy distribution (PED). First hyperpolarizability value has been calculated to describe the nonlinear optical (NLO) property of the synthesized compound. Molecular electrostatic potential (MEP) for synthesized compounds have also been determined to check their electrophilic or nucleophilic reactivity.

  19. Glycosylation of aromatic amines I: Characterization of reaction products and kinetic scheme.

    PubMed

    Gokhale, Madhushree Y; Kearney, William R; Kirsch, Lee E

    2009-01-01

    The reactions of aliphatic and aromatic amines with reducing sugars are important in both drug stability and synthesis. The formation of glycosylamines in solution, the first step in the Maillard reaction, does not typically cause browning but results in decreased potency and is hence significant from the aspect of drug instability. The purpose of this research was to present (1) unreported ionic equilibria of model reactant (kynurenine), (2) the analytical methods used to characterize and measure reaction products, (3) the kinetic scheme used to measure reaction rates and (4) relevant properties of various reducing sugars that impact the reaction rate in solution. The methods used to identify the reversible formation of two products from the reaction of kynurenine and monosaccharides included LC mass spectrometry, UV spectroscopy, and 1-D and 2-D (1)H-(1)H COSY NMR spectroscopy. Kinetics was studied using a stability-indicating HPLC method. The results indicated the formation of alpha and beta glycosylamines by a pseudo first-order reversible reaction scheme in the pH range of 1-6. The forward reaction was a function of initial glucose concentration but not the reverse reaction. It was concluded that the reaction kinetics and equilibrium concentrations of the glycosylamines were pH-dependent and also a function of the acyclic content of the reacting glucose isomer.

  20. A new flavonol glycoside from the medicinal halophyte Suaeda fruticosa.

    PubMed

    Oueslati, Samia; Ksouri, Riadh; Pichette, André; Lavoie, Serge; Girard-Lalancette, Karl; Mshvildadze, Vakhtang; Abdelly, Chedly; Legault, Jean

    2014-01-01

    A new flavonol glycoside, namely 3-(α-rhamnopyranosyl-(1 → 2)-[β-xylopyranosyl-(1 → 6)]-β-glucopyranosyloxy) isorhamnetin was reported from methanol extracts of aerial parts of Suaeda fruticosa for the first time. In this work, liquid chromatography coupled to atmospheric pressure chemical ionisation mass spectrometry, high-resolution mass spectrometry and nuclear magnetic resonance spectroscopy were used to identify this new compound. Structure was elucidated on the basis of extensive spectroscopic analysis, including HSQC, HMBC and (1)H-(1)H COSY. Antioxidant potentialities of a pure compound were evaluated. The estimation of antioxidant capacities using oxygen radical absorbance capacity (ORAC method) and a cell based-assay (WS1) indicated that this new flavonol exhibited the highest antioxidant activities with an ORAC value of 5.0 ± 0.3 μmol Trolox/μmol and inhibited the tBH-induced oxidation of 2',7'-dichlorofluorescin with an IC50 value of 4.9 ± 0.6 μM.

  1. A new anthraquinone and eight constituents from Hedyotis caudatifolia Merr. et Metcalf: isolation, purification and structural identification.

    PubMed

    Luo, Peng; Su, Jiale; Zhu, Yilin; Wei, Jianhua; Wei, Wanxing; Pan, Weigao

    2016-10-01

    Hedyotis caudatifolia Merr. et Metcalf. (HC), a folk medicine in Yao nationalities areas in China, was used to investigate the chemical constituents. Through silica gel and Sephadex LH-20 column chromatography, nine compounds were isolated and purified. By physical and chemical properties, IR, MS (EI-MS, high resolution EI-MS), 1D NMR ((1)H NMR, (13)C NMR) and 2D NMR (HSQC, (1)H-(1)H COSY, HMBC), their structures were identified as β-sitosterol (1), stigmasterol (2), scopolin (3), 2-hydroxy-1,7,8-trimethoxyanthracene-9,10-dione (4), oleanolic acid (5), ursolic acid (6), methyl barbinervate (7), β-daucosterol (8) and p-Hydroxybenzoic acid (9). These compounds were isolated from HC for the first time, and 4 a new anthraquinone whose biological activities are worth to be investigated in future. These compounds may contribute to the HC's pharmacological effects on treating diseases, and may be used as candidates for control index in establishing the quality control standard of HC.

  2. The Effect of Substituent, Degree of Acetylation and Positioning of the Cationic Charge on the Antibacterial Activity of Quaternary Chitosan Derivatives

    PubMed Central

    Sahariah, Priyanka; Gaware, Vivek S.; Lieder, Ramona; Jónsdóttir, Sigríður; Hjálmarsdóttir, Martha Á.; Sigurjonsson, Olafur E.; Másson, Már

    2014-01-01

    A series of water-soluble cationic chitosan derivatives were prepared by chemoselective functionalization at the amino group of five different parent chitosans having varying degrees of acetylation and molecular weight. The quaternary moieties were introduced at different alkyl spacer lengths from the polymer backbone (C-0, C-2 and C-6) with the aid of 3,6-di-O-tert-butyldimethylsilyl protection of the chitosan backbone, thus allowing full (100%) substitution of the free amino groups. All of the derivatives were characterized using 1H-NMR, 1H-1H COSY and FT-IR spectroscopy, while molecular weight was determined by GPC. Antibacterial activity was investigated against Gram positive S. aureus and Gram negative E. coli. The relationship between structure and activity/toxicity was defined, considering the effect of the cationic group’s structure and its distance from the polymer backbone, as well as the degree of acetylation within a molecular weight range of 7–23 kDa for the final compounds. The N,N,N-trimethyl chitosan with 100% quaternization showed the highest antibacterial activity with moderate cytotoxicity, while increasing the spacer length reduced the activity. Trimethylammoniumyl quaternary ammonium moieties contributed more to activity than 1-pyridiniumyl moieties. In general, no trend in the antibacterial activity of the compounds with increasing molecular weight or degree of acetylation up to 34% was observed. PMID:25196937

  3. Odisolane, a Novel Oxolane Derivative, and Antiangiogenic Constituents from the Fruits of Mulberry (Morus alba L.).

    PubMed

    Lee, Seoung Rak; Park, Jun Yeon; Yu, Jae Sik; Lee, Sung Ok; Ryu, Ja-Young; Choi, Sang-Zin; Kang, Ki Sung; Yamabe, Noriko; Kim, Ki Hyun

    2016-05-18

    Mulberry, the fruit of Morus alba L., is known as an edible fruit and commonly used in Chinese medicines as a warming agent and as a sedative, tonic, laxative, odontalgic, expectorant, anthelmintic, and emetic. Systemic investigation of the chemical constituents of M. alba fruits led to the identification of a novel oxolane derivative, (R*)-2-((2S*,3R*)-tetrahydro-2-hydroxy-2-methylfuran-3-yl)propanoic acid (1), namely, odisolane, along with five known heterocyclic compounds (2-6). The structure of the new compound was elucidated on the basis of HR-MS, 1D and 2D NMR ((1)H-(1)H COSY, HSQC, HMBC, and NOESY) data analysis. Compound 1 has a novel skeleton that consists of 8 carbon units with an oxolane ring, which until now has never been identified in natural products. The isolated compounds were subjected to several activity tests to verify their biological function. Among them, compounds 1, 3, and 5 significantly inhibited cord formation in HUVECs. The action mechanism of compound 3, which had the strongest antiangiogenic activity, was mediated by decreasing VEGF, p-Akt, and p-ERK protein expression. These results suggest that compounds isolated from M. alba fruits might be beneficial in antiangiogenesis therapy for cancer treatment.

  4. Purification and identification of two antifungal cyclic dipeptides from Bacillus cereus subsp. thuringiensis associated with a rhabditid entomopathogenic nematode especially against Fusarium oxysporum.

    PubMed

    Kumar, S Nishanth; Nambisan, Bala; Mohandas, C

    2014-04-01

    The cell-free culture filtrate of Bacillus cereus subsp. thuringiensis associated with an entomopathogenic nematode (EPN), Rhabditis (Oscheius) sp., exhibited strong antimicrobial activity. The ethyl acetate extract of the bacterial culture filtrate was purified by silica gel column chromatography to obtain two cyclic dipeptides (CDPs). The structure and absolute stereochemistry of this compound were determined based on extensive spectroscopic analyses (FABMS, (1)H NMR, (13)C NMR, (1)H-(1)H COSY, (1)H-(13)C HMBC) and Marfey's method. The compounds were identified as cyclo(D-Pro-L-Met) and cyclo(D-Pro-D-Tyr). CDPs showed significantly higher activity than the standard fungicide bavistin against agriculturally important fungi, viz., Fusarium oxysporum, Rhizoctonia solani and Penicillium expansum. The highest activity of 2 µg/ml by cyclo(D-Pro-D-Tyr) was recorded against F. oxysporum, a plant pathogen responsible for causing fusarium wilt followed by R. solani, a pathogen that causes root rot and P. expansum. To our knowledge, this is the first report on the isolation of these compounds from Rhabditis EPN bacterial strain Bacillus cereus subsp. thuringiensis.

  5. Preparative isolation and purification of cuminaldehyde and p-menta-1,4-dien-7-al from the essential oil of Cuminum cyminum L. by high-speed counter-current chromatography.

    PubMed

    Chen, Qinqin; Hu, Xuefang; Li, Jingming; Liu, Ping; Yang, Yang; Ni, Yuanying

    2011-03-09

    High-speed counter-current chromatography (HSCCC) technique in semi-preparative scale was successfully used in isolation and purification of cuminaldehyde and p-menta-1,4-dien-7-al from the essential oil of Cuminum cyminum L. by using a two-phase solvent system composed of n-hexane-methanol-water (5:4:1, v/v/v). The targeted compounds were isolated, collected, purified by HSCCC in the head-tail mode, and then analyzed by gas chromatography (GC). A total of 12.72 ± 0.22 mg of cuminaldehyde and 10.61 ± 0.27 mg of p-menta-1,4-dien-7-al were obtained from 50 mg of the essential oil of C. cyminum L. in less than 6 h, with purities of 95.42% and 97.21%, respectively. In addition to GC-EI/MS, the identity of the cuminaldehyde was further confirmed with the retention time using the method of standard addition, while, the structural identification of p-menta-1,4-dien-7-al was performed with GC-EI/MS, (1)H NMR and (1)H-(1)H COSY.

  6. Amaryllidaceae alkaloids with new framework types from Zephyranthes candida as potent acetylcholinesterase inhibitors.

    PubMed

    Zhan, Guanqun; Liu, Junjun; Zhou, Junfei; Sun, Bin; Aisa, Haji Akber; Yao, Guangmin

    2017-02-15

    Three new Amaryllidaceae alkaloids, named zephycandidines I-III (1-3), were isolated from Zephyranthes candida. The structures of 1-3 were elucidated by spectroscopic analyses including HRESIMS, (1)H NMR, (13)C NMR, DEPT, HSQC, (1)H-(1)H COSY, HMBC, ROESY, and electronic circular dichroism (ECD), as well as ECD calculation. The absolute configuration of 1 was finally established by single crystal X-ray diffraction using Cu Kα radiation. Zephycandidines I (1) and III (3) with new framework types represent the first example of 7-phenyl-hexahydroindole and 5,2'-dimethyl-biphenyl-2-ylamine alkaloids, respectively, and their plausible biosynthetic pathway are proposed. Zephycandidine II (2) is the first C3a-phenyl-hexahydroindole type alkaloid isolated from the genus of Zephyranthes. These new alkaloids 1-3 were evaluated for their acetylcholinesterase (AChE) inhibitory activities, and 3 showed potent AChE inhibitory activity with an IC50 value of 8.82 μM, suggesting that the framework of 5,2'-dimethyl-biphenyl-2-ylamine in 3 may be a potential group for the AChE inhibitory activity. The docking studies of 1-3 and galanthamine with AChE revealed that interactions with W286 and Y337 are necessary for the AChE inhibitory activity.

  7. Hyphenation of capillary HPLC to microcoil (1)H NMR spectroscopy for the determination of tocopherol homologues.

    PubMed

    Krucker, Manfred; Lienau, Annette; Putzbach, Karsten; Grynbaum, Marc David; Schuler, Paul; Albert, Klaus

    2004-05-01

    Highly selective reversed phases (C(30) phases) are self-packed in 250 microm inner diameter fused-silica capillaries and employed for capillary HPLC separation of shape-constrained natural compounds (tocopherol homologues, vitamin E). Miniaturized hyphenated systems such as capillary HPLC-ESI-MS (positive ionization mode) and, with special emphasis, continuous-flow capillary HPLC- NMR are used for structural determination of the separated compounds. Despite the small amount of sample available (1.33 microg of each tocopherol), the authors have been able to monitor the capillary HPLC separation under continuous-flow (1)H NMR conditions, thus allowing an immediate peak identification. Further structural assignment was carried out in the stopped-flow NMR mode as shown, for example, by a 2D (1)H,(1)H COSY NMR spectrum of alpha-tocopherol. We demonstrate in this paper the considerable potential of hyphenated capillary separations coupled to MS and NMR for the investigation of restricted amounts of sample.

  8. Use of NMR-Based Metabolomics To Chemically Characterize the Roasting Process of Chicory Root.

    PubMed

    Wei, Feifei; Furihata, Kazuo; Zhang, Mimin; Miyakawa, Takuya; Tanokura, Masaru

    2016-08-16

    Roasted chicory root (Cichorium intybus) has been widely accepted as the most important coffee substitute. In this study, a nuclear magnetic resonance (NMR)-based comprehensive analysis was performed to monitor the substantial changes in the composition of chicory root during the roasting process. A detailed signal assignment of dried raw and roasted chicory roots was carried out using (1)H, (13)C, (1)H-(1)H DQF-COSY, (1)H-(13)C edited-HSQC, (1)H-(13)C CT-HMBC, and (1)H-(13)C HSQC-TOCSY NMR spectra. On the basis of the signal assignments, 36 NMR-visible components were monitored simultaneously during roasting. Inulins, sucrose, and most of the amino acids were largely degraded during the roasting process, whereas monosaccharides decreased at the beginning and then increased until the dark roasting stage. Acetamide, 5-hydroxymethylfurfural, di-d-fructose dianhydride, and norfuraneol were newly formed during roasting. Furthermore, a principal component analysis score plot indicated that similar chemical composition profiles could be achieved by roasting the chicory root either at a higher firepower for a shorter time or at a lower firepower for a longer time.

  9. Isolation of brassicasterol, its synthetic prodrug-crystal structure, stereochemistry and theoretical studies

    NASA Astrophysics Data System (ADS)

    Sethi, Arun; Prakash, Rohit; Srivastava, Sangeeta; Amandeep; Bishnoi, Abha; Singh, Ranvijay Pratap

    2014-07-01

    In the present study brassicasterol (1), was isolated from the chloroform extract of the flowers of Allamanda violacea and identified with the help of different spectroscopic techniques like 1H, 13C, 2D NMR (1H-1H COSY), IR, UV and mass spectrometry. A novel prodrug was synthesized by carrying out esterification of brassicasterol (1) with the well known drug naproxen using Steglich esterification to give 3β-(2-(6-methoxynaphthalene-2yl) propionoxy) 24 methyl cholest-5, 22-dien (2). Compounds 2 was subjected to single crystal X-ray diffraction technique and crystallized out in monoclinic form having P21 space group and stabilized by CH-π interactions. Structure and stereochemistry of compound 2 was established with the help of modern spectroscopic techniques like 1H NMR, IR, UV, mass spectrometry as well as with single crystal X-ray diffraction. Molecular geometry and vibrational frequencies of compounds 1 and 2 were calculated by density functional method (DFT/B3LYP) using 6-31G (d, p) basis set, bond parameters and IR frequencies were correlated with the experimental data. 1H and 13C chemical shifts of compound 1 and 1H chemical shifts of compound 2 were calculated with GIAO method and correlated with experimental data. Hyperconjugative interactions were studied with the help of natural bond order analysis (NBO). Electronic properties of both the compounds such as HOMO-LUMO energies were measured with the help of time dependent DFT method.

  10. Fischer indolisation of N-(α-ketoacyl)anthranilic acids into 2-(indol-2-carboxamido)benzoic acids and 2-indolyl-3,1-benzoxazin-4-ones and their NMR study.

    PubMed

    Proisl, Karel; Kafka, Stanislav; Urankar, Damijana; Gazvoda, Martin; Kimmel, Roman; Košmrlj, Janez

    2014-12-21

    N-(α-ketoacyl)anthranilic acids reacted with phenylhydrazinium chloride in boiling acetic acid to afford 2-(indol-2-carboxamido)benzoic acids in good to excellent yields and 2-indolyl-3,1-benzoxazin-4-ones as by-products. The formation of the latter products could easily be suppressed by a hydrolytic workup. Alternatively, by increasing the reaction temperature and/or time, 2-indolyl-3,1-benzoxazin-4-ones can be obtained exclusively. Optimisations of the reaction conditions as well as the scope and the course of the transformations were investigated. The products were characterized by (1)H, (13)C and (15)N NMR spectroscopy. The corresponding resonances were assigned on the basis of the standard 1D and gradient selected 2D NMR experiments ((1)H-(1)H gs-COSY, (1)H-(13)C gs-HSQC, (1)H-(13)C gs-HMBC) with (1)H-(15)N gs-HMBC as a practical tool to determine (15)N NMR chemical shifts at the natural abundance level of (15)N isotope.

  11. Three new lignan glycosides with IL-6 inhibitory activity from Akebia quinata.

    PubMed

    Jin, Hong-Guang; Kim, A Ryun; Ko, Hae Ju; Lee, Sang Kook; Woo, Eun-Rhan

    2014-01-01

    Three new lignan glycosides, akeqintoside A [(7S,8S)-7,8-dihydro-8-hydroxymethyl-7-(4-hydroxy-3-methoxyphenyl)-1'-benzofuranpropanol 2'-O-β-D-glucopyranoside] (1), akeqintoside B [(7R,8R)-7,8-dihydro-8-hydroxymethyl-7-(4-hydroxy-3-methoxyphenyl)-1'-(9'-methoxy-7'-propenyl) benzofuran 2'-O-β-D-glucopyranoside] (2), and akequintoside C [7R*,8R*-dihydroxy-7-(4-hydroxy-3-methoxyphenyl)-glycerol 9-O-β-D-(6'-O-caffeoyl)-glucopyranoside] (3) were isolated from Akebia quinata along with five known compounds, syringin (4), vanilloloside (5), salidroside (6), 3,4-dihydroxyphenylethyl alcohol 8-O-β-D-glucopyranoside (7), and calceolarioside B (8). The structures of the compounds were identified based on one dimensional (1D)- and 2D-NMR, including (1)H-(1)H correlation spectroscopy (COSY), heteronuclear single quantum coherence (HSQC), heteronuclear multiple bond connectivity (HMBC) and nuclear Overhauser effect spectroscopy (NOESY) spectroscopic analyses. The inhibitory activity of these isolated compounds against interleukin-6 (IL-6) production in tumor necrosis factor-alpha (TNF-α) stimulated MG-63 cells was also examined.

  12. Identification of endogenous metabolites in human sperm cells using proton nuclear magnetic resonance ((1) H-NMR) spectroscopy and gas chromatography-mass spectrometry (GC-MS).

    PubMed

    Paiva, C; Amaral, A; Rodriguez, M; Canyellas, N; Correig, X; Ballescà, J L; Ramalho-Santos, J; Oliva, R

    2015-05-01

    The objective of this study was to contribute to the first comprehensive metabolomic characterization of the human sperm cell through the application of two untargeted platforms based on proton nuclear magnetic resonance ((1) H-NMR) spectroscopy and gas chromatography coupled to mass spectrometry (GC-MS). Using these two complementary strategies, we were able to identify a total of 69 metabolites, of which 42 were identified using NMR, 27 using GC-MS and 4 by both techniques. The identity of some of these metabolites was further confirmed by two-dimensional (1) H-(1) H homonuclear correlation spectroscopy (COSY) and (1) H-(13) C heteronuclear single-quantum correlation (HSQC) spectroscopy. Most of the metabolites identified are reported here for the first time in mature human spermatozoa. The relationship between the metabolites identified and the previously reported sperm proteome was also explored. Interestingly, overrepresented pathways included not only the metabolism of carbohydrates, but also of lipids and lipoproteins. Of note, a large number of the metabolites identified belonged to the amino acids, peptides and analogues super class. The identification of this initial set of metabolites represents an important first step to further study their function in male gamete physiology and to explore potential reasons for dysfunction in future studies. We also demonstrate that the application of NMR and MS provides complementary results, thus constituting a promising strategy towards the completion of the human sperm cell metabolome.

  13. Hepatoprotective triterpene saponins from the roots of Glycyrrhiza inflata.

    PubMed

    Zheng, Yun-Feng; Wei, Juan-Hua; Fang, Shi-Qi; Tang, Yu-Ping; Cheng, Hai-Bo; Wang, Tian-Lin; Li, Cun-Yu; Peng, Guo-Ping

    2015-04-09

    Two novel oleanane-type triterpene saponins, licorice-saponin P2 (1) and licorice-saponin Q2 (3), together with nine known compounds 2, 4-11, have been isolated from the water extract of the roots of Glycyrrhiza inflata. The structures of these compounds were elucidated on the basis of spectroscopic analysis, including 2D-NMR experiments (1H-1H COSY, HSQC, HMBC and ROESY). In in vitro assays, compounds 2-4, 6 and 11 showed significant hepatoprotective activities by lowering the ALT and AST levels in primary rat hepatocytes injured by D-galactosamine (D-GalN). In addition, compounds 2-4, 6, 7 and 11 were found to inhibit the activity of PLA2 with IC50 values of 6.9 μM, 3.6 μM, 16.9 μM, 27.1 μM, 32.2 μM and 9.3 μM, respectively, which might be involved in the regulation of the hepatoprotective activities observed.

  14. Two novel bioactive glucosinolates from Broccoli (Brassica oleracea L. var. italica) florets.

    PubMed

    Survay, Nazneen Shaik; Kumar, Brajesh; Jang, Mi; Yoon, Do-Young; Jung, Yi-Sook; Yang, Deok-Chun; Park, Se Won

    2012-09-01

    Two novel glucosinolates along with one known glucosinolate were isolated from Broccoli (Brassica oleracea L. var. italica) florets. Their structures were established mainly by 1D ((1)H and (13)C NMR), 2D NMR ((1)H-(1)H COSY, DEPT 135°, HSQC and HMBC), and Tandem MS-MS spectrometric data as 2-mercaptomethyl sulfinyl glucosinolate [(Z)-4-(methylsulfinyl)-N-(sulfooxy)-2-((2'S,3'R,4'S,5'S,6'R)-3',4',5'-trihydroxy-6'(hydroxylmethyl)-2'-mercapto tetrahydro-2H-pyran-2-yl) butane amide] 1, (Z)-1-((2S,5S)-5-hydroxytetra-hydro-2H-pyran-2-ylthio)-2-(1H-indol-3-yl) ethylidene amino sulfate 2 and a known cinnamoyl [6'-O-trans-(4″-hydroxy cinnamoyl)4-(methylsulphinyl)butyl glucosinolate] 3. Compound 1 exhibited scavenging activity against DPPH with an inhibitory concentration IC(50) of 20 mM, whereas compound 3 was a weak antioxidant when compared to the standard quercetin (5 mM) as a positive control. Both the compounds showed a significant and similar antimicrobial activity against Staphylococcus aureus with an IC(50) of <625 μg/mL when compared to antibiotic duricef. Against Salmonella typhimurium the IC(50) of 1 and 3 was determined as <625 μg/mL and <1250 μg/mL, respectively, when compared to ampicillin (IC(50) ≤ 39 μg/mL) as a positive control.

  15. Isolation and structure elucidation of cytotoxic polyacetylenes and polyenes from Echinacea pallida.

    PubMed

    Pellati, Federica; Calò, Samuele; Benvenuti, Stefania; Adinolfi, Barbara; Nieri, Paola; Melegari, Michele

    2006-07-01

    Bioassay-guided fractionation of n-hexane extracts of Echinacea pallida (Asteraceae) roots led to the isolation and structure elucidation of two polyacetylenes (1, 3) and three polyenes (2, 4, 5). Two are known hydroxylated compounds, namely 8-hydroxy-pentadeca-(9E)-ene-11,13-diyn-2-one (1) and 8-hydroxy-pentadeca-(9E,13Z)-dien-11-yn-2-one (2). Two dicarbonylic constituents, namely pentadeca-(9E)-ene-11,13-diyne-2,8-dione (3) and pentadeca-(9E,13Z)-dien-11-yne-2,8-dione (4), were isolated and characterized for the first time. Furthermore, the structure elucidation of pentadeca-(8Z,13Z)-dien-11-yn-2-one (5) is described. The structure of the compounds isolated was determined on the basis of UV, IR, NMR (including 1D and 2D NMR experiments, such as 1H-1H gCOSY, gHSQC-DEPT, gHMBC, gNOESY) and MS spectroscopic data. The cytotoxic activity of the isolated constituents against MIA PaCa-2 human pancreatic adenocarcinoma cells was evaluated in the concentration range 1-100 microg/ml. Results show that the hydroxylated compounds (1, 2) have low cytotoxicity, while the more hydrophobic polyacetylenes (3) and polyenes (4, 5) displayed moderate activity.

  16. Synthesis, characterization, computational calculation and biological studies of some 2,6-diaryl-1-(prop-2-yn-1-yl)piperidin-4-one oxime derivatives

    NASA Astrophysics Data System (ADS)

    Sundararajan, G.; Rajaraman, D.; Srinivasan, T.; Velmurugan, D.; Krishnasamy, K.

    2015-03-01

    A new series of 2,6-diaryl-1-(prop-2-yn-1-yl)piperidin-4-one oximes (17-24) were designed and synthesized from 2,6-diarylpiperidin-4-one oximes (9-16) with propargyl bromide. Unambiguous structural elucidation has been carried out by investigating IR, NMR (1H, 13C, 1H-1H COSY and HSQC), mass spectral techniques and theoretical (DFT) calculations. Further, crystal structure of compound 17 was evaluated by single crystal X-ray diffraction analysis. Single crystal X-ray structural analysis of compound 17 evidenced that the configuration about Cdbnd N double bond is syn to C-5 carbon (E-form). The existence of chair conformation was further confirmed by theoretical DFT calculation. All the synthesized compounds were screened for in vitro antimicrobial activity against a panel of selected bacterial and fungal strains using Ciprofloxacin and Ketoconazole as standards. The minimum inhibition concentration (MIC) results revealed that most of the 2,6-diaryl-1-(prop-2-yn-1-yl)piperidin-4-one oximes (17, 19, 20 and 23) exhibited better activity against the selected bacterial and fungal strains.

  17. Bioactive phenylpropanoid analogues from Piper betle L. var. haldia leaves.

    PubMed

    Atiya, Akhtar; Sinha, Barij Nayan; Lal, Uma Ranjan

    2017-02-15

    Phytochemical analyses of the chloroform extract of Piper betle L. var. birkoli, Piperaceae, leaves led to the isolation of two new phenylpropanoid analogues: bis-chavicol dodecanoyl ester (2) and bis-hydroxychavicol dodecanoyl ester (3), along with one known compound: allyl-3-methoxy-4-hydroxybenzene (1) on the basis of spectroscopic data 1D ((1)H and (13)C) and 2D ((1)H-(1)H COSY and HMBC) NMR, as well as ESI-MS, FT-IR, HR-ESI-MS and LC-ESI-MS. Compound 2 and 3 exhibited excellent antioxidant DPPH radical scavenging activity with IC50 values of 12.67 μg/mL and 1.08 μg/mL compared to ascorbic acid as a standard antioxidant drug with IC50 value of 6.60 μg/mL. Evaluation of cytotoxic activity against two human oral cancer cell lines (AW13516 and AW8507) showed significant effect with GI50 values of 19.61 and 23.01 μg/mL for compound 2 and 10.25 and 13.12 μg/mL for compound 3, compared to Doxorubicin(®) as a standard cytotoxic drug with GI50 value of < 10 μg/mL.

  18. Antioxidant C-glycosylflavones of Drymaria cordata (Linn.) Willd.

    PubMed

    Nono, Raymond N; Nguelefack-Mbuyo, Elvine P; Nzowa, Laurence K; Ponou, Beaudelaire K; Teponno, Rémy B; Nguelefack, Télesphore B; Barboni, Luciano; Tapondjou, Léon A; Park, Hee-Juhn

    2016-01-01

    A new C-glycosylflavone, drymaritin E (6-C-(3-keto-β-digitoxopyranosyl)-4'-O-(β-D-glucopyranosyl)-7-methoxyl-5,4'-dihydroxylflavone) 1 was isolated from the oily upper phase (SU) of the MeOH extract from aerial parts of Drymaria cordata together with two known compounds (cassiaoccidentalin A 2 and anemonin 3) and an inseparable mixture of two known C-glycosylflavones 5,4'-dihydroxy-7-methoxyflavone-6-C-(2''-O-α-L-rhamnopyranosyl)-β-D-glucopyranoside 4a and 5,7,3',4'-tetrahydroxyflavone-6-C-(2''-O-α-L-rhamnopyranosyl)-β-D-glucopyranoside 4b. The alkaline hydrolysis of 3 led to a new hemisynthetic derivative, sodium anemonate (sodium 2-((1'E) 2'-sodium-carboxylate-vinyl)-5-oxo-cyclohex-1-ene carboxylate) 3a. The chemical structures were determined by spectroscopic methods ((1)H NMR, (13)C NMR, (1)H-(1)H COSY, HMBC, HSQC, and NOESY) and mass spectrometry (ESI-MS). C-glycosylflavones had significant free radical-scavenging activities on the radical 2,2-diphenyl-1-picrylhydrazyl (DPPH). However, SU and compounds 3 and 3a exhibited no activity. In particular, compound 1 exhibited a concentration-dependent radical scavenging activity on DPPH with EC50 of 31.43 µg/mL.

  19. Salicin derivatives from Salix glandulosa and their biological activities.

    PubMed

    Kim, Chung Sub; Subedi, Lalita; Park, Kyoung Jin; Kim, Sun Yeou; Choi, Sang Un; Kim, Ki Hyun; Lee, Kang Ro

    2015-10-01

    Two new salicin derivatives, saliglandin (1) and 6'-O-(Z)-p-coumaroylsalicin (2), along with fourteen known analogues (3-16) were isolated from the twigs of Salix glandulosa Seemen. The structures of 1-16 were characterized by the use of NMR methods ((1)H and (13)C NMR, (1)H-(1)H COSY, HSQC and HMBC), chemical hydrolysis, and GC/MS. The full NMR data assignment of the known compounds 6, 13, and 14 are reported for the first time. Isolated compounds were evaluated for their nitric oxide (NO) inhibitory efficacy in lipopolysaccharide (LPS)-activated microglial cell (BV-2). Compounds 2, 5, 8-16 significantly inhibited NO production, compound 11 being the most efficacious (IC50 13.57 μM) respectively. Moreover, compound 16 dramatically increased the nerve growth factor (NGF) production (165.24 ± 11.1%) in C6 glioma cells. Taken together, these results revealed that salicin derivatives from Salix glandulosa might have potent effect as anti-neuroinflammatory agents.

  20. Biotransformation of the antiviral drugs acyclovir and penciclovir in activated sludge treatment.

    PubMed

    Prasse, Carsten; Wagner, Manfred; Schulz, Ralf; Ternes, Thomas A

    2011-04-01

    The biotransformation of the two antiviral drugs, acyclovir (ACV) and penciclovir (PCV), was investigated in contact with activated sludge. Biodegradation kinetics were determined, and transformation products (TPs) were identified using Hybrid Linear Ion Trap- FT Mass Spectrometry (LTQ Orbitrap Velos) and 1D (1H NMR, 13C NMR) and 2D (1H,1H-COSY, 1H-(13)C-HSQC) NMR Spectroscopy. ACV and PCV rapidly dissipated in the activated sludge batch systems with half-lives of 5.3 and 3.4 h and first-order rate constants in relation to the amount of suspended solids (SS) of 4.9±0.1 L gss(-1) d(-1) and 7.6±0.3 L gss(-1) d(-1), respectively. For ACV only a single TP was found, whereas eight TPs were identified for PCV. Structural elucidation of TPs exhibited that transformation only took place at the side chain leaving the guanine moiety unaltered. The oxidation of the primary hydroxyl group in ACV resulted in the formation of carboxy-acyclovir (Carboxy-ACV). For PCV, transformation was more diverse with several enzymatic reactions taking place such as the oxidation of terminal hydroxyl groups and β-oxidation followed by acetate cleavage. Analysis of different environmental samples revealed the presence of Carboxy-ACV in surface and drinking water with concentrations up to 3200 ng L(-1) and 40 ng L(-1), respectively.

  1. Five new alkaloids from Coptidis Rhizoma-Euodiae Fructus couple and their cytotoxic activities against gastrointestinal cancer cells.

    PubMed

    Qian, Ping; Yang, Xiu-Wei

    2014-03-01

    A new indoloquinazoline alkaloid, 10-methoxywuchuyuamide I (1), three new benzylisoquinoline alkaloids, named as coptichic aldehyde (2), coptichine (3) and 13-carboxaldehyde-8-oxocoptisine (4), and a new isoindoline alkaloid, named as coptichinamide (5), together with two known alkaloids, wuchuyuamide I (6) and 8-oxocoptisine (7) were isolated from the Coptidis Rhizoma-Euodiae Fructus couple. Their chemical structures were determined by extensive spectroscopic analyses, including IR, UV, EI-MS, HRESI-MS, 1D and 2D NMR data ((1)H NMR, (13)C NMR, (1)H-(1)H COSY, HSQC and HMBC). Cytotoxicities of the isolated alkaloids against NCI-N87 and Caco-2 cell lines were evaluated. Four benzylisoquinoline alkaloids 2-4 and 7 showed inhibitory activities against NCI-N87 cell with IC50 values range from 8.92 to 35.98 μM. The alkaloid 3 was a new antiproliferation compound against NCI-N87 cells. The results provided valuable information for further investigation of alkaloid 3 as a chemopreventive agent.

  2. Triterpene saponins from Cyclamen trocopteranthum.

    PubMed

    Mihci-Gaidi, Ghezala; Ozbey, Suheyla; Orhan, Ilkay; Sener, Bilge; Miyamoto, Tomofumi; Mirjolet, Jean-François; Duchamp, Olivier; Mitaine-Offer, Anne-Claire; Lacaille-Dubois, Marie-Aleth

    2010-05-01

    Two new triterpene saponins ( 1- 2) together with three known saponins, deglucocyclamin I ( 3), cyclamin ( 4), and mirabilin ( 5), were isolated from the tubers of Cyclamen trocopteranthum. They were elucidated as 3 beta- O-{4- O-[3-hydroxyl-3-methylglutaryl]- beta-D-xylopyranosyl-(1 --> 2)- beta-D-glucopyranosyl-(1 --> 4)-[ beta-D-glucopyranosyl-(1 --> 2)]- alpha-L-arabinopyranosyl}-16 alpha-hydroxy-13 beta,28-epoxy-oleanan-30-al ( 1) and 3 beta- O-{4- O-[3-hydroxyl-3-methylglutaryl]- beta-D-xylopyranosyl-(1 --> 2)-[ beta-D-glucopyranosyl-(1 --> 6)]- beta-D-glucopyranosyl-(1 --> 4)-[ beta-D-glucopyranosyl-(1 --> 2)]- alpha-L-arabinopyranosyl}-16 alpha-hydroxy-20,30-lactone-olean-12-ene ( 2). Their structures were characterized mainly by a combination of 1D- and 2D-NMR techniques ( (1)H- (1)H COSY, TOCSY, NOESY, HSQC, and HMBC) and mass spectroscopy. Saponins 1, 3, and 4 showed a weak cytotoxic activity when tested against HT-29 and HCT 116 tumor colon cancer cells. Georg Thieme Verlag KG Stuttgart New York.

  3. Synthesis and characterization of chitosan alkyl urea.

    PubMed

    Wang, Jing; Jiang, Ji-Zhou; Chen, Wei; Bai, Zheng-Wu

    2016-07-10

    Chitosan is a versatile material employed for various purposes in many fields including the development of chiral stationary phases for enantioseparation. Chitosan alkyl urea is a kind of intermediate used to prepare enantioseparation materials. In order to synthesize the intermediates, in the present work, a new way to prepare chitosan alkyl urea has been established: chitosan was first reacted with methyl chloroformate yielding N-methoxyformylated chitosan, which was then converted to chitosan alkyl urea through amine-ester exchange reaction. With a large excess of methyl chloroformate and primary amine of low stereohindrance, the amino group in chitosan could be almost completely converted to ureido group. The as-prepared chitosan alkyl urea derivatives were characterized by IR, (1)H NMR, (13)C NMR,(1)H-(1)H COSY and (1)H-(13)C HSQC NMR spectra. The chemical shifts of hydrogen and carbon atoms of glucose unit were assigned. It was found that the degree of substitution was obviously lower if cyclopropyl amine, aniline, tert-butyl amine and diethyl amine were used as reactants for the amine-ester exchange reaction. The reason was explained with the aid of theoretical calculations. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. In vivo and in vitro NMR spectroscopy reveal a putative novel inborn error involving polyol metabolism.

    PubMed

    Moolenaar, S H; van der Knaap, M S; Engelke, U F; Pouwels, P J; Janssen-Zijlstra, F S; Verhoeven, N M; Jakobs, C; Wevers, R A

    2001-05-01

    In vivo NMR spectroscopy was performed on the brain of a patient with a leukoencephalopathy, revealing unknown resonances between 3.5 and 4.0 ppm. In addition, urine and CSF of the patient were measured using high-resolution NMR spectroscopy. Also in these in vitro spectra, unknown resonances were observed in the 3.5-4.0 ppm region. Homonuclear (1)H two-dimensional J-resolved spectroscopy (JRES) and (1)H-(1)H correlation spectroscopy (COSY) were performed on the patient's urine for more accurate assignment of resonances. The NMR spectroscopic studies showed that the unknown resonances could be assigned to arabinitol and ribitol. This was confirmed using gas chromatography. The arabinitol was identified as D-arabinitol. The patient is likely to suffer from an as yet unknown inborn error of metabolism affecting D-arabinitol and ribitol metabolism. The primary molecular defect has not been found yet. Urine spectra of patients suffering from diabetes mellitus or galactosemia were recorded for comparison. Resonances outside the 3.2-4.0 ppm region, which are the most easy to recognize in body fluid spectra, allow easy recognition of various sugars and polyols. The paper shows that NMR spectroscopy in body fluids may help identifying unknown resonances observed in in vivo NMR spectra. Copyright 2001 John Wiley & Sons, Ltd.

  5. A definitive analytical spectroscopic study of Indian yellow, an ancient pigment used for dating purposes.

    PubMed

    de Faria, Dalva L A; Edwards, Howell G M; Careaga, Valeria; Walt, Nicholas; Maier, Marta S

    2017-02-01

    The Raman spectrum of tartrazine has been mistakenly reported as being that of Indian yellow in the literature, which has serious consequences for the identification of this pigment in art works regarding their authentication. Unlike tartrazine, Indian yellow (a natural mixture of the magnesium and calcium salts of euxanthic acid) exhibits in its Raman spectrum a strong fluorescent background when visible excitation is used, however, excitation in the near infrared (1064nm) permitted the observation of the Raman bands from the raw pigment with the main features placed at 1346, 1368, 1425, 1441 and 1626cm(-1). Indian yellow identification was assured by (1)H and (13)C Nuclear Magnetic Resonance characterization and the complete assignment of the proton and carbon resonances was accomplished using heteronuclear single quantum correlation (HSQC), heteronuclear multiple bond correlation (HMBC), nuclear overhauser effect spectroscopy (NOESY) and (1)H-(1)H correlation spectroscopy (COSY). Scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and X-ray fluorescence (XRF) analyzes were also conducted on a genuine sample of this historical pigment.

  6. Isoorientin, a Selective Inhibitor of Cyclooxygenase-2 (COX-2) from the Tubers of Pueraria tuberosa.

    PubMed

    Sumalatha, Manne; Munikishore, Rachakunta; Rammohan, Aluru; Gunasekar, Duvvuru; Kumar, Kotha Anil; Reddy, Kakularam Kumar; Azad, Rajaram; Reddanna, Pallu; Bodo, Bernard

    2015-10-01

    Bioassay-guided fraction of the methanol extract of the roots of Pueraria tuberose DC yielded puerarin, an isoflavone C-glycoside (PT-1), isoorientin, a flavone C-glycoside (PT-2) and mangiferin, a xanthone C-glycoside (PT-3). The extracts and the isolated compounds were screened for potent anti-inflammatory components inhibiting the cyclooxygenases (COX-1 and COX-2) and 5-lipoxygenase (5-LOX), the target enzymes of inflammation, by employing spectroscopic/polorographic methods. Among these, isoorientin was found to be a potent inhibitor of COX-2with an IC50 value of 39 μM. Docking studies were carried out to understand the interactions of isorientin (PT-2) with COX-2.The structures of the isolates were determined by mass spectrometry and 2D-NMR techniques including HSQC, HMBC, NOESY and 1H-1H COSY experiments. Although isoorientin and mangiferin have been reported from several plant sources, this is the first report of their isolation from a Pueraria species.

  7. Antimicrobial activity of Calotropis procera Ait. (Asclepiadaceae) and isolation of four flavonoid glycosides as the active constituents.

    PubMed

    Nenaah, Gomah

    2013-07-01

    Antimicrobial activity of solvent extracts and flavonoids of Calotropis procera growing wild in Saudi Arabia was evaluated using the agar well-diffusion method. A bioassay-guided fractionation of the crude flavonoid fraction (Cf3) of MeOH extract which showed the highest antimicrobial activity led to the isolation of four flavonoid glycosides as the bioactive constituents. Structure of compounds have been elucidated using physical and spectroscopic methods including (UV, IR, (1)H, (13)C-NMR, DEPT, 2D (1)H-(1)H COSY, HSQC, HMBC and NOESY). Compounds were found to be the 3-O-rutinosides of quercetin, kaempferol and isorhamnetin, besides the flavonoid 5-hydroxy-3,7-dimethoxyflavone-4'-O-β-glucopyranoside. Most of the isolated extracts showed antimicrobial activity against the test microorganisms, where the crude flavonoid fraction was the most active, diameter of inhibition zones ranged between 15.5 and 28.5 mm against the tested bacterial strains, while reached 30 mm against the fungal Candida albicans. The minimal inhibitory concentrations varied from 0.04 to 0.32 mg/ml against all of the tested microorganisms in case of the crude flavonoid fraction. Quercetin-3-O-rutinoside showed superior activity over the remainder flavonoids. The Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis) were more susceptible than the Gram-negative (Pseudomonas aeruginosa and Salmonella enteritidis) and the yeast species were more susceptible than the filamentous fungi. The study recommend the use of such natural products as antimicrobial biorationals.

  8. [Two new furostanol saponins from the rhizomes of Anemarrhena asphodeloides].

    PubMed

    Kang, Li-Ping; Ma, Bai-Ping; Shi, Tian-Jun; Zhang, Jie; Xiong, Cheng-Qi

    2006-06-01

    To investigate the chemical constituents of the rhizomes of Anemarrhena asphodeloides Bunge. The compounds were separated by means of solvent extraction, chromatography on absorbent resin SP825 and silica gel C18 repeatedly, and their structures were elucidated on the basis of chemical methods and spectral analyses (FAB-MS, 1H NMR, 13C NMR, 1H-1H COSY). Six steroidal saponins were isolated from the rhizomes of Anemarrhena asphodeloides Bunge. They were identified as (25S)-26-O-beta-D-glucopyranosyl-22-hydroxy-5beta-furostane-2beta, 3beta, 26-triol-3-O-beta-D-glucopyranosyl-(1 --> 2)-beta-D-galactopyranoside (timosaponin N, 1), timosaponin E1 (2), (25S)-26-O-beta-D-glucopyranosyl-22-methoxy-5beta-furostane-2beta, 3beta, 26-triol-3-O-beta-D-glucopyranosyl-(1 --> 2)-beta-D-galactopyranoside (timosaponin O, 3) , timosaponin E2 (4), (25R) -26-O-beta-D-glucopyranosyl-22-hydroxy-5alpha-furostane-2alpha, 3beta, 26-triol-3-O-beta-D-glucopyranosyl-(1 --> 2)-[beta-D-xylpyranosyl-(1 --> 3)]-beta-D-glucopyranosyl-(1 --> 4)-beta-D-galactopyranoside (purpureagitosid, 5) and marcogenin-3-O-beta-D-glucopyranosyl-(1 --> 2)-beta-D-galactopyranoside (6). Compound 1 and compound 3 are new compounds, and compound 5 was isolated from the rhizomes of Anemarrhena asphodeloides Bunge for the first time.

  9. Triterpene saponins from barrel medic (Medicago truncatula) aerial parts.

    PubMed

    Kapusta, Ireneusz; Stochmal, Anna; Perrone, Angela; Piacente, Sonia; Pizza, Cosimo; Oleszek, Wieslaw

    2005-03-23

    Triterpene saponins from Medicago truncatula aerial parts have been separated and their structures determined by the extensive use of 1D- and 2D-NMR experiments including 1H-1H (DQF-COSY, 1D-TOCSY) and 1H-13C (HSQC, HMBC) spectroscopy along with ESIMS. Fifteen individual compounds were isolated that included seven medicagenic acid and eight zanhic acid glycosides. Additionally, two soyasapogenol B and soyasapogenol E glycosides were identified by MS/MS and TLC. Four medicagenic acid glycosides (5, 11, 12, 14) and eight zanhic acid glycosides (1-4, 6-9) are reported here for the first time. The common feature of M. truncatula aerial part saponins is the (1-->3) linkage between the two glucose units at C-3 of medicagenic and zanhic acids, which is different from that found in alfalfa (Medicago sativa), where this linkage was always (1-->2). This may suggest differences in glucosyltransferases between these two Medicago species.

  10. Identification of diterpene alkaloids from Aconitum napellus subsp. firmum and GIRK channel activities of some Aconitum alkaloids.

    PubMed

    Kiss, Tivadar; Orvos, Péter; Bánsághi, Száva; Forgo, Peter; Jedlinszki, Nikoletta; Tálosi, László; Hohmann, Judit; Csupor, Dezső

    2013-10-01

    Diterpene alkaloids neoline (1), napelline (2), isotalatizidine (3), karakoline (4), senbusine A (5), senbusine C (6), aconitine (7) and taurenine (8) were identified from Aconitum napellus L. subsp. firmum, four (2-4, 6) of which are reported for the first time from this plant. The structures were determined by means of LC-MS, 1D and 2D NMR spectroscopy, including (1)H-(1)H COSY, NOESY, HSQC and HMBC experiments. Electrophysiological effects of the isolated compounds, together with nine diterpene alkaloids previously obtained from Aconitum toxicum and Consolida orientalis were investigated on stable transfected HEK-hERG (Kv11.1) and HEK-GIRK1/4 (Kir3.1 and Kir3.4) cell lines using automated patch clamp equipment. Significant blocking activity on GIRK channel was exerted by aconitine (7) (45% at 10 μM), but no blocking activities of the other investigated compounds were detected. The tested compounds were inactive on hERG channel in the tested concentration. The comparison of the previously reported metabolites of A. napellus subsp. firmum and compounds identified in our experiment reveals substantial variability of the alkaloid profile of this taxon.

  11. Hyphenating Centrifugal Partition Chromatography with Nuclear Magnetic Resonance through Automated Solid Phase Extraction.

    PubMed

    Bisson, Jonathan; Brunel, Marion; Badoc, Alain; Da Costa, Grégory; Richard, Tristan; Mérillon, Jean-Michel; Waffo-Téguo, Pierre

    2016-10-18

    Centrifugal partition chromatography (CPC) and all countercurrent separation apparatus provide chemists with efficient ways to work with complex matrixes, especially in the domain of natural products. However, despite the great advances provided by these techniques, more efficient ways of analyzing the output flow would bring further enhancement. This study describe a hyphenated approach made by coupling NMR with CPC through a hybrid-indirect coupling made possible by using a solid phase extraction (SPE) apparatus intended for high-pressure liquid chromatography (HPLC)-NMR hyphenation. Some hardware changes were needed to adapt the incompatible flow-rates and a reverse-engineering approach that led to the specific software required to control the apparatus. 1D (1)HNMR and (1)H-(1)H correlation spectroscopy (COSY) spectra were acquired in reasonable time without the need for any solvent-suppression method thanks to the SPE nitrogen drying step. The reduced usage of expensive deuterated solvents from several hundreds of milliliters to the milliliter order is the major improvement of this approach compared to the previously published ones.

  12. The NMR studies on two new furostanol saponins from Agave sisalana leaves.

    PubMed

    Zou, Peng; Fu, Jing; Yu, He-shui; Zhang, Jie; Kang, Li-ping; Ma, Bai-ping; Yan, Xian-zhong

    2006-12-01

    The detailed NMR studies and full assignments of the 1H and 13C spectral data for two new furostanol saponins isolated from Agave sisalana leaves are described. Their structures were established using a combination of 1D and 2D NMR techniques including 1H, 13C, 1H-1H COSY, TOCSY, HSQC, HMBC and HSQC-TOCSY, and also FAB-MS spectrometry and chemical methods. The structures were established as (25S)-26-(beta-D-glucopyranosyl)-22 xi-hydroxyfurost-12-one-3beta-yl-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->3)-O-[O-beta-D-glucopyranosyl-(1-->2)]-O-beta-D-glucopyranosyl-(1-->4)-beta-D-galacto- pyranoside (1) and (25S)-26-(beta-D-glucopyranosyl)-22xi-hydroxyfurost-5-en-12-one-3beta-yl-O-alpha-L-rhamno- pyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->3)-O-[O-beta-D-glucopyranosyl-(1-->2)]-O-beta-D-glucopyranosyl- (1-->4)-beta-D-galactopyranoside (2).

  13. New Sweet-Tasting C21-Pregnane Glycosides from Pericarps of Myriopteron extensum.

    PubMed

    Sun, Guo; Dai, Qin; Zhang, Hong-Xia; Li, Zhi-Jian; Du, Zhi-Zhi

    2016-12-14

    Ten novel C21 pregnane glycosides, extensumside C-L (1-10), were isolated as highly sweet-tasting substances from the edible pericarps of Myriopteron extensum (Wight) K. Schum by sensory-guided fractionation and purification. Their structures were determined through 1D and 2D NMR, such as HSQC, HMBC, (1)H-(1)H COSY, HSQC-TOCSY, and ROESY, as well as other spectroscopic analysis combined with chemical evidence. These compounds shared the same aglycone, 3β,16α-dihydroxy-pregn-5-en-20-one, and contained the deoxysugar chain and the glucose chain which were linked to C-3 and C-16 of the aglycone, respectively. The sweetness potency was evaluated by a human sensory panel test and preliminary structure-taste relationship was discussed. The sweetness intensities of these compounds are between 50 and 400 times greater than that of sucrose. Furthermore, quantitation analyses of compounds 1, 3, 4, and 6 in different parts of M. extensum indicated that the concentrations of these sweet components in the pericarps are obviously higher than those in stems and roots.

  14. Steroid glycosides from the starfish Pentaceraster gracilis.

    PubMed

    Vien, Le Thi; Ngoan, Bui Thi; Hanh, Tran Thi Hong; Vinh, Le Ba; Thung, Do Cong; Thao, Do Thi; Thanh, Nguyen Van; Cuong, Nguyen Xuan; Nam, Nguyen Hoai; Kiem, Phan Van; Minh, Chau Van

    2017-05-01

    Using combined chromatographic separations, two new steroid glycosides namely pentacerosides A (1) and B (2), and four known compounds were isolated from the methanol extract of the starfish Pentaceraster gracilis. Their structures were determined on the basis of spectroscopic data ((1)H and (13)C NMR, HSQC, HMBC, (1)H-(1)H COSY, ROESY, and FT-ICR-MS) and by comparing obtained results to the literature values. Among the isolated compounds, only maculatoside (5) showed significant cytotoxic effect against Hep-G2 (IC50 = 16.75 ± 0.69 μM) and SK-Mel2 (IC50 = 19.44 ± 1.45 μM) cell lines and moderate effect on KB (IC50 = 36.53 ± 0.78 μM), LNCaP (IC50 = 39.75 ± 3.34 μM), and MCF7 (IC50 = 47.34 ± 7.01 μM) cell lines.

  15. Synthesis of 21,23-selenium- and tellurium-substituted 5-porphomethenes, 5,10-porphodimethenes, 5,15-porphodimethenes, and porphotrimethenes and their interactions with mercury.

    PubMed

    Ahmad, Sohail; Yadav, Kumar Karitkey; Bhattacharya, Soumee; Chauhan, Prashant; Chauhan, S M S

    2015-04-17

    The 3+1 condensation of symmetrical 16-Selena/telluratripyrranes with symmetrical selenophene-2,5-diols/tellurophene-2,5-diols in the presence of BF3-etheratre or BF3-methanol followed by oxidation with DDQ gave 5,10-porphodimethenes, whereas the process with unsymmetrical selenophene-2,5-diols/tellurophene-2,5-diols gave 5-porphomethenes. In addition, the reaction of unsymmetrical 16-Selena/telluratripyrranes with symmetrical selenophene-2,5-diols/tellurophene-2,5-diols gave the corresponding porphotrimethenes, whereas the process with unsymmetrical selenophene-2,5-diols/tellurophene-2,5-diols gave the 5,15-porphodimethenes. The structures of different products were characterized by IR, (1)H and (13)C NMR, (1)H-(1)H COSY, CHN analysis, and mass spectrometry. The binding of mercury with the calix[4]phyrins mentioned above had been observed in the decreasing order of porphodimethenes > porphomethenes > porphotrimethenes by UV-vis and (1)H NMR spectroscopy.

  16. The effect of substituent, degree of acetylation and positioning of the cationic charge on the antibacterial activity of quaternary chitosan derivatives.

    PubMed

    Sahariah, Priyanka; Gaware, Vivek S; Lieder, Ramona; Jónsdóttir, Sigríður; Hjálmarsdóttir, Martha Á; Sigurjonsson, Olafur E; Másson, Már

    2014-08-21

    A series of water-soluble cationic chitosan derivatives were prepared by chemoselective functionalization at the amino group of five different parent chitosans having varying degrees of acetylation and molecular weight. The quaternary moieties were introduced at different alkyl spacer lengths from the polymer backbone (C-0, C-2 and C-6) with the aid of 3,6-di-O-tert-butyldimethylsilyl protection of the chitosan backbone, thus allowing full (100%) substitution of the free amino groups. All of the derivatives were characterized using 1H-NMR, 1H-1H COSY and FT-IR spectroscopy, while molecular weight was determined by GPC. Antibacterial activity was investigated against Gram positive S. aureus and Gram negative E. coli. The relationship between structure and activity/toxicity was defined, considering the effect of the cationic group's structure and its distance from the polymer backbone, as well as the degree of acetylation within a molecular weight range of 7-23 kDa for the final compounds. The N,N,N-trimethyl chitosan with 100% quaternization showed the highest antibacterial activity with moderate cytotoxicity, while increasing the spacer length reduced the activity. Trimethylammoniumyl quaternary ammonium moieties contributed more to activity than 1-pyridiniumyl moieties. In general, no trend in the antibacterial activity of the compounds with increasing molecular weight or degree of acetylation up to 34% was observed.

  17. A new indole glycoside from the seeds of Raphanus sativus.

    PubMed

    Jin, Hong-Guang; Ko, Hae Ju; Chowdhury, Md Anisuzzaman; Lee, Dong-Sung; Woo, Eun-Rhan

    2016-06-01

    A new indole glycoside, β-D-glucopyranosyl 2-(methylthio)-1H-indole-3-carboxylate, named raphanuside A (1), as well as eight known compounds, β-D-fructofuranosyl-(2 → 1)-(6-O-sinapoyl)-α-D-glucopyranoside (2), (3-O-sinapoyl)-β-D-fructofuranosyl-(2 → 1)-α-D-glucopyranoside (3), (3-O-sinapoyl)-β-D-fructofuranosyl-(2 → 1)-(6-O-sinapoyl)-α-D-glucopyranoside (4), (3,4-O-disinapoyl)-β-D-fructofuranosyl-(2 → 1)-(6-O-sinapoyl)-α-D-glucopyranoside (5), isorhamnetin 3,4'-di-O-β-D-glucoside (6), isorhamnetin 3-O-β-D-glucoside-7-O-α-L-rhamnoside (7), isorhamnetin 3-O-β-D-glucoside (8) and 3'-O-methyl-(-)-epicatechin 7-O-β-D-glucoside (9) were isolated from the seeds of Raphanus sativus. Furthermore, compounds 1-3 and 6-9, were isolated from this plant for the first time. The structures of compounds 1-9 were identified using 1D and 2D NMR, including (1)H-(1)H COSY, HSQC, HMBC and NOESY spectroscopic analyses. The inhibitory activity of these isolated compounds against interleukin-6 (IL-6) production in TNF-α stimulated MG-63 cells was also examined.

  18. A new α-glucosidase inhibitor from Achillea fragrantissima (Forssk.) Sch. Bip. growing in Egypt.

    PubMed

    Ezzat, Shahira M; Salama, Maha M

    2014-01-01

    α-Glucosidase inhibitors (AGIs) represent a class of oral antidiabetic drugs that delay the absorption of ingested carbohydrates, reducing the postprandial glucose and insulin peaks to reach normoglycaemia. In this study, a bioassay-guided fractionation of the ethanolic extract of the aerial parts of Achillea fragrantissima (Forssk.) Sch. Bip. growing in Egypt led to the isolation of a new potent AGI; acacetin-6-C-(6″-acetyl-β-D-glucopyranoside)-8-C-α-L-arabinopyranoside (5) alongside with four known compounds: chondrillasterol (1), quercetin-3,6,7-trimethyl ether (chrysosplenol-D) (2), isovitexin-4'-methyl ether (3) and isovitexin (4). The structure of the new compound (5) was elucidated on the basis of its spectral data, including HR-FAB-MS, UV, (1)H NMR, (13)C NMR, (1)H-(1)H COSY, HSQC and HMBC. The new compound (5) exhibited the most significant α-glucosidase inhibitory activity (IC₅₀ 1.5 ± 0.09 μg/mL). Under the assay conditions, all the tested compounds were more potent than the positive control acarbose (IC50 224 ± 2.31 μg/mL).

  19. Ruthenium(II) bipyridine complexes bearing new keto-enol azoimine ligands: Synthesis, structure, electrochemistry and DFT calculations

    NASA Astrophysics Data System (ADS)

    Al-Noaimi, Mousa; Awwadi, Firas F.; Mansi, Ahmad; Abdel-Rahman, Obadah S.; Hammoudeh, Ayman; Warad, Ismail

    2015-01-01

    The novel azoimine ligand, Phsbnd NHsbnd Ndbnd C(COCH3)sbnd NHPh(Ctbnd CH) (H2L), was synthesized and its molecular structure was determined by X-ray crystallography. Catalytic hydration of the terminal acetylene of H2L in the presence of RuCl3·3H2O in ethanol at reflux temperature yielded a ketone (L1 = Phsbnd Ndbnd Nsbnd C(COCH3)dbnd Nsbnd Ph(COCH3) and an enol (L2 = Phsbnd Ndbnd Nsbnd C(COCH3)dbnd Nsbnd PhC(OH)dbnd CH2) by Markovnikov addition of water. Two mixed-ligand ruthenium complexes having general formula, trans-[Ru(bpy)(Y)Cl2] (1-2) (where Y = L1 (1) and Y = L2 (2), bpy is 2.2‧-bipyrdine) were achieved by the stepwise addition of equimolar amounts of (H2L) and bpy ligands to RuCl3·3H2O in absolute ethanol. Theses complexes were characterized by elemental analyses and spectroscopic (IR, UV-Vis, and NMR (1D 1H NMR, 13C NMR, (DEPT-135), (DEPT-90), 2D 1H-1H and 13C-1H correlation (HMQC) spectroscopy)). The two complexes exhibit a quasi-reversible one electron Ru(II)/Ru(III) oxidation couple at 604 mV vs. ferrocene/ferrocenium (Cp2Fe0/+) couple along with one electron ligand reduction at -1010 mV. The crystal structure of complex 1 showed that the bidentate ligand L1 coordinates to Ru(II) by the azo- and imine-nitrogen donor atoms. The complex adopts a distorted trans octahedral coordination geometry of chloride ligands. The electronic spectra of 1 and 1+ in dichloromethane have been modeled by time-dependent density functional theory (TD-DFT).

  20. Ruthenium(II) bipyridine complexes bearing new keto-enol azoimine ligands: synthesis, structure, electrochemistry and DFT calculations.

    PubMed

    Al-Noaimi, Mousa; Awwadi, Firas F; Mansi, Ahmad; Abdel-Rahman, Obadah S; Hammoudeh, Ayman; Warad, Ismail

    2015-01-25

    The novel azoimine ligand, Ph-NH-N=C(COCH3)-NHPh(C≡CH) (H2L), was synthesized and its molecular structure was determined by X-ray crystallography. Catalytic hydration of the terminal acetylene of H2L in the presence of RuCl3·3H2O in ethanol at reflux temperature yielded a ketone (L1=Ph-N=N-C(COCH3)=N-Ph(COCH3) and an enol (L2=Ph-N=N-C(COCH3)=N-PhC(OH)=CH2) by Markovnikov addition of water. Two mixed-ligand ruthenium complexes having general formula, trans-[Ru(bpy)(Y)Cl2] (1-2) (where Y=L1 (1) and Y=L2 (2), bpy is 2.2'-bipyrdine) were achieved by the stepwise addition of equimolar amounts of (H2L) and bpy ligands to RuCl3·3H2O in absolute ethanol. Theses complexes were characterized by elemental analyses and spectroscopic (IR, UV-Vis, and NMR (1D (1)H NMR, (13)C NMR, (DEPT-135), (DEPT-90), 2D (1)H-(1)H and (13)C-(1)H correlation (HMQC) spectroscopy)). The two complexes exhibit a quasi-reversible one electron Ru(II)/Ru(III) oxidation couple at 604 mV vs. ferrocene/ferrocenium (Cp2Fe(0/+)) couple along with one electron ligand reduction at -1010 mV. The crystal structure of complex 1 showed that the bidentate ligand L1 coordinates to Ru(II) by the azo- and imine-nitrogen donor atoms. The complex adopts a distorted trans octahedral coordination geometry of chloride ligands. The electronic spectra of 1 and 1+ in dichloromethane have been modeled by time-dependent density functional theory (TD-DFT). Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Synthesis, spectroscopic characterization, photochemical and photophysical properties and biological activities of ruthenium complexes with mono- and bi-dentate histamine ligand.

    PubMed

    Cardoso, Carolina R; de Aguiar, Inara; Camilo, Mariana R; Lima, Márcia V S; Ito, Amando S; Baptista, Maurício S; Pavani, Christiane; Venâncio, Tiago; Carlos, Rose M

    2012-06-14

    The monodentate cis-[Ru(phen)(2)(hist)(2)](2+)1R and the bidentate cis-[Ru(phen)(2)(hist)](2+)2A complexes were prepared and characterized using spectroscopic ((1)H, ((1)H-(1)H)COSY and ((1)H-(13)C)HSQC NMR, UV-vis, luminescence) techniques. The complexes presented absorption and emission in the visible region, as well as a tri-exponential emission decay. The complexes are soluble in aqueous and non-aqueous solution with solubility in a buffer solution of pH 7.4 of 1.14 × 10(-3) mol L(-1) for (1R + 2A) and 6.43 × 10(-4) mol L(-1) for 2A and lipophilicity measured in an aqueous-octanol solution of -1.14 and -0.96, respectively. Photolysis in the visible region in CH(3)CN converted the starting complexes into cis-[Ru(phen)(2)(CH(3)CN)(2)](2+). Histamine photorelease was also observed in pure water and in the presence of BSA (1.0 × 10(-6) mol L(-1)). The bidentate coordination of the histamine to the ruthenium center in relation to the monodentate coordination increased the photosubstitution quantum yield by a factor of 3. Pharmacological studies showed that the complexes present a moderate inhibition of AChE with an IC(50) of 21 μmol L(-1) (referred to risvagtini, IC(50) 181 μmol L(-1) and galantamine IC(50) 0.006 μmol L(-1)) with no appreciable cytotoxicity toward to the HeLa cells (50% cell viability at 925 μmol L(-1)). Cell uptake of the complexes into HeLa cells was detected by fluorescence confocal microscopy. Overall, the observation of a luminescent complex that penetrates the cell wall and has low cytotoxicity, but is reactive photochemically, releasing histamine when irradiated with visible light, are interesting features for application of these complexes as phototherapeutic agents.

  2. Nine phenylethanoid glycosides from Magnolia officinalis var. biloba fruits and their protective effects against free radical-induced oxidative damage

    PubMed Central

    Ge, Lanlan; Zhang, Wenhui; Zhou, Gao; Ma, Bingxin; Mo, Qigui; Chen, Yuxin; Wang, Youwei

    2017-01-01

    To systematically study the chemical constituents in Magnolia officinalis var. biloba fruits, nine phenylethanoid glycosides were isolated by solvent extraction, silica gel, and preparative high-performance liquid chromatography (HPLC). Their structures were elucidated by 1D and 2D NMR analyses, including COSY, HMQC and HMBC correlations, and HPLC analysis of sugar residue. Nine phenylethanoid glycosides, namely, magnoloside Ia (1), magnoloside Ic (2), crassifolioside (3), magnoloside Ib (4), magnoloside IIIa (5), magnoloside IVa (6), magnoloside IIa (7), magnoloside IIb (8) and magnoloside Va (9), were first isolated from the n-butanol fraction of Magnolia officinalis var. biloba fruits alcohol extract. Free radical scavenging activities of the nine phenylethanoid glycosides were assessed using the DPPH, ABTS, and superoxide anion radical scavenging assays. Simultaneously, protective effects of all compounds against free radical-induced oxidative damage were evaluated by two different kinds of mitochondrial damage model. The protective effects were assessed by mitochondrial swelling, the formations of malondialdehyde (MDA) and lipid hydroperoxide (LOOH), the activities of catalase (CAT), glutathione reductase (GR) and superoxide dismutase (SOD). All phenylethanoid glycosides showed significant protective effects. PMID:28349971

  3. New constituents from noni (Morinda citrifolia) fruit juice.

    PubMed

    Samoylenko, Volodymyr; Zhao, Jianping; Dunbar, D Chuck; Khan, Ikhlas A; Rushing, James W; Muhammad, Ilias

    2006-08-23

    Morinda citrifolia L. (Rubiaceae), known as noni, has a long history of traditional use in the Hawaiian and Tahitian islands. More recently, an array of commercial noni fruit juice products are gaining popularity as dietary supplements, with claims of anticancer and immunostimulant activities. The biologically active principles of noni are not fully known. In continuation of work on the isolation of markers from dietary supplements, this paper reports the isolation of three new markers, namely, 1-O-(3'-methylbut-3'-enyl)-beta-D-glucopyranose (1), 1-n-butyl-4-(5'-formyl-2'-furanyl)methyl succinate (2), and 4-epi-borreriagenin (3), together with the known iridoid glycosides asperulosidic acid (4) and deacetylasperulosidic acid (5) and a mixture of 1-n-butyl-4-methyl-2-hydroxysuccinate (6a) and 1-n-butyl-4-methyl-3-hydroxysuccinate (6b), as well as a mixture of alpha- and beta-glucopyranose from noni fruit juice obtained from Puerto Rico. The structures of compounds were based on 1H and 13C NMR, mainly 2D NMR COSY, HMQC, HMBC, and NOESY experiments, and HRMS. Furthermore, samples from fresh-squeezed noni fruit juice from Japan revealed the presence of scopoletin (7), in addition to compounds 1-6, indicating no significant differences in the marker constituents of noni collected from Atlantic and Pacific regions.

  4. Selective O-Alkylation of the Crown Conformer of Tetra(4-hydroxyphenyl)calix[4]resorcinarene to the Corresponding Tetraalkyl Ether.

    PubMed

    Castillo-Aguirre, Alver; Rivera-Monroy, Zuly; Maldonado, Mauricio

    2017-10-04

    Reactions of glycidyl methacrylate with the crown and chair conformers of tetra(4-hydroxyphenyl)calix[4]resorcinarene were studied. The reactions were done over epoxide groups present in the ester, which can easily undergo an opening reaction with hydroxyl groups in the macrocyclic system. Initially, epoxidation reactions were carried out with pure conformers, and it was observed that the reaction between tetra(4-hydroxyphenyl)calix[4]resorcinarene fixed in the chair conformation does not occur, while for the molecule fixed in the crown conformation only one tetraalkylated derivative was obtained. The obtained product was characterized using IR, ¹H-NMR, (13)C-NMR, COSY, HMQC and HMBC techniques. An exhaustive NMR study showed that the reaction is selective at the hydroxyl groups in the lower rim, without affecting the hydroxyl groups in the upper rim. In addition, the RP-HPLC analysis of the epoxidation reaction mixture, using both crown and chair conformers, showed that only the crown conformer reacted under tested conditions. Finally, a comparative study of the reactivity of tetranonylcalix[4]resorcinarene with glycidyl methacrylate showed that the reaction does not take place. Instead, the formation of the tetranonylcalix[4]resorcinarene tetrasodium salt was observed, which confirms that the hydroxyl groups in the upper rim are unreactive under these conditions.

  5. Conformation of repaglinide: A solvent dependent structure

    NASA Astrophysics Data System (ADS)

    Chashmniam, Saeed; Tafazzoli, Mohsen

    2017-09-01

    Experimental and theoretical conformational study of repaglinide in chloroform and dimethyl sulfoxide was investigated. By applying potential energy scanning (PES) at B3LYP/6-311++g** and B3LYP-D3/6-311++g** level of theory on rotatable single bonds, four stable conformers (R1-R4) were identified. Spin-spin coupling constant values were obtained from a set of 2D NMR spectra (Hsbnd H COSY, Hsbnd C HMQC and Hsbnd C HMBC) and compared to its calculated values. Interestingly, from 1HNMR and 2D-NOESY NMR, it has been found that repaglinide structure is folded in CDCl3 and cause all single bonds to rotate at an extremely slow rate. On the other hand, in DMSO-d6, with strong solvent-solute intermolecular interactions, the single bonds rotate freely. Also, energy barrier and thermodynamic parameters for chair to chair interconversion was measured (13.04 kcal mol-1) in CDCl3 solvent by using temperature dynamic NMR.

  6. Inferences on the Nature of a Cr(V) or Cr(IV) Species Formed by Reduction of Dichromate by a Bovine Liver Homogenate: NMR and Mass-Spectrometric Studies

    PubMed Central

    Gaggelli, Elena; D'Amelio, Nicola; Gaggelli, Nicola; Bovalini, Lucia; Paffetti, Alessandro; Trabalzini, Lorenza

    2003-01-01

    A low-molecular weight chromium-containing fraction of the material resulting from dichromate reduction by bovine liver homogenate was investigated by NMR and ES-MS. The ES-MS spectrum showed a readily detectable peak at m/z = 786.1. The same molecular weight reasonably agreed with the relatively low diffusion coefficient measured by NMR-DOSY experiments on the main species observed in the 1H NMR spectrum. At least two downfield shifted and broad paramagnetic signals were apparent in the 1H NMR spectrum. Temperature dependence of chemical shift was exploited in order to estimate the diamagnetic shift of the signals in the diamagnetic region of the spectrum. 2D TOCSY, NOESY, COSY and 1H-3C HMQC spectra revealed the presence of aromatic protons (which were assigned as His residues), Gly and some other short chain amino-acids. Combinations of the molecular masses of such components together with acetate (which is present in the solution) and chromium atoms allowed a tentative proposal of a model for the compound. PMID:18365060

  7. Structure of the O-specific polysaccharide of Proteus vulgaris O15 containing a novel regioisomer of N-acetylmuramic acid, 2-acetamido-4-O-[(R)-1-carboxyethyl]-2-deoxy-D-glucose.

    PubMed

    Perepelov, Andrei V; Torzewska, Agnieszka; Shashkov, Alexander S; Ziolkowski, Andrzej; Senchenkova, Sof'ya N; Rozalski, Antoni; Knirel, Yuriy A

    2002-11-29

    An acidic O-specific polysaccharide was obtained by mild acid degradation of the lipopolysaccharide of Proteus vulgaris O15 and studied by sugar and methylation analyses along with 1H and 13C NMR spectroscopy, including 2D COSY, TOCSY, ROESY, and H-detected 1H,(13)C HMQC experiments. The polysaccharide was found to contain an ether of GlcNAc with lactic acid, and the following structure of the repeating unit was established:-->3)-alpha-D-GlcpNAc4(R-Lac)6Ac-(1-->2)-beta-D-GlcpA-(1-->3)-alpha-L-6dTalp2Ac-(1-->3)-beta-D-GlcpNAc-(1-->where L-6dTal and D-GlcNAc4(R-Lac) are 6-deoxy-L-talose and 2-acetamido-4-O-[(R)-1-carboxyethyl]-2-deoxy-D-glucose, respectively. The latter sugar, which to our knowledge has not been hitherto found in nature, was isolated from the polysaccharide by solvolysis with anhydrous triflic acid and identified by comparison with the authentic synthetic compound. Serological studies with the Smith-degraded polysaccharide showed an importance of 2-substituted GlcA for manifesting of the immunospecificity of P. vulgaris O15.

  8. Structural and serological studies of the related O-specific polysaccharides of Proteus vulgaris O21 and Proteus mirabilis O48 having oligosaccharide-phosphate repeating units.

    PubMed

    Bartodziejska, B; Toukach, F V; Vinogradov, E V; Senchenkova, S N; Shashkov, A S; Ziolkowski, A; Czaja, J; Perry, M B; Knirel, Y A; Rozalski, A

    2000-12-01

    The O-specific polysaccharide chains (O-antigens) of the lipopolysaccharides (LPSs) of Proteus mirabilis O48 and Proteus vulgaris O21 were found to have tetrasaccharide and pentasaccharide repeating units, respectively, interlinked by a glycosidic phosphate. Polysaccharides and an oligosaccharide were derived from the LPSs by various degradation procedures and studied by 1H and 13C NMR spectroscopy, including 2D COSY, TOCSY, NOESY, H-detected 1H,13C and 1H,31P HMQC experiments. The following related structures of the repeating units of the O-antigens were established (top: Proteus mirabilis O48; bottom: Proteus vulgaris O21) The O-specific polysaccharide of P. vulgaris O21 has the same structure as that of Hafnia allvei 744 and PCM 1194 [Petersson C., Jachymek, W., Klonowska, A., Lugowski, C., Niedziela, T. & Kenne, L. (1997) Eur. J. Biochem., 245, 668-675], except that the GlcN residue carries the N-acetyl rather than the N-[(R)-3-hydroxybutyryl] group. Serological investigations confirmed the close relatedness of the Proteus and Hafnia O-antigens studied.

  9. Glucosamine and Glucosamine-6-phosphate Derivatives: Catalytic Cofactor Analogs for the glmS Ribozyme

    PubMed Central

    Posakony, Jeffrey J.; Ferré-D'Amaré, Adrian R.

    2013-01-01

    Two analogues of glucosamine-6-phosphate (GlcN6P, 1) and five of glucosamine (GlcN, 2) were prepared for evaluation as catalytic cofactor of the glmS ribozyme, a bacterial gene-regulatory RNA that controls cell wall biosynthesis. Glucosamine and allosamine with 3-azido substitutions were prepared by SN2 reactions of the respective 1,2,4,6-protected sugars; final acidic hydrolysis afforded the fully deprotected compounds as their TFA salts. A 6-phospho-2-aminoglucolactam (31) was prepared from glucosamine in a 13-step synthesis, which included a late-stage POCl3-phosphorylation. A simple and widely applicable 2-step procedure with the triethylsilyl (TES) protecting group was developed to selectively expose the 6-OH group in N-protected glucosamine analogs, which provided another route to chemical phosphorylation. Mitsunobu chemistry afforded 6-cyano (35) and 6-azido (36) analogues of GlcN-(Cbz) and the selectivity for the 6-position was confirmed by NMR (COSY, HMBC, HMQC) experiments. Compound 36 was converted to the fully deprotected 6-azido-GlcN (37) and 2,6-diaminoglucose (38) analogs. A 2-hydroxylamino glucose (42) analogue was prepared via an oxaziridine (41). Enzymatic phosphorylation of 42 and chemical phosphorylation of its 6-OH precursor (43) were possible, but 42 and the 6-phospho product (44) were unstable under neutral or basic conditions. Chemical phosphorylation of the previously described 2-guanidinyl-glucose (46) afforded its 6-phospho analogue (49) after final deprotection. PMID:23578404

  10. New lipoxygenase and cholinesterase inhibitory sphingolipids from Carthamus oxyacantha.

    PubMed

    Dilshad, Muhammad; Riaz, Naheed; Saleem, Muhammad; Shafiq, Nusrat; Ashraf, Muhammad; Ismail, Tayaba; Rafiq, Hafiza Mehwish; Jabbar, Abdul

    2016-08-01

    Two new sphingolipids: oxyacanthin A [(2S,3S,4R)-2-{[(2R,5E)-2-hydroxyoctadec-5-enoyl]amino}hexaeicosane-1,3,4-triol; 1] and B [(2S,3S,4R)-2-{[(2R,5E)-2-hydroxyoctadec-5-enoyl]amino}hexaeicosane-1,3,4-triol-1-O-β-D-glucopyranoside; 2], together with 1-octacosanol, β-sitosterol, β-sitosterol 3-O-β-D-glucopyranoside and luteolin 7-O-β-glucopyranoside were isolated from the methanolic extract of the whole plant of Carthamus oxyacantha. Their structures were elucidated using (1)H and (13)C NMR spectra and 2D NMR analyses (HMQC, HMBC and COSY) in combination with mass spectrometry (EI-MS, HR-EI-MS, FAB-MS and HR-FAB-MS) experiments and in comparison with the literature data of the related compounds. Both the compounds 1 and 2 showed inhibitory potential against lipoxygenase (LOX) in a concentration-dependent manner with IC50 values 83.3 ± 1.3 and 245.7 ± 1.1 µM, whereas compound 2 showed inhibition against enzymes acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) with IC50 values 65.3 ± 0.1 and 93.6 ± 0.1 µM, respectively.

  11. Lignans and neolignans from Stelleropsis antoninae

    PubMed Central

    Gohari, A.R.; Saeidnia, S; Bayati-Moghadam, M; Amin, Gh

    2011-01-01

    Background and the purpose of the study Stelleropsis antoninae Pobed. (Family: Thymelaeaceae) grows wildly as an herbaceous plant in Iran. Most of the Thymelaeaceous plants contain lignans and neolignans, which have important pharmacologically properties. In the present study, the isolation and identification of the main lignans and neolignans of S. antoninae, which has not been previously reported is described and compared to other species. Methods Column (CC) and High Performance Liquid Chromatographic (HPLC) methods were used for the isolation and purification, and 1H-NMR, 13C-NMR, HMBC, HMQC, H-H COSY and MS were employed for the identification of the compounds isolated from the methanol extract. Results From the methanol extract of the aerial parts of S. antoninae four lignans, syringaresinol (1), syringaresinol 4-O-β-D-glucopyranoside (4), syringaresinol 4-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside (5), liriodendrin (6), and two neolignans, 5-methoxylariciresinol 4’-O- β-D-glucopyranoside (3) and dehydrodiconiferyl alcohol 4-O-β -D-glucopyranoside (2) were isolated and identified. Major conclusion The results of this study show that siringaresinol, a well-known bioavtive compound, and its glucosides are the main lignans, and lariciresinol and coniferyl alcohol derivatives are the main neolignans of S. antoninae. PMID:22615643

  12. Preparation and structural characterization of poly-mannose synthesized by phosphoric acid catalyzation under microwave irradiation.

    PubMed

    Wang, Haisong; Cheng, Xiangrong; Shi, Yonghui; Le, Guowei

    2015-05-05

    Poly-mannose with molecular weight of 2.457 kDa was synthesized using d-mannose as substrate and phosphoric acid as catalyst under the condition of microwave irradiation for the first time. The optimum reaction conditions were microwave output power of 900 W, temperature 115°C, proton concentration 2.5 mol/L, and microwave irradiation time 5 min. The actual maximum yield was 91.46%. After purified by Sepherdex G-25 column chromatography, the structural features of poly-mannose were investigated by high-performance anion-exchange chromatography (HPAEC), high-performance gel-permeation chromatography (HPGPC), infrared (IR) spectroscopy, methylation analysis and NMR spectroscopy analysis ((1)H, (13)C, COSY, TOCSY, HMQC, and HMBC). HPAEC analysis showed that the composition of synthetic polysaccharides was d-mannose, its purity was demonstrated by HPGPC as a single symmetrical sharp peak, and additionally IR spectra demonstrated the polymerization of d-mannose. Methylation analysis and NMR spectroscopy revealed that the backbone of poly-mannose consisting of (1→3)-linked β-d-Manp, (1→3)-linked α-d-Manp, and (1→6)-linked α-d-Manp residues, and the main chain were branched at the O-2, O-3, O-4, O-6 position.

  13. Lanostane triterpenoids and sterols from Antrodia camphorata.

    PubMed

    Huang, Hui-Chi; Liaw, Chih-Chuang; Yang, Hsin-Ling; Hseu, You-Cheng; Kuo, Hsiou-Ting; Tsai, Yao-Ching; Chien, Shih-Chang; Amagaya, Sakae; Chen, Yu-Chang; Kuo, Yueh-Hsiung

    2012-12-01

    Four lanostane triterpenes, 3,7,11-trioxo-5α-lanosta-8,24(E)-dien-26-oic acid, methyl 11α-3,7-dioxo-5α-lanosta-8,24(E)-dien-26-oate, methyl 3,7,11,12,15,23-hexaoxo-5α-lanost-8-en-26-oate, and ethyl 3,7,11,12,15,23-hexaoxo-5α-lanost-8-en-26-oate, two sterols, (14α,22E)-14-hydroxyergosta-7,22-diene-3,6-dione and a steroid named as camphosterol A were isolated from a mixture of fruiting bodies and mycelia of solid cultures of Antrodia camphorata. The ¹H and ¹³C NMR spectra of all compounds were fully assigned using a combination of 2D NMR experiments, including COSY, HMQC, HMBC and NOESY sequences. Six compounds were evaluated for cytotoxicity against several human tumor cell lines, all of which has moderate activity.

  14. Antioxidant and Anti-Osteoporotic Activities of Aromatic Compounds and Sterols from Hericium erinaceum.

    PubMed

    Li, Wei; Lee, Sang Hyun; Jang, Hae Dong; Ma, Jin Yeul; Kim, Young Ho

    2017-01-11

    Hericium erinaceum, commonly called lion's mane mushroom, is a traditional edible mushroom widely used in culinary applications and herbal medicines in East Asian countries. In this study, a new sterol, cerevisterol 6-cinnamate (6), was isolated from the fruiting bodies of H. erinaceum together with five aromatic compounds 1-5 and five sterols 7-11. The chemical structures of these compounds were elucidated using chemical and physical methods and comparison of HRESIMS, ¹D-NMR (¹H, (13)C, and DEPT) and 2D-NMR (COSY, HMQC, HMBC, and NOESY) spectra with previously reported data. The antioxidant and anti-osteoporotic activities of extracts and the isolated compounds 1-11 were investigated. All compounds exhibited peroxyl radical-scavenging capacity but only compounds 1, 3, and 4 showed potent reducing capacity. Moreover, compounds 1, 2, 4, and 5 showed moderate effects on cellular antioxidant activity and inhibited the receptor activator of nuclear factor κB ligand (RANKL)-induced osteoclastic differentiation. These results suggested that H. erinaceum could be utilized in the development of natural antioxidant and anti-osteoporotic nutraceuticals and functional foods.

  15. Structure of the O-specific polysaccharide of Proteus vulgaris O4 containing a new component of bacterial polysaccharides, 4,6-dideoxy-4.

    PubMed

    Perepelov, A V; Babicka, D; Senchenkova, S N; Shashkov, A S; Moll, H; Rozalski, A; Zähringer, U; Knirel, Y A

    2001-03-22

    A high-molecular-mass O-specific polysaccharide was obtained by mild acid degradation of Proteus vulgaris O4 lipopolysaccharide followed by GPC. The polysaccharide was studied by chemical methods along with 1H and 13C NMR spectroscopy, including two-dimensional COSY, TOCSY, NOESY, H-detected 1H,13C HMQC, and 1H,13C HMBC experiments. Solvolysis of the polysaccharide with trifluoromethanesulfonic (triflic) acid resulted in a GlcpA-(1 --> 3)-GlcNAc disaccharide and a novel amino sugar derivative, 4,6-dideoxy-4-[N-[(R)-3-hydroxybutyryl]-L-alanyl]amino-D-glucose [Qui4N(HbAla)]. On the basis of the data obtained, the following structure of the tetrasaccharide repeating unit of the O-specific polysaccharide was established: --> 4)-beta-D-GlcpA-(1 --> 3)-beta-D-GlcpNAc-(1 --> 2)-beta-D-Quip4N(HbAla)-(1 --> 3)-alpha-D-Galp-(1 -->. This structure is unique among the O-specific polysaccharides, which is in accordance with classification of the strain studied in a separate Proteus serogroup.

  16. Cu(I) complexes bearing the new sterically demanding and coordination flexible tris(3-phenyl-1-pyrazolyl)methanesulfonate ligand and the water-soluble phosphine 1,3,5-triaza-7-phosphaadamantane or related ligands.

    PubMed

    Wanke, Riccardo; Smoleński, Piotr; da Silva, M Fátima C Guedes; Martins, Luísa M D R S; Pombeiro, Armando J L

    2008-11-03

    The new sterically hindered scorpionate tris(3-phenylpyrazolyl)methanesulfonate (Tpms(Ph))(-) has been synthesized and its coordination behavior toward a Cu(I) center, in the presence of 1,3,5-triaza-7-phosphaadamantane (PTA), N-methyl-1,3,5-triaza-7-phosphaadamantane tetraphenylborate ((mPTA)[BPh4]) or hexamethylenetetramine (HMT) has been studied. The reaction between Li(Tpms(Ph)) (1) and [Cu(MeCN)4][PF6] yields [Cu(Tpms(Ph))(MeCN)] (2) which, upon further acetonitrile displacement on reaction with PTA, HMT, or (mPTA)[BPh4], gives the corresponding complexes [Cu(Tpms(Ph))(PTA)] (3), [Cu(Tpms(Ph))(HMT)] (4), and [Cu(Tpms(Ph))(mPTA)][PF6] (5). All the compounds have been characterized by (1)H, (31)P, (13)C, COSY or HMQC-NMR, IR, elemental analysis, and single crystal X-ray diffraction. In the complexes (3) and (5), which bear a phosphine ligand (i.e., PTA and mPTA, respectively), the new scorpionate ligand shows the typical N, N, N-coordination mode, whereas in (2) and (4), bearing a N-donor ligand (i.e., MeCN and HMT, respectively), it binds the metal via the N,N,O chelating mode, involving the sulfonate moiety.

  17. Molecular, spectroscopic and thermal studies on catechol, 4,5-dibromocatechol, resorcinol, hydroquinone and 4-4‧-dihydroxybiphenyl derivatives armed with benzothiazole moieties

    NASA Astrophysics Data System (ADS)

    Alshargabi, Arwa; Yeap, Guan-Yeow; Mahmood, Wan Ahmad Kamil; Samikannu, Rakesh

    2013-05-01

    A new series of catechol, 4,5-dibromocatechol, resorcinol, hydroquinone and 4-4'-dihydroxybiphenyl derivatives possessing two benzothiazole moieties at respective positions of 1,2, 1,3, 1,4 and/or 4,4' has successfully been synthesized. The molecular structures were fully elucidated by spectroscopic techniques (1H NMR, 13C NMR and two dimensional COSY, HMBC, HMQC, DEPT-135 and DEPT-90). The connectivity study between the cause of using different core systems in the target compounds and the anisotropic behavior as inferred from phase transition temperature and relevant morphology studies has led to some unique features arising from this series. Compounds with ortho substituent exhibit enantiotropic N and SmA phases. The analogues containing resorcinol and 4,4'-disubstituentbiphenyl show enanotiotropic nematic behavior while the hydroquinone derivative induces the formation of monotropic nematogen. An extensive study to further substantiate the relationship between the stability of the nematic phase and associated transition temperatures due to different core systems is also reported.

  18. Databases of Conformations and NMR Structures of Glycan Determinants.

    PubMed

    Sarkar, Anita; Drouillard, Sophie; Rivet, Alain; Perez, Serge

    2015-12-01

    The present study reports a comprehensive nuclear magnetic resonance (NMR) characterization and a systematic conformational sampling of the conformational preferences of 170 glycan moieties of glycosphingolipids as produced in large-scale quantities by bacterial fermentation. These glycans span across a variety of families including the blood group antigens (A, B and O), core structures (Types 1, 2 and 4), fucosylated oligosaccharides (core and lacto-series), sialylated oligosaccharides (Types 1 and 2), Lewis antigens, GPI-anchors and globosides. A complementary set of about 100 glycan determinants occurring in glycoproteins and glycosaminoglycans has also been structurally characterized using molecular mechanics-based computation. The experimental and computational data generated are organized in two relational databases that can be queried by the user through a user-friendly search engine. The NMR ((1)H and (13)C, COSY, TOCSY, HMQC, HMBC correlation) spectra and 3D structures are available for visualization and download in commonly used structure formats. Emphasis has been given to the use of a common nomenclature for the structural encoding of the carbohydrates and each glycan molecule is described by four different types of representations in order to cope with the different usages in chemistry and biology. These web-based databases were developed with non-proprietary software and are open access for the scientific community available at http://glyco3d.cermav.cnrs.fr. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. Structural characterisation and antimutagenic activity of a novel polysaccharide isolated from Sepiella maindroni ink.

    PubMed

    Liu, Chunhui; Li, Xiaodong; Li, Yuhua; Feng, You; Zhou, Shuai; Wang, Fengshan

    2008-10-15

    A new heteropolysaccharide, named as SIP, was isolated from the ink of cuttlefish, Sepiella maindroni, by enzymolysis, anion-exchange and gel-permeation chromatography and tested for its antimutagenic activity. It was homogeneous with a molecular weight of 1.13×10(4)Da by HPSEC-MALLS analysis. SIP contained glucuronic acid, mannose, N-acetylgalactosamine, and fucose in a molar ratio of 1:1:2:2. Its structural characteristics were investigated and elucidated by methylation analysis, GLC-MS, and NMR ((1)H, (13)C, H-H COSY, HMQC, HMBC, TOCSY and NOESY). The hexasaccharide repeating unit of SIP was found to be a backbone composed of fucose, N-acetylgalactosamine and mannose in a molar ratio of 2:2:1, and with a single branch of glucuronic acid at the C-3 position of mannose. According to the micronucleus test, SIP could significantly reduce the frequency of micronucleated cells in polychromatic erythrocytes and reticulocytes induced by cyclophosphamide in tumor-bearing mice, which revealed that SIP presented strong antimutagenic activity. Copyright © 2008 Elsevier Ltd. All rights reserved.

  20. Synthesis, Fourier transform infrared, 1D and 2D NMR spectral studies on the conformation of two new cholesteryl 4-alkoxyphenyl-4‧ benzoates

    NASA Astrophysics Data System (ADS)

    Yeap, Guan-Yeow; Ha, Sie-Tiong; Ito, Masato M.; Boey, Peng-Lim; Mahmood, Wan Ahmad Kamil

    2004-01-01

    Two new cholesteryl 4-alkoxyphenyl-4‧-benzoates (CnH2n+1OC6H4C6H4COOCh), where Ch represents cholesteryl moiety and n=10 and 16) have been synthesized and their molecular orientation at ambient temperature were studied. The structure determination on these compounds was performed in solid state by infrared spectroscopy based on vibrational analysis wherein the cholesteryl-phenyl and phenyl-aliphatic carbon linkages were concluded. Their molecular structures were further ascertained through the 1H and 13C NMR spectra along with two-dimensional COSY, NOESY, ROESY, 1H-13C HMQC and HMBC. The long-range connectivity as concluded from the NOESY, ROESY and HMBC spectra together with the related data led to a postulation that the title compounds in the liquid state exist in the conformation whereby the cholesteryl moiety was not lying along the entire molecular long axis. The cholesteryl fragment was presumed to be bent at the ester linkage of OC-O and the phenyl rings located between cholesteryl and alkoxy chain group are not coplanar.

  1. Callyaerins A-F and H, new cytotoxic cyclic peptides from the Indonesian marine sponge Callyspongia aerizusa.

    PubMed

    Ibrahim, Sabrin R M; Min, Cho Cho; Teuscher, Franka; Ebel, Rainer; Kakoschke, Christel; Lin, Wenhan; Wray, Victor; Edrada-Ebel, RuAngelie; Proksch, Peter

    2010-07-15

    Bioassay guided fractionation of the EtOAc fraction of the sponge Callyspongia aerizusa yielded seven new cytotoxic cyclic peptides callyaerins A-F (1-6) and H (8). Their structures were determined using extensive 1D (1H, 13C and DEPT) and 2D (COSY, HMQC, HMBC, TOCSY, and ROESY) NMR and mass spectral (ESI and HRESI-TOF) data. All compounds were cyclic peptides containing ring systems of 5-9 amino acids and side chains of 2-5 amino acids in length. An unusual (Z)-2,3-diaminoacrylic acid unit provided the template for ring closure and afforded the linkage to the peptidic side chain which was always initiated with a proline moiety. All peptides contained three or more proline residues and the remaining residues were predominantly hydrophobic residues with all amino acids present in the l form. Callyaerins A-F (1-6) and H (8) showed biological activity in antibacterial assays and in various cytotoxicity assays employing different tumour cell-lines (L5178Y, HeLa, and PC12). Callyaerins E (5) and H (8) exhibited strong activity against the L5178Y cell line with ED50 values of 0.39 and 0.48 microM, respectively. On the other hand, callyaerin A (1) showed strong inhibitory properties towards C. albicans. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  2. Two new acetylated flavonoid glycosides from Centaurium spicatum L.

    PubMed

    Allam, Ahmed E; El-Shanawany, Mohamed A; Backheet, Enaam Y; Nafady, Alaa M; Takano, Fumihide; Ohta, Tomihisa

    2012-04-01

    Two new acetylated flavonol glycosides, quercetin 3-O-[(2,4-diacetyl-α-L-rhamnopyranosyl)-(1→6)]-2,4-diacetyl-β-D-galactopyranoside (1) and quercetin 3-O-[(2,4-diacetyl-α-L-rhamnopyranosyl)-(1→6)]-3,4-diacetyl-β-D-galactopyranoside (2), in addition to two known acetylated quercetin glycosides quercetin 3-O-[(2,3,4-triacetyl-α-L-rhamnopyranosyl)-(1→6)-β-D-galactopyranoside (3) and quercetin 3-O-[(2,3,4-triacetyl-α-L-rhamnopyranosyl)-(1→6)-3-acetyl-β-D-galactopyranoside (4), were isolated from the aerial part of Centaurium spicatum (L.) Fritsch (Gentianaceae). Structure elucidation, especially the localization of the acetyl groups, and complete (1)H and (13)C NMR assignments of these biologically active compounds were carried out using one- and two-dimensional NMR measurements, including (1)H- and (13)C-NMR, DEPT-135, H-H COSY, HMQC and HMBC, in addition to HR-FAB/MS experiments.

  3. Synthesis and characterization of N,N'-bis[4-[1-(2-hidroxyethoxy)]salicylidine]-phenyldiamine-nickel(II)] complex

    NASA Astrophysics Data System (ADS)

    Shamsuddin, Roshatiara binti; Karim, Nurul Huda Abd

    2016-11-01

    N,N'-bis[4-[1-(2-hidroxyethoxy)]salicylidine]-phenyldiamine-nickel(II) complex has been synthesized by treating N,N'-bis-4-(hydroxysalicylidene)-phenylenediamine-nickel(II) complex with 2-chloroethanol and nickel(II) acetate tetrahydrate in ethanol solvent. The resulting complex formed was characterized using standard spectroscopic and structural techniques which includes 1H, 13C, COSY and HMQC NMR spectroscopy, FTIR spectroscopy and ESI-MS spectrometry. The 1H NMR spectrum displayed all the expected signals with right integration and multiplicity. The formation of Schiff base can be seen at 8.54 ppm for the formation of diimine and the disappearance of aldehyde peak at 9.88 ppm corresponding to the starting material confirms the full conversion. The presence of resonance peak at 3.76 ppm and 4.00 ppm corresponding to the ethyl group of the hydroxyl side chain also confirm the formation of the complex. The FTIR spectrum of the complex confirmed the expected C=N band at 1577 cm-1 and C-H for sp3 stretching band at 2878 cm-1. The formation of the new complex was also confirmed by ESI(+)-MS spectrometry, which showed the molecular peak with adduct ions at [M+K]+=531 a.m.u and [M+Na]+=515 a.m.u.

  4. Physicochemical characterization and toxicological evaluation of plant-based anionic polymers and their nanoparticulated system for ocular delivery.

    PubMed

    Pathak, Deepa; Kumar, Prashant; Kuppusamy, Gowthamarajan; Gupta, Ankur; Kamble, Bhagyashree; Wadhwani, Ashish

    2014-12-01

    The water-soluble fractions of mucilages and gum from the seeds of fenugreek, isphagula and mango bark exudate were isolated, purified and characterized using X-ray diffraction (XRD) spectrometry, Fourier transform infrared spectroscopy (FT-IR), maldi/GC-MS, elemental analysis, 1D ((1)H and (13)C) and 2D (HMQC, COSY) nuclear magnetic resonance spectroscopy (NMR). The fenugreek mucilage was identified to be a galactomannan chain consisting of 4 units of galactose attached to the backbone of 6 mannose units in 1:1.5 ratio. The isphagula mucilage was identified to be an arabinoxylan polysaccharide chain consisting of 4 units of arabinofuranose attached to the backbone of 9 xylopyrannose units in 1:3 ratio. The mango gum showed the presence of amylose, α-arabinofuranosyl and β-galactopyranosyl, respectively. The characterized mucilages and gum were individually formulated into nanoparticulate system using their complementarily charged polymer chitosan. The particles were observed to be spherical in shape in the range of 61.5-90 nm having zetapotential between 31 and 34 mV and PDI of 0.097-0.241. The prepared nanoparticles were observed to be nonirritant and nontoxic in vitro and in vivo upto 2000 μg/ml. Therefore, these mucilages and gum can be the alternatives of anionic polymers for the ocular drug delivery system.

  5. Chemical constituents and biological activities of Senecio aegyptius var. discoideus Boiss.

    PubMed

    Hassan, Wafaa; Al-Gendy, Amal; Al-Youssef, Hanan; El-Shazely, Assem

    2012-01-01

    A new eremophilane sesquiterpene, 1-beta-hydroxy-8-oxoeremophila-7,9-dien-12-oic acid (1), in addition to two known flavonol glycosides, rutin (2) and quercetin-3-O-glucoside-7-O-rutinoside (3), was isolated from the ethyl acetate fraction obtained from the aqueous alcoholic extract of the aerial parts of Senecio aegyptius var. discoideus Boiss. (family Asteraceae). The chemical structures of the isolated compounds were established by 1D and 2D NMR analysis (1H, 13C, COSY, HMQC, HMBC), MS and UV data, and through comparison with the literature. The ethyl acetate fraction and the isolated rutin showed significant cytotoxic activity against colorectal carcinoma (HCT 116) and to less extent against brain (U 251) and breast carcinoma (MCF 7). The ethyl acetate fraction showed a significant level of activity against Klebsiella pneumoniae, while the total extract showed the best antifungal activity against Candida albicans and Saccharomyces cerevisiae. DPPH radical scavenging activity of the ethyl acetate fraction was significant (96.7%) when compared to ascorbic acid. It also showed anti-inflammatory activity but no diuretic effect.

  6. Lipoxygenase inhibitory sphingolipids from Launaea nudicaulis.

    PubMed

    Riaz, Naheed; Parveen, Shehla; Saleem, Muhammad; Ali, Muhammad Shaiq; Malik, Abdul; Ashraf, Muhammad; Afzal, Iftikhar; Jabbar, Abdul

    2012-01-01

    Four new sphingolipids: nudicaulin A [(2S,3S,4R,14E)-2-{[octadecanoyl]amino}tetraeicos-14-ene-1,3,4-triol; 1], nudicaulin B [(2S,3S,4R,14E)-2-{[(2R)-2-hydroxyoctadecanoyl]amino}tetraeicos-14-ene-1,3,4-triol; 2], nudicaulin C [(2S,3S,4R,14E)-2-{[(2R)-2-hydroxyoctadecanoyl]amino}tetraeicos-14-ene-1,3,4-triol-1-O-β-D-glucopyranoside; 3], and nudicaulin D [(2S,3S,4R)-2-{[(2R,3S,12E)-2,3-dihydroxyeicos-12-enoyl]amino}octadecane-1,3,4-triol; 4] together with 1-hexatriacontanol, β-sitosterol, octadecyl 4-hydroxycinnamate, elaidic acid, cholesta-5,22-diene-3,7-diol, oleanolic acid, apigenin, and β-sitosterol 3-O-β-D-glucopyranoside were isolated from the methanolic extract of the whole plant of Launaea nudicaulis. Their structures were elucidated using ¹H and ¹³C NMR spectra and 2D NMR analyses (HMQC, HMBC, and COSY) in combination with mass spectrometry (EI-MS, HR-EI-MS, FAB-MS, and HR-FAB-MS) experiments and comparison with literature data of related compounds. Compounds 1-4 displayed moderate inhibitory potential against enzyme lipoxygenase in concentration-dependent manner with IC₅₀ value ranges 103-193 μM.

  7. Antileishmanial activity of parthenolide, a sesquiterpene lactone isolated from Tanacetum parthenium.

    PubMed

    Tiuman, Tatiana Shioji; Ueda-Nakamura, Tânia; Garcia Cortez, Diógenes Aparício; Dias Filho, Benedito Prado; Morgado-Díaz, José Andrés; de Souza, Wanderley; Nakamura, Celso Vataru

    2005-01-01

    The in vitro activity of parthenolide against Leishmania amazonensis was investigated. Parthenolide is a sesquiterpene lactone purified from the hydroalcoholic extract of aerial parts of Tanacetum parthenium. This isolated compound was identified through spectral analyses by UV, infrared, (1)H and (13)C nuclear magnetic resonance imaging, DEPT (distortionless enhancement by polarization transfer), COSY (correlated spectroscopy), HMQC (heteronuclear multiple-quantum coherence), and electron spray ionization-mass spectrometry. Parthenolide showed significant activity against the promastigote form of L. amazonensis, with 50% inhibition of cell growth at a concentration of 0.37 microg/ml. For the intracellular amastigote form, parthenolide reduced by 50% the survival index of parasites in macrophages when it was used at 0.81 microg/ml. The purified compound showed no cytotoxic effects against J774G8 macrophages in culture and did not cause lysis in sheep blood when it was used at higher concentrations that inhibited promastigote forms. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis with gelatin as the substrate showed that the enzymatic activity of the enzyme cysteine protease increased following treatment of the promastigotes with the isolated compound. This finding was correlated with marked morphological changes induced by parthenolide, such as the appearance of structures similar to large lysosomes and intense exocytic activity in the region of the flagellar pocket, as seen by electron microscopy. These results provide new perspectives on the development of novel drugs with leishmanicidal activities obtained from natural products.

  8. Antileishmanial Activity of Parthenolide, a Sesquiterpene Lactone Isolated from Tanacetum parthenium

    PubMed Central

    Tiuman, Tatiana Shioji; Ueda-Nakamura, Tânia; Garcia Cortez, Diógenes Aparício; Dias Filho, Benedito Prado; Morgado-Díaz, José Andrés; de Souza, Wanderley; Nakamura, Celso Vataru

    2005-01-01

    The in vitro activity of parthenolide against Leishmania amazonensis was investigated. Parthenolide is a sesquiterpene lactone purified from the hydroalcoholic extract of aerial parts of Tanacetum parthenium. This isolated compound was identified through spectral analyses by UV, infrared, 1H and 13C nuclear magnetic resonance imaging, DEPT (distortionless enhancement by polarization transfer), COSY (correlated spectroscopy), HMQC (heteronuclear multiple-quantum coherence), and electron spray ionization-mass spectrometry. Parthenolide showed significant activity against the promastigote form of L. amazonensis, with 50% inhibition of cell growth at a concentration of 0.37 μg/ml. For the intracellular amastigote form, parthenolide reduced by 50% the survival index of parasites in macrophages when it was used at 0.81 μg/ml. The purified compound showed no cytotoxic effects against J774G8 macrophages in culture and did not cause lysis in sheep blood when it was used at higher concentrations that inhibited promastigote forms. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis with gelatin as the substrate showed that the enzymatic activity of the enzyme cysteine protease increased following treatment of the promastigotes with the isolated compound. This finding was correlated with marked morphological changes induced by parthenolide, such as the appearance of structures similar to large lysosomes and intense exocytic activity in the region of the flagellar pocket, as seen by electron microscopy. These results provide new perspectives on the development of novel drugs with leishmanicidal activities obtained from natural products. PMID:15616293

  9. Constituents of Musa x paradisiaca cultivar with the potential to induce the phase II enzyme, quinone reductase.

    PubMed

    Jang, Dae Sik; Park, Eun Jung; Hawthorne, Michael E; Vigo, Jose Schunke; Graham, James G; Cabieses, Fernando; Santarsiero, Bernard D; Mesecar, Andrew D; Fong, Harry H S; Mehta, Rajendra G; Pezzuto, John M; Kinghorn, A Douglas

    2002-10-23

    A new bicyclic diarylheptanoid, rel-(3S,4aR,10bR)-8-hydroxy-3-(4-hydroxyphenyl)-9-methoxy-4a,5,6,10b-tetrahydro-3H-naphtho[2,1-b]pyran (1), as well as four known compounds, 1,2-dihydro-1,2,3-trihydroxy-9-(4-methoxyphenyl)phenalene (2), hydroxyanigorufone (3), 2-(4-hydroxyphenyl)naphthalic anhydride (4), and 1,7-bis(4-hydroxyphenyl)hepta-4(E),6(E)-dien-3-one (5), were isolated from an ethyl acetate-soluble fraction of the methanol extract of the fruits of Musa x paradisiaca cultivar, using a bioassay based on the induction of quinone reductase (QR) in cultured Hepa1c1c7 mouse hepatoma cells to monitor chromatographic fractionation. The structure and relative stereochemistry of compound 1 were elucidated unambiguously by one- and two-dimensional NMR experiments ((1)H NMR, (13)C NMR, DEPT, COSY, HMQC, HMBC, and NOESY) and single-crystal X-ray diffraction analysis. Isolates 1-5 were evaluated for their potential cancer chemopreventive properties utilizing an in vitro assay to determine quinone reductase induction and a mouse mammary organ culture assay.

  10. Constituents of Asparagus officinalis evaluated for inhibitory activity against cyclooxygenase-2.

    PubMed

    Jang, Dae Sik; Cuendet, Muriel; Fong, Harry H S; Pezzuto, John M; Kinghorn, A Douglas

    2004-04-21

    As part of a project directed toward the discovery of new cancer chemopreventive agents from plants, two new natural products, asparagusic acid anti-S-oxide methyl ester (1) and asparagusic acid syn-S-oxide methyl ester (2), a new acetylenic compound, 2-hydroxyasparenyn [3',4'-trans-2-hydroxy-1-methoxy-4-[5-(4-methoxyphenoxy)-3-penten-1-ynyl]-benzene] (3), as well as eleven known compounds, asparenyn (4), asparenyol (5), (+/-)-1-monopalmitin (6), ferulic acid (7), 1,3-O-di-p-coumaroylglycerol (8), 1-O-feruloyl-3-O-p-coumaroylglycerol (9), blumenol C, (+/-)-epipinoresinol, linoleic acid, 1,3-O-diferuloylglycerol, and 1,2-O-diferuloylglycerol, were isolated from an ethyl acetate-soluble fraction of the methanol extract of the aerial parts of Asparagus officinalis (Asparagus), using a bioassay based on the inhibition of cyclooxygenase-2 to monitor chromatographic fractionation. The structures of compounds 1-3 were elucidated by 1D- and 2D-NMR experiments ((1)H NMR, (13)C NMR, DEPT, COSY, HMQC, HMBC and NOESY). All the isolates were evaluated for their inhibitory effects against both cyclooxygenase-1 and -2, with the most active compound being linoleic acid.

  11. Cholesterol and its derivatives, are the principal steroids isolated from the leech species Hirudo medicinalis.

    PubMed

    Zipser, B; Bradford, J J; Hollingsworth, R I

    1998-08-01

    Steroids were isolated from the blood-sucking leech species Hirudo medicinalis and their structure was studied with one- and two-dimensional NMR spectroscopy (DQF-COSY and HMQC), GC-MS and ESI-MS spectrometry. Fractionating leech lipid using silicic acid chromatography led to the isolation of cholesterol in an early chloroform-eluted peak. Only minor traces of cholest-4-en-3-one, 4 beta-methylcholesterol, and sitosterol were present. The subsequent acetone-eluted fraction contained steroidtriols that were further purified by preparative TLC; these included cholest-7-ene-3,5,6 triol, cholest-4,7-diene-3,6,15 triol and to a lesser amount, cholestane-3,5,6 triol. A developmental study on cholesterol content in the leech showed that it is also the principal steroid in embryonic and freshly hatched leeches prior to feeding. The abundance of cholesterol, comprising approximately 5% of the total leech lipid, suggests that H. medicinalis, a blood sucking leech, has adapted itself fully to its mammalian host in terms of its steroid content. It remains to be seen whether lipids are directly transferred from the host to the parasite or whether leeches have evolved mechanisms to synthesize their own steroids.

  12. Synthesis, Characterization and Antitumor Activity of cis-bis(acylthioureato) platinum(II) Complexes, cis-[PtL2] [HL1=N,N-Diphenyl-N'-Benzoylthiourea or HL2=N,N-diphenyl-N'-(p-nitrobenzoyl)thiourea

    PubMed Central

    Hernández, Wilfredo; Muñoz, Juan Carlos; Beyer, Lothar; Schröder, Uwe; Ferreira, Jorge; Pavani, Mario

    2003-01-01

    A low-molecular weight chromium-containing fraction of the material resulting from dichromate reduction by bovine liver homogenate was investigated by NMR and ES-MS. The ES-MS spectrum showed a readily detectable peak at m/z 786.1. The same molecular weight reasonably agreed with the relatively low diffusion coefficient measured by NMR-DOSY experiments on the main species observed in the 1H NMR spectrum. At least two downfield shifted and broad paramagnetic signals were apparent in the 1H NMR spectrum. Temperature dependence of chemical shift was exploited in order to estimate the diamagnetic shift of the signals in the diamagnetic region of the spectrum. 2D TOCSY, NOESY, COSY and 1H-13C HMQC spectra revealed the presence of aromatic protons (which were assigned as His residues), Gly and some other short chain amino-acids. Combinations of the molecular masses of such components together with acetate (which is present in the solution) and chromium atoms allowed a tentative proposal of a model for the compound. PMID:18365059

  13. Identification of MMP-1 and MMP-9 inhibitors from the roots of Eleutherococcus divaricatus, and the PAMPA test.

    PubMed

    Załuski, Daniel; Mendyk, Ewaryst; Smolarz, Helena D

    2016-01-01

    The purpose of this study was the isolation of metalloproteinases MMP-1 and MMP-9 inhibitors from the chloroform extract of the Eleutherococcus divaricatus roots. Using GC-MS, (1)H and (13)C NMR, HMQC, HMBC, COSY and DEPT, (+)-sesamin has been identified as a new anti-MMP inhibitor. We report for the first time that (+)-sesamin inhibited MMP-1 and MMP-9 activity in 40% and 17%, respectively. The high inhibitory potential has been shown by ursolic acid (90.9% and 89.8% for MMP-1 and MMP-9). In the PAMPA test, the Pe value for sesamin was established as 17.4 × 10(-6) cm/s, that for ursolic acid as 30.0 × 10(- 6) cm/s. Verapamil and theophylline were used as a positive and negative control (Pe 42.1 and 2.9 × 10(-6) cm/s). To our best knowledge, no information was available on this activity of sesamin and other compounds. These studies provide a biochemical basis for the regulation of MMP-1 and MMP-9 by E. divaricatus compounds.

  14. Biosynthesis of xyrrolin, a new cytotoxic hybrid polyketide/non-ribosomal peptide pyrroline with anticancer potential, in Xylaria sp. BCC 1067.

    PubMed

    Phonghanpot, Suranat; Punya, Juntira; Tachaleat, Anuwat; Laoteng, Kobkul; Bhavakul, Vanida; Tanticharoen, Morakot; Cheevadhanarak, Supapon

    2012-04-16

    A gene from Xylaria sp. BCC 1067, pks3, that encodes a putative 3660-residue hybrid polyketide synthase (PKS)/non-ribosomal peptide synthetase (NRPS) was characterised by targeted gene disruption in combination with comprehensive product identification. Studies of the features of a corresponding mutant, YA3, allowed us to demonstrate that pks3 is responsible for the synthesis of a new pyrroline compound, named xyrrolin, in the wild-type Xylaria sp. BCC 1067. The structure of xyrrolin was established by extensive spectroscopic and spectrometric analyses, including low- and high-resolution MS, IR, (1)H NMR, (13)C NMR, (13)C NMR with Dept135, HMQC 2D NMR, HMBC 2D NMR and COSY 2D NMR. On the basis of the Pks3 domain organisation and the chemical structure of xyrrolin, we proposed that biosynthesis of this compound requires the condensation of a tetraketide and an L-serine unit, followed by Dieckmann or reductive cyclisation and enzymatic removal of ketone residue(s). Bioassays of the pure xyrrolin further displayed cytotoxicity against an oral cavity (KB) cancer cell line.

  15. Synthesis, structural, conformational and DFT studies of N-3 and O-4 alkylated regioisomers of 5-(hydroxypropyl)pyrimidine

    NASA Astrophysics Data System (ADS)

    Salihović, Mirsada; Osmanović, Amar; Špirtović-Halilović, Selma; Roca, Sunčica; Meščić, Andrijana; Vujisić, Ljubodrag; Trifunović, Snežana; Završnik, Davorka; Sofić, Emin

    2015-07-01

    Because of the great pharmacological potential of the pyrimidine motif, novel C-5 substituted N-3 acyclic and O-4 acyclic pyrimidine derivatives were prepared as an interesting class of compounds for biological evaluation. Introduction of the 2,3-dihydroxypropyl (DHP) and penciclovir (PCV)-like side chains to 2-methoxypyrimidin-4-one (2) afforded a mixture of N- and O-acyclic pyrimidine nucleosides in the ratio of 54: 29 (3:4) and 57:21 (5:6) with N-3 isomer being dominant. Distinction between N- and O-alkylated pyrimidine moiety was deduced from extensive experimental FT-IR, HPLC-MS and 1D (1H, 13C) and 2D (COSY, HMQC and HMBC) NMR analyses. The N-, O-regioisomers were also examined by computational method at density functional theory (DFT) RB3LYP/6-31G(d), 6-31G∗∗ and 6-31+G∗ levels. DFT global chemical reactivity descriptors (total energy, chemical hardness, electronic chemical potential and electrophilicity) were calculated for the isomers and used to predict and describe their relative stability and reactivity. The chemical reactivity indices were related to the C2sbnd N3sbnd C4 bond angle. Theoretical predictions can be used to compare chemical reactivity and stability with future biological evaluation and behaviour of these compounds.

  16. Monoterpene Unknowns Identified Using IR, [to the first power]H-NMR, [to the thirteenth power]C-NMR, DEPT, COSY, and HETCOR

    ERIC Educational Resources Information Center

    Alty, Lisa T.

    2005-01-01

    A study identifies a compound from a set of monoterpenes using infrared (IR) and one-dimensional (1D) nuclear magnetic resonance (NMR) techniques. After identifying the unknown, each carbon and proton signal can be interpreted and assigned to the structure using the information in the two-dimensional (2D) NMR spectra, correlation spectroscopy…

  17. Heteronuclear three-dimensional NMR spectroscopy. Natural abundance sup 13 C chemical shift editing of sup 1 H- sup 1 H COSY spectra

    SciTech Connect

    Fesik, S.W.; Gampe, R.T. Jr.; Zuiderweg, E.R.P. )

    1989-01-18

    It has been demonstrated that heteronuclear 3D NMR spectroscopy can be effectively applied to small molecules with {sup 13}C at natural abundance. A 78mM solution of the aminoglycoside, kanamycin A was used for this experiment. The heteronuclear 3D NMR spectroscopy is shown to be a useful method for resolving spectral overlap in all frequency domains. 10 refs., 2 figs.

  18. Pulse shaping to improve performance of NMR multiple-pulse sequences: 2-D solvent-suppressed cosy of vitamin B 1 in water

    NASA Astrophysics Data System (ADS)

    McCoy, Mark; Warren, Warren S.

    1987-01-01

    Grafted "narrow reject" pulse shapes, whicch were shown previously to be capable of uniformly exciting a wide range of resonance frequencies with a sharp null directly on resonance for solvent suppression, are combined to generate multiple-pulse sequences. In particular, we show that two-dimensional solvent-suppressed spectra can be obtained with such pulses. This is the first application of pulse Grafting to high-resolution, multiple-pulse NMR spectroscopy.

  19. Growth of YBa sub 2 Cu sub 3 O sub 7 minus x thin films on Si with a CoSi sub 2 buffer layer

    SciTech Connect

    Luo, L.; Muenchausen, R.E.; Maggiore, C.J. ); Jimenez, J.R.; Schowalter, L.J. )

    1991-01-28

    By using the pulsed laser deposition technique, high-temperature superconducting YBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} (YBCO) films were grown on Si(001) with a 36 nm single-crystal {l angle}001{r angle} oriented CoSi{sub 2} buffer layer. The films, grown at a substrate temperature of {similar to}700 {degree}C, have a metallic resistive temperature dependence with zero resistance at 85 K. X-ray diffraction, scanning electron microscopy, and ion channeling studies show that the YBCO films are polycrystalline but are strongly {ital c}-axis oriented normal to the Si substrate. Diffusion at the interface between the YBCO film and silicide buffer layer was minimized. This is essential to the growth of high-temperature superconducting films on Si substrates.

  20. Monoterpene Unknowns Identified Using IR, [to the first power]H-NMR, [to the thirteenth power]C-NMR, DEPT, COSY, and HETCOR

    ERIC Educational Resources Information Center

    Alty, Lisa T.

    2005-01-01

    A study identifies a compound from a set of monoterpenes using infrared (IR) and one-dimensional (1D) nuclear magnetic resonance (NMR) techniques. After identifying the unknown, each carbon and proton signal can be interpreted and assigned to the structure using the information in the two-dimensional (2D) NMR spectra, correlation spectroscopy…

  1. Antiplatelet aggregation triterpene saponins from the barks of Ilex rotunda.

    PubMed

    Fan, Zhen; Zhou, Lian; Xiong, Tianqin; Zhou, Jinsong; Li, Qingguo; Tan, Qinglong; Zhao, Zhongxiang; Jin, Jing

    2015-03-01

    Four new triterpene saponins, rotundinosides A-D (1-4) and seven known triterpene saponins (5-11) were isolated from a methanol extract of the barks of Ilex rotunda Thunb. The new saponins were characterized as 3-O-β-d-glucopyranosy1-(1→2)-β-d-xylopyranosyl siaresinolic acid 28-O-β-d-glucopyranoside (1), 3-O-[β-d-glucopyranosy1-(1→2)-β-d-xylopyranosyl]-3β,19α-dihydroxyurs-12-en-28-oic-O-β-d-glucopranosy1ester (2), 3-O-[α-l-rhamnopyranosyl-(1→2)-β-d-glucopyranosy1-(1→2)-α-l-arabinopyranosyl]-3β,19α-dihydroxyurs-12-en-28-oic-O-β-d-glucopyranosy1 ester (3), and 3-O-α-l-rhamanopyranosyl-(1→2)-β-d-glucopyranosy1-(1→2)-α-l-arabinopyranosyl ilexgenin B 28-O-β-d-glucopyranosy1 ester (4), respectively. Their structures were established by extensive spectroscopic analysis, including HSQC, HMBC, (1)H-(1)H COSY, NOESY and acid hydrolysis, and also by the comparison of their spectroscopic data with those of related compounds. The known compounds 5-11 were all obtained from this species for the first time. The biological activity of compounds 1-11 against ADP induced platelet aggregation in rabbit plasma was determined. Among the tested compounds 1, 3, 5 and 10 exhibited strong inhibition of platelet aggregation in vitro, with IC50 values of 11.4±2.2, 10.4±1.3, 13.2±2.4, and 15.1±3.4μM, respectively.

  2. NMR Metabolic profiling of green tea (Camellia sinensis L.) leaves grown at Kemuning, Indonesia

    NASA Astrophysics Data System (ADS)

    Wahyuni, D. S. C.; Kristanti, M. W.; Putri, R. K.; Rinanto, Y.

    2017-01-01

    Green tea (Camellia sinensis L.) has been famous as a beverage and natural medicine. It contains a broad range of primary and secondary metabolites i.e. polyphenols. Nuclear Magnetic Resonance (NMR) has been widely used for metabolic profiling in medicinal plants. It provides a very fast and detailed analysis of the biomolecular composition of crude extracts. Moreover, an NMR spectrum is a physical characteristic of a compound and thus highly reproducible. Therefore, this study aims to profile metabolites of three different varieties of green tea C. Sinensis grown in Kemuning, Middle Java. Three varieties of green tea collected on Kemuning (TR1 2025, Gambung 4/5, and Chiaruan 143) were used in this study. 1H-NMR spectra were recorded at 230C on a 400 MHz Agilent WB (Widebore). The analysis was performed on dried green tea leaves and analyzed by 1H-NMR, 2D-J-resolved and 1H-1H correlated spectroscopy (COSY). MestRenova version 11.0.0 applied to identify metabolites in samples. A 1H-NMR spectrum of tea showed amino acids and organic acids signal at the area δ 0.8-4.0. These were theanine, alanine, threonine, succinic acid, aspartic acid, lactic acid. Anomeric protons of carbohydrate were shown by the region of β-glucose, α-glucose, fructose and sucrose. The phenolic region was depicted at area δ 5.5-8.5. Epigallocatechin derivates and caffeine were detected in the tea leaves. The detail compound identification was observed and discussed in the text.

  3. Metabolism and excretion of 1-hydroxymethylpyrene, the proximate metabolite of the carcinogen 1-methylpyrene, in rats.

    PubMed

    Bendadani, Carolin; Steinhauser, Lisa; Albert, Klaus; Glatt, Hansruedi; Monien, Bernhard H

    2016-07-29

    1-Methylpyrene, an alkylated polycyclic aromatic hydrocarbon and environmental carcinogen, is activated by side-chain hydroxylation to 1-hydroxymethylpyrene (1-HMP) and subsequent sulfo conjugation to the DNA-reactive 1-sulfooxymethylpyrene. In addition to the bioactivation, processes of metabolic detoxification and transport greatly influence the genotoxicity of 1-methylpyrene. For a better understanding of 1-HMP detoxification in vivo we studied urinary and fecal metabolites in rats following intraperitoneal doses of 19.3mg 1-HMP/kg body weight (5 rats) or the same dose containing 200μCi [(14)C]1-HMP/kg body weight (2 rats). After 48h, 48.0% (rat 1) and 29.1% (rat 2) of the radioactivity was recovered as 1-HMP in the feces. Six major metabolites were observed by UV and on-line radioactivity detection in urine samples and feces after HPLC separation. The compounds were characterized by mass spectrometry, (1)H NMR and (1)H-(1)H COSY NMR spectroscopy, which allowed assigning tentative molecular structures. Two prominent metabolites, 1-pyrene carboxylic acid (M-6) and the acyl glucuronide of 1-pyrene carboxylic acid (M-5) accounted for 17.7% (rat 1) and 25.2% (rat 2) of the overall radioactive dose. Further, we detected the acyl glucuronide of 6-hydroxy-1-pyrene carboxylic acid (M-1) and 8-sulfooxy-1-pyrene carboxylic acid (M-3) together with two regioisomers of M-3 (M-2 and M-4) differing in position of the sulfate group at the pyrene ring. In urine samples, the radioactivity of 1-pyrene carboxylic acid and its five derivatives amounted to 32.4% (rat 1) or 45.5% (rat 2) of the total [(14)C]1-HMP dose. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  4. Resolution-optimized NMR measurement of (1)D(CH), (1)D(CC) and (2)D(CH) residual dipolar couplings in nucleic acid bases.

    PubMed

    Boisbouvier, Jérôme; Bryce, David L; O'neil-Cabello, Erin; Nikonowicz, Edward P; Bax, Ad

    2004-11-01

    New methods are described for accurate measurement of multiple residual dipolar couplings in nucleic acid bases. The methods use TROSY-type pulse sequences for optimizing resolution and sensitivity, and rely on the E.COSY principle to measure the relatively small two-bond (2)D(CH) couplings at high precision. Measurements are demonstrated for a 24-nt stem-loop RNA sequence, uniformly enriched in (13)C, and aligned in Pf1. The recently described pseudo-3D method is used to provide homonuclear (1)H-(1)H decoupling, which minimizes cross-correlation effects and optimizes resolution. Up to seven (1)H-(13)C and (13)C-(13)C couplings are measured for pyrimidines (U and C), including (1)D(C5H5), (1)D(C6H6), (2)D(C5H6), (2)D(C6H5), (1)D(C5C4), (1)D(C5C6), and (2)D(C4H5). For adenine, four base couplings ((1)D(C2H2), (1)D(C8H8), (1)D(C4C5), and (1)D(C5C6)) are readily measured whereas for guanine only three couplings are accessible at high relative accuracy ((1)D(C8H8), (1)D(C4C5), and (1)D(C5C6)). Only three dipolar couplings are linearly independent in planar structures such as nucleic acid bases, permitting cross validation of the data and evaluation of their accuracies. For the vast majority of dipolar couplings, the error is found to be less than +/-3% of their possible range, indicating that the measurement accuracy is not limiting when using these couplings as restraints in structure calculations. Reported isotropic values of the one- and two-bond J couplings cluster very tightly for each type of nucleotide.

  5. NMR investigations of dinuclear, single-anion bridged copper(II) metallacycles: structure and antiferromagnetic behavior in solution.

    PubMed

    Reger, Daniel L; Pascui, Andrea E; Pellechia, Perry J; Ozarowski, Andrew

    2013-11-04

    The nuclear magnetic resonance (NMR) spectra of single-anion bridged, dinuclear copper(II) metallacycles [Cu2(μ-X)(μ-L)2](A)3 (L(m) = m-bis[bis(1-pyrazolyl)methyl]benzene: X = F(-), A = BF4(-); X = Cl(-), OH(-), A = ClO4(-); L(m)* = m-bis[bis(3,5-dimethyl-1-pyrazolyl)methyl]benzene: X = CN(-), F(-), Cl(-), OH(-), Br(-), A = ClO4(-)) have relatively sharp (1)H and (13)C NMR resonances with small hyperfine shifts due to the strong antiferromagnetic superexchange interactions between the two S = 1/2 metal centers. The complete assignments of these spectra, except X = CN(-), have been made through a series of NMR experiments: (1)H-(1)H COSY, (1)H-(13)C HSQC, (1)H-(13)C HMBC, T1 measurements and variable-temperature (1)H NMR. The T1 measurements accurately determine the Cu···H distances in these molecules. In solution, the temperature dependence of the chemical shifts correlate with the population of the paramagnetic triplet (S = 1) and diamagnetic singlet (S = 0) states. This correlation allows the determination of antiferromagnetic exchange coupling constants, -J (Ĥ = -JŜ1Ŝ2), in solution for the L(m) compounds 338(F(-)), 460(Cl(-)), 542(OH(-)), for the L(m)* compounds 128(CN(-)), 329(F(-)), 717(Cl(-)), 823(OH(-)), and 944(Br(-)) cm(-1), respectively. These values are of similar magnitudes to those previously measured in the solid state (-Jsolid = 365, 536, 555, 160, 340, 720, 808, and 945 cm(-1), respectively). This method of using NMR to determine -J values in solution is an accurate and convenient method for complexes with strong antiferromagnetic superexchange interactions. In addition, the similarity between the solution and solid-state -J values of these complexes confirms the information gained from the T1 measurements: the structures are similar in the two states.

  6. Structures of two O-chain polysaccharides of Citrobacter gillenii O9a,9b lipopolysaccharide. A new homopolymer of 4-amino-4,6-dideoxy-D-mannose (perosamine).

    PubMed

    Lipiński, Tomasz; Zatonsky, George V; Kocharova, Nina A; Jaquinod, Michel; Forest, Eric; Shashkov, Alexander S; Gamian, Andrzej; Knirel, Yuriy A

    2002-01-01

    Mild acid degradation of the lipopolysaccharide of Citro- bacter gillenii O9a,9b released a polysaccharide (PS), which was found to consist of a single monosaccharide, 4- acetamido-4,6-dideoxy-d-mannose (d-Rha4NAc, N-acetyl-d-perosamine). PS was studied by methylation analysis and (1)H-NMR and (13)C-NMR spectroscopy, using two-dimensional (1)H,(1)H COSY, TOCSY, NOESY, and H-detected (1)H,(13)C heteronuclear correlation experiments. It was found that PS includes two structurally different polysaccharides: an alpha1-->2-linked homopolymer of N-acetyl-d-perosamine [-->2)-alpha-d-Rhap4NAc-(1-->, PS2] and a polysaccharide composed of tetrasaccharide repeating units (PS1) with the following structure: -->3)-alpha-d-Rhap4NAc-(1-->2)-alpha-d-Rhap4NAc-(1-->2)-alpha-d-Rhap4NAc-(1-->3)-alpha-d-Rhap4 N Ac2Ac-(1--> where the degree of O-acetylation of a 3-substituted Rha4NAc residue at position 2 is approximately 70%. PS could be fractionated into PS1 and PS2 by gel-permeation chromatography on TSK HW-50S. Matrix-assisted laser desorption ionization MS data indicate sequential chain elongation of both PS1 and PS2 by a single sugar unit, with O-acetylation in PS1 beginning at a certain chain length. Anti-(C. gillenii O9a,9b) serum reacted with PS1 in double immunodiffusion and immunoblotting, whereas neither PS2 nor the lipopolysaccharide of Vibrio cholerae O1 with a structurally related O-chain polysaccharide were reactive.

  7. The new Schiff base 4-[(4-Hydroxy-3-fluoro-5-methoxy-benzylidene)amino]-1,5-dimethyl-2-phenyl-1,2-dihydro-pyrazol-3-one: Experimental, DFT calculational studies and in vitro antimicrobial activity

    NASA Astrophysics Data System (ADS)

    İskeleli, Nazan Ocak; Alpaslan, Yelda Bingöl; Direkel, Şahin; Ertürk, Aliye Gediz; Süleymanoğlu, Nevin; Ustabaş, Reşat

    2015-03-01

    The synthesized Schiff base, 4-[(4-Hydroxy-3-fluoro-5-methoxy-benzylidene)amino]-1,5-dimethyl-2-phenyl-1,2-dihydro-pyrazol-3-one (I), has been characterized by 13C NMR, 1H NMR, 2D NMR (1H-1H COSY and 13C APT), FT-IR, UV-vis and X-ray single-crystal techniques. Molecular geometry of the compound I in the ground state, vibrational frequencies and chemical shift values have been calculated by using the density functional method (DFT) with 6-311++G(d,p) basis set. The obtained results indicate that optimized geometry can well reflect the crystal structural parameters. The differences between experimental and calculated results of FT-IR and NMR have supported the existence of intermolecular (O-H⋯O type) and intramolecular (C-H⋯O type) hydrogen bonds in the crystal structure. Molecular electrostatic potential (MEP), frontier molecular orbital analysis (HOMO-LUMO) and electronic absorption spectra were carried out at B3LYP/6-311G++(d,p). HOMO-LUMO electronic transition of 3.92 eV is due to contribution of the bands the n → π∗. The antimicrobial activity of the compound I was determined against the selected 11 bacteria and 8 fungi by microdilution broth assay with Alamar Blue. In vitro studies showed that the compound I has no antifungal effect for selected fungal isolates. However, the compound I shows remarkable antibacterial effect for the bacteria; Streptococcus pneumoniae, Haemophilus influenzae and Enterococcus faecalis.

  8. Direct Analysis of Free and Sulfite-Bound Carbonyl Compounds in Wine by Two-Dimensional Quantitative Proton and Carbon Nuclear Magnetic Resonance Spectroscopy.

    PubMed

    Nikolantonaki, Maria; Magiatis, Prokopios; Waterhouse, Andrew L

    2015-11-03

    Recent developments that have accelerated 2D NMR methods and improved quantitation have made these methods accessible analytical procedures, and the large signal dispersion allows for the analysis of complex samples. Few natural samples are as complex as wine, so the application to challenges in wine analysis look promising. The analysis of carbonyl compounds in wine, key oxidation products, is complicated by a multitude of kinetically reversible adducts, such as acetals and sulfonates, so that sample preparation steps can generate complex interferences. These challenges could be overcome if the compounds could be quantified in situ. Here, two-dimensional ((1)H-(1)H) homonuclear and heteronuclear ((13)C-(1)H) single quantum correlations (correlation spectroscopy, COSY, and heteronuclear single quantum coherence, HSQC) nuclear magnetic resonance spectra of undiluted wine samples were observed at natural abundance. These techniques achieve simultaneous direct identification and quantitation of acetaldehyde, pyruvic acid, acetoin, methylglyoxal, and α-ketoglutaric acid in wine with only a small addition of D2O. It was also possible to observe and sometimes quantify the sulfite, hydrate, and acetal forms of the carbonyl compounds. The accuracy of the method was tested in wine samples by spiking with a mixture of all analytes at different concentrations. The method was applied to 15 wine samples of various vintages and grape varieties. The application of this method could provide a powerful tool to better understand the development, evolution, and perception of wine oxidation and insight into the impact of these sulfite bound carbonyls on antimicrobial and antioxidant action by SO2.

  9. Structural characterization of highly glucosylated crocins and regulation of their biosynthesis during flower development in Crocus

    PubMed Central

    Ahrazem, Oussama; Rubio-Moraga, Angela; Jimeno, Maria L.; Gómez-Gómez, Lourdes

    2015-01-01

    Crocin biosynthesis in Crocus has been proposed to proceed through a zeaxanthin cleavage pathway catalyzed by carotenoid cleavage dioxygenase 2 (CCD2), and followed by glucosylation reactions catalyzed by CsGT2 (UGT74AD1). In Crocus ancyrensis flowers, crocins with eight (crocin-1), seven (crocin-2), and six glucose (crocin-3) moieties accumulated both in stigma and tepals. We have characterized the structure of these highly glucosylated crocins and follow up their accumulation by high-resolution liquid chromatography coupled with diode array detector along the development of both tissues, and coupled to the isolation and analysis of the expression of eighteen genes (PSY-I, PSY-II, PDS-(I-V), ISO-ZDS, ZDS, CtrISO, LYC-I and II, BCH, CaCCD2, UGT74AD2-5) related with the apocarotenoid metabolism in C. ancyrensis tepals and stigmas. Structure elucidation of crocin-1 and crocin-2 was done by the combined use of 1D and 2D [1H, 1H] (gCOSY and TOCSY and ROESY) and [1H-13C] NMR experiments, revealing that for crocin-1 was all-trans-crocetin O-[β-D- Glucopyranosyl)-(1→4)-(β-D-glucopyranosyl)-(1→2)]-O-[β-D-glucopyranosyl-(1→6)]-β-D-glucopyranosyl diester, while crocin-2 showed an identical structure except for the absence of one glucose residue in one end of the molecule. Crocins accumulation was not synchronically regulated in stigma and tepals, although in both cases crocins accumulation parallels tissue development, decreasing at anthesis. The expression of the carotenogenic genes PSY, ZDS-V, BCH, and LCY-II was correlated with crocins accumulation. In addition, CaCCD2 and only one of the four glucosyltransferase encoding genes, UGT74AD2, were highly expressed, and the expression was correlated with high levels of crocins accumulation in stigma and tepals. PMID:26582258

  10. Solid state and solution properties of lanthanide(III) complexes of a tetraiminodiphenolate macrocyclic ligand. X-ray structure, 1H NMR and luminescence spectral studies

    NASA Astrophysics Data System (ADS)

    Bag, Pradip; Dutta, Supriya; Flörke, Ulrich; Nag, Kamalaksha

    2008-11-01

    The lanthanide(III) complexes of composition [Ln(LH 2)(H 2O) 3Cl]Cl 2 (Ln = La-Lu and Y, 1- 15) derived from the tetraiminodiphenolate macrocyclic ligand L 2- have been prepared and characterized. In these compounds, the two uncoordinated imine nitrogens of the macrocycle are protonated and hydrogen-bonded with the metal-bound phenolate oxygens and thereby provide a zwitterionic structure to the ligand. The X-ray crystal structure of the compounds of La and Nd have been determined and they are found to be isostructural. The coordination polyhedra for the eight-coordinated metal centre in the complex cation [Ln(N 2O 2)(O 3Cl)] 2+ can be described as distorted square antiprism. Intermolecular hydrogen-bondings involving the three coordinated water molecules and the two uncoordinated chloride ions give rise to the 2-D network in which the chlorides are triply hydrogen-bridged and the water molecules are doubly hydrogen-bridged. Moreover, the aromatic rings in this network are involved in π-π interaction in two different ways. 1H NMR spectra of the complexes in (CD 3) 2SO have been studied. The spectral assignments for the paramagnetic complexes of Ce-Eu have been made from { 1H- 1H} COSY spectra and longitudinal relaxation time ( T1) measurements. It is inferred that the complex species [Ln(LH 2){(CD 3) 2SO} 4] 3+ that exist in solution are isostructural for the compounds of La-Eu. The contact and pseudo-contact contribution to the isotropic paramagnetic shifts in the complexes of Ce-Eu have been estimated. The luminescence spectra of the complexes of La, Sm, Eu and Tb have been studied in methanol-ethanol (1:4) glassy matrix and in the solid state at 77 K, and the quantum yields have been estimated.

  11. The new Schiff base 4-[(4-Hydroxy-3-fluoro-5-methoxy-benzylidene)amino]-1,5-dimethyl-2-phenyl-1,2-dihydro-pyrazol-3-one: experimental, DFT calculational studies and in vitro antimicrobial activity.

    PubMed

    İskeleli, Nazan Ocak; Alpaslan, Yelda Bingöl; Direkel, Şahin; Ertürk, Aliye Gediz; Süleymanoğlu, Nevin; Ustabaş, Reşat

    2015-03-15

    The synthesized Schiff base, 4-[(4-Hydroxy-3-fluoro-5-methoxy-benzylidene)amino]-1,5-dimethyl-2-phenyl-1,2-dihydro-pyrazol-3-one (I), has been characterized by (13)C NMR, (1)H NMR, 2D NMR ((1)H-(1)H COSY and (13)C APT), FT-IR, UV-vis and X-ray single-crystal techniques. Molecular geometry of the compound I in the ground state, vibrational frequencies and chemical shift values have been calculated by using the density functional method (DFT) with 6-311++G(d,p) basis set. The obtained results indicate that optimized geometry can well reflect the crystal structural parameters. The differences between experimental and calculated results of FT-IR and NMR have supported the existence of intermolecular (O-H⋯O type) and intramolecular (C-H⋯O type) hydrogen bonds in the crystal structure. Molecular electrostatic potential (MEP), frontier molecular orbital analysis (HOMO-LUMO) and electronic absorption spectra were carried out at B3LYP/6-311G++(d,p). HOMO-LUMO electronic transition of 3.92eV is due to contribution of the bands the n→π∗. The antimicrobial activity of the compound I was determined against the selected 11 bacteria and 8 fungi by microdilution broth assay with Alamar Blue. In vitro studies showed that the compound I has no antifungal effect for selected fungal isolates. However, the compound I shows remarkable antibacterial effect for the bacteria; Streptococcus pneumoniae, Haemophilus influenzae and Enterococcus faecalis. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. The Effect of Terminal Substitution on the Helical Carbon Structure of Fluoro-Alkane Chains: a Pure Rotational Study of CH2OH-Cn-1F2n-1 (n = 4, 5,& 6)

    NASA Astrophysics Data System (ADS)

    Schwartz, Aaron Z. A.; Maturo, Mark P.; Obenchain, Daniel A.; Cooke, S. A.

    2016-06-01

    Continuing a series of studies to investigate the change in structure of hydrocarbons as the amount of fluorination is increased to varying degrees of substitution, we present a survey on the change in the helical nature of the fluorinated carbon backbone when a -CH2OH group is substituted for a terminal - CF3 group. Spectra for 1H,1H-heptafluorobutan-1-ol, 1H,1H-nonafluoropentan-1-ol, and 1H,1H-undecafluorohexan-1-ol were collected separately using a chirped-pulse FTMW spectrometer in the range of 7-13 GHz. Only one conformation was observed for each molecule. Additional measurements of the 1H,1H-heptafluorobutan-1-ol were completed using a Balle-Flygare cavity instrument. Assignments of the singly-substituted 13C isotopologues of the 1H,1H-heptafluorobutan-1-ol were also measured. A comparison of both ab initio and experimental structures will be presented.

  13. C-Glucoside xanthone from the stem bark extract of Bersama engleriana

    PubMed Central

    Djemgou, Pierre C.; Hussien, Taha A.; Hegazy, Mohamed-Elamir F.; Ngandeu, François; Neguim, Gilles; Tane, Pierre; Mohamed, Abou-El-Hamd H.

    2010-01-01

    Background: The genus Bersama belongs to the Melianthaceae family and comprises of four species (B. swinnyi, B. yangambiensis, B. abyssinica, and B. engleriana) all of which are very high trees; the latter two detected species are found in Cameroon. Previous phytochemical investigation on B. yangambiensis, B. swinnyi, and B. abyssinica led to the isolation of triterpenes, saponins, flavonoids, and xanthones. Method: The stem bark of B. engleriana were collected in the village, Baham near Bafoussam city, Cameroon in August 2003 and identifi ed by Dr. Onana National Herbaruim, Yaoundι, Cameroon. The air dried and powdered stem bark of B. engleriana (1 kg) was extracted at room temperature with CH2Cl2-MeOH (1:1) 5 L for 48 hours. The mixture of the solvent was removed by evaporation to yield 200 g of crude extract. The latter was then dissolved in CH2Cl2 to give the CH2Cl2 soluble fraction of 5 g and a remaining gum of 195 g. Part of the remaining gum (22 g) was dissolved in water and extracted four times with butanol to give 12 g of red oil; which was then separated by paper chromatography, with butanol-acetic acid-water (4:1:5), to give 3 g of orange gum; purification was carried out on HPLC with MeOH (100%) to yield 2 g of mangiferin (1) as red oil. The CH2Cl2 soluble extract was eluted on silica gel n-hexane-CH2Cl2 gradient ratio and Sephadex LH-20 (n-hexane -CH2Cl2 -MeOH, (7:4:0.5) to afford compounds swinniol (2), Δ4-stigmaster-3β-ol (3), 4-methylstigmaster-5,23-dien-3β-ol(4). Results: Herein, we carried out a phytochemical study of the stem bark of B. engleriana, and we report herein the isolation and structural elucidation of mangiferin, in addition to three triterpenes, previously reported from other species of the genus.[35] The assignment of the signals of mangiferin was determined using 1H, 13C-NMR, and 2D-NMR spectral data (HMQC, COSY, HMBC). The terpenoids were identifi ed by comparison of their 1H and 13C-NMR spectra with the literature data

  14. NMR structure analysis of uniformly 13C-labeled carbohydrates.

    PubMed

    Fontana, Carolina; Kovacs, Helena; Widmalm, Göran

    2014-06-01

    In this study, a set of nuclear magnetic resonance experiments, some of them commonly used in the study of (13)C-labeled proteins and/or nucleic acids, is applied for the structure determination of uniformly (13)C-enriched carbohydrates. Two model substances were employed: one compound of low molecular weight [(UL-(13)C)-sucrose, 342 Da] and one compound of medium molecular weight ((13)C-enriched O-antigenic polysaccharide isolated from Escherichia coli O142, ~10 kDa). The first step in this approach involves the assignment of the carbon resonances in each monosaccharide spin system using the anomeric carbon signal as the starting point. The (13)C resonances are traced using (13)C-(13)C correlations from homonuclear experiments, such as (H)CC-CT-COSY, (H)CC-NOESY, CC-CT-TOCSY and/or virtually decoupled (H)CC-TOCSY. Based on the assignment of the (13)C resonances, the (1)H chemical shifts are derived in a straightforward manner using one-bond (1)H-(13)C correlations from heteronuclear experiments (HC-CT-HSQC). In order to avoid the (1) J CC splitting of the (13)C resonances and to improve the resolution, either constant-time (CT) in the indirect dimension or virtual decoupling in the direct dimension were used. The monosaccharide sequence and linkage positions in oligosaccharides were determined using either (13)C or (1)H detected experiments, namely CC-CT-COSY, band-selective (H)CC-TOCSY, HC-CT-HSQC-NOESY or long-range HC-CT-HSQC. However, due to the short T2 relaxation time associated with larger polysaccharides, the sequential information in the O-antigen polysaccharide from E. coli O142 could only be elucidated using the (1)H-detected experiments. Exchanging protons of hydroxyl groups and N-acetyl amides in the (13)C-enriched polysaccharide were assigned by using HC-H2BC spectra. The assignment of the N-acetyl groups with (15)N at natural abundance was completed by using HN-SOFAST-HMQC, HNCA, HNCO and (13)C-detected (H)CACO spectra.

  15. In vitro evaluation of the cytotoxic and trypanocidal activities of Ampelozizyphus amazonicus (Rhamnaceae).

    PubMed

    Rosas, L V; Cordeiro, M S C; Campos, F R; Nascimento, S K R; Januário, A H; França, S C; Nomizo, A; Toldo, M P A; Albuquerque, S; Pereira, P S

    2007-05-01

    Ampelozizyphus amazonicus Ducke is a tree commonly found in the Amazon region and an extract of its stem bark is popularly used as an antimalarial and anti-inflammatory agent and as an antidote to snake venom. Ursolic acid; five lupane type triterpenes: betulin, betulinic acid, lupenone, 3beta-hydroxylup-20(29)-ene-27,28-dioic acid, and 2alpha,3beta-dihydroxylup-20(29)-ene-27,28-dioic acid, and three phytosteroids: stigmasterol, sitosterol and campesterol, have been isolated from stem extracts of A. amazonicus Ducke. Their structures were characterized by spectral data including COSY and HMQC. In an in vitro biological screening of the isolated compounds, 3beta-hydroxylup-20(29)-ene-27,28-dioic acid was cytotoxic against the SKBR-3 human adenocarcinoma cell line (1 to 10 mg/mL), while 2alpha,3beta-dihydroxylup-20(29)-ene-27,28-dioic acid exhibited cytotoxicity against both SKBR-3 human adenocarcinoma and C-8161 human melanoma tumor cell lines (>0.1 mg/mL). In the present study, different extracts and some fractions of this plant were also investigated for trypanocidal activity due to the presence of pentacyclic triterpenes. The triterpene classes are potent against Trypanosoma cruzi. The bioassays were carried out using blood collected from Swiss albino mice by cardiac puncture during the parasitemic peak (7th day) after infection with the Y strain of T. cruzi. The results obtained showed that A. amazonicus is a potential source of bioactive compounds since its extracts and fractions isolated from it exhibited in vitro parasite lysis against trypomastigote forms of T. cruzi at concentrations >100 microg/mL. Fractions containing mainly betulin, lupenone, 3beta-hydroxylup-20(29)-ene-27,28-dioic acid, and 2alpha,3beta-dihydroxylup-20(29)-ene-27,28-dioic acid showed more activity than crude extracts.

  16. Simultaneous determination of three diarylheptanoids and an alpha-tetralone derivative in the green walnut husks (Juglans regia L.) by high-performance liquid chromatography with photodiode array detector.

    PubMed

    Liu, Junxi; Meng, Min; Li, Chen; Huang, Xinyi; Di, Duolong

    2008-05-09

    By optimizing extraction, separation and analytical conditions, a reliable and accurate high-performance liquid chromatographic (HPLC) method coupled with photodiode array detector (DAD) at room temperature is developed for simultaneous determination of three diarylheptanoids (juglanin A, juglanin B, rhoiptelol) and an alpha-tetralone derivative (regiolone) in methanol extracts from the green walnut husks (Juglans regia L.) The sample pretreatment process involved the reflux extraction using methanol as the extract with a ratio of liquor to sample of 15 mL/g. The separation was achieved on a SinoChrom ODS-AP C(18) column with gradient elution using acetonitrile and 2% (v/v) acetic acid in water. The intra-day and inter-day precision (RSD%) for the analytes ranged from 1.08 to 1.51 and 0.60 to 1.13, respectively. The average recoveries obtained were from 88.4% to 96.2% for the analytes with RSDs below 3.13%. The correlation coefficients of the calibration curve exceeded 0.999. The detection limits were 0.51, 0.25, 0.32 and 0.35 ng at a signal-to-noise ratio of 3, respectively. Quantitative analyses of the samples from different grown sites and in obtained different months showed that the contents of the analytes varied significantly. The method was then successfully applied for the detection and isolation of a new diarylheptanoid derivative in the green walnut husks (J. regia L.). The structure of the new compound was elucidated by various spectroscopic methods including 2D NMR techniques (COSY, HMQC, HMBC), HR-ESI-MS and X-ray single-crystal diffraction analysis.

  17. Anti-spasmodic action of crude methanolic extract and a new compound isolated from the aerial parts of Myrsine africana

    PubMed Central

    2011-01-01

    Background Myrsine africana is an herbaceous plant that is traditionally used as appetizer and carminative. Locally, it is used for the treatment of pulmonary tuberculosis, rheumatism and diarrhea by healers. The aims of the current study were to screen the crude methanol extract obtained from the aerial parts (leaves and stem) of M. africana, for antispasmodic actions on isolated tissues and further to subject the ethyl acetate (EtOAc) fraction of plant to column chromatography for isolation of pure compounds. Methods The antispasmodic action of the crude methanol extract was measured on the spontaneous rabbit's jejunum preparations at concentration 0.01, 0.03, 0.1, 0.3, 1.0, 5.0 and 10.0 mg/ml. The crude extract was also applied, in similar concentrations, on KCl (80 mM) induced contractions to explain its possible mode of action. Results A new compound Myrsigenin was isolated from the EtOAc fraction of M. africana. The structure of the compound was identified with the help of 13C-NMR, 1H-NMR, HMBC, HMQC, NOESY and COSY. The plant crude methanol extract showed a significant antispasmodic action on rabbit jejunum and abolished the tissue contraction completely at concentration of 5.0 mg/ml. Conclusion The study concludes that the methanol crude extract of aerial parts of M. africana has antispasmodic action possibly through the calcium channel blocking mechanisms. A new compound Myrsigenin was isolated from the EtOAc fraction of the plant. PMID:21733176

  18. Chemical constituents and their antibacterial activity from the tropical endophytic fungus Diaporthe sp. F2934.

    PubMed

    Sousa, J P B; Aguilar-Pérez, M M; Arnold, A E; Rios, N; Coley, P D; Kursar, T A; Cubilla-Rios, L

    2016-06-01

    To isolate, characterize and determine the antibacterial activities of compounds produced by the endophytic fungus Diaporthe sp. F2934, cultivated on malt extract agar. The fungus was cultivated aseptically in Petri dishes containing malt extract agar at 25°C for 15 days. Crude extract was obtained from mycelium using ethyl acetate and sonication, and was fractioned using classic chromatography and HPLC. The structures of phomosines and chromanones were established by NMR experiments including HMQC, HMBC and COSY. Their molecular formulas were determined by ESI-TOFMS. We obtained six compounds: (1) 4H-1-benzopyra-4-one-2,3-dihydro-5-hydroxy-2,8-dimetyl, (2) 4H-1-benzopyran-4-one-2,3-dihydro-5-hydroxy-8-(hydroxylmethyl)-2-methyl, (3) 4H-1-benzopyra-4-one-2,3-dihydro-5-methoxyl-2,8-dimetyl, (4) phomosine A, (5) phomosine D and (6) phomosine C. Isolated compounds 1, 2 and 5 were inactive against 15 micro-organisms, but phomosines A and C were active against diverse Gram-negative and Gram-positive bacteria. A group of new chromanones and known phomosines have been isolated from the genus Diaporthe (Diaporthe sp. F2934). The results obtained confirm the wide chemical diversity produced by endophytic fungi, specifically the genus Diaporthe. In addition, phomosines A and C may be considered as antimicrobial agents that can be used to guide the development of new antibiotics. Our phylogenetic analysis places Diaporthe sp. F2934 as sister to the Diaporthe cynaroidis clade. Three chromanones were isolated and identified, for the first time, using crude extract obtained from Diaporthe F2934. From this extract phomosines A, C and D were also purified. Regarding Staphylococcus aureus, the inhibition zone diameter (IZD) for phomosine A was 20% higher than the standard drug, vancomycin. When cultivated as described here, Diaporthe sp. F2934 produced new and antimicrobial compounds. © 2016 The Society for Applied Microbiology.

  19. Towards Elucidating Carnosic Acid Biosynthesis in Lamiaceae: Functional Characterization of the Three First Steps of the Pathway in Salvia fruticosa and Rosmarinus officinalis.

    PubMed

    Božić, Dragana; Papaefthimiou, Dimitra; Brückner, Kathleen; de Vos, Ric C H; Tsoleridis, Constantinos A; Katsarou, Dimitra; Papanikolaou, Antigoni; Pateraki, Irini; Chatzopoulou, Fani M; Dimitriadou, Eleni; Kostas, Stefanos; Manzano, David; Scheler, Ulschan; Ferrer, Albert; Tissier, Alain; Makris, Antonios M; Kampranis, Sotirios C; Kanellis, Angelos K

    2015-01-01

    Carnosic acid (CA) is a phenolic diterpene with anti-tumour, anti-diabetic, antibacterial and neuroprotective properties that is produced by a number of species from several genera of the Lamiaceae family, including Salvia fruticosa (Cretan sage) and Rosmarinus officinalis (Rosemary). To elucidate CA biosynthesis, glandular trichome transcriptome data of S. fruticosa were mined for terpene synthase genes. Two putative diterpene synthase genes, namely SfCPS and SfKSL, showing similarities to copalyl diphosphate synthase and kaurene synthase-like genes, respectively, were isolated and functionally characterized. Recombinant expression in Escherichia coli followed by in vitro enzyme activity assays confirmed that SfCPS is a copalyl diphosphate synthase. Coupling of SfCPS with SfKSL, both in vitro and in yeast, resulted in the synthesis miltiradiene, as confirmed by 1D and 2D NMR analyses (1H, 13C, DEPT, COSY H-H, HMQC and HMBC). Coupled transient in vivo assays of SfCPS and SfKSL in Nicotiana benthamiana further confirmed production of miltiradiene in planta. To elucidate the subsequent biosynthetic step, RNA-Seq data of S. fruticosa and R. officinalis were searched for cytochrome P450 (CYP) encoding genes potentially involved in the synthesis of the first phenolic compound in the CA pathway, ferruginol. Three candidate genes were selected, SfFS, RoFS1 and RoFS2. Using yeast and N. benthamiana expression systems, all three where confirmed to be coding for ferruginol synthases, thus revealing the enzymatic activities responsible for the first three steps leading to CA in two Lamiaceae genera.

  20. A novel diterpene skeleton: identification of a highly aromatic, cytotoxic and antioxidant 5-methyl-10-demethyl-abietane-type diterpene from Premna serratifolia.

    PubMed

    Habtemariam, Solomon; Varghese, George K

    2015-01-01

    Premna serratifolia Linn. (syn: . P. corymbosa (Burm. f.) Merr., P. integrifolia L. and P. obtusifolia R. Br.) is a member of the Verbenaceae family that is extensively used in the Ayurvedic system of medicine in India. As part of our continuous pharmacological and phytochemical studies on medicinal plants, we have screened the methanolic extracts of leaves, root bark (RB) and root wood of P. serratifolia for cytotoxic activity against two cancer cell lines: SHSY-5Y neuroblastoma and B16 melanoma cells. The RB extract that showed promising activity was fractionated using solvents of increasing polarity followed by a combination of Sephadex LH-20 column and Combiflash chromatography as well as HPLC to afford the active principle. Comprehensive spectroscopic analysis including 1D and 2D NMR (COSY, HMQC, HMBC, NOESY) and MS analysis revealed the identity of the isolated compound as 11,12,16-trihydroxy-2-oxo-5-methyl-10-demethyl-abieta-1[10],6,8,11,13-pentene that appears to be a novel compound based on a new diterpene skeleton. The cytotoxic activity of the isolated compound was 21 and 23 times higher than the crude extract against the SHSY-5Y and B16 cells, respectively. The novel compound also possesses in vitro antioxidant effects as evidenced by the DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging effect where an IC50 value of 20.4 ± 1.3 μM was obtained. In comparison, the positive control, caffeic acid, showed an IC50 value of 14.4 ± 1.6 μM.

  1. Bio-active compounds from Euphorbia cornigera Boiss.

    PubMed

    Baloch, Imam Bakhsh; Baloch, Musa Kaleem; Baloch, Ahmad Khan

    2009-08-01

    Euphorbia cornigera Boiss. (Euphorbiaceae) roots extracted in various organic solvents were tested against Biomphalaria glabrata snails as molluscicide using Bayluscide as a control. Among these, acetone extract was found to be the most active (LC(50)=17.5 microg L(-1)) as compared to Bayluscide. The application of HPLC fractionation yielded ten (1-10) N-(2-aminobenzoyl)anthraniloy esters. Structure and the relative configuration of all the compounds were established through spectroscopic (UV, IR (1)H, (13)C NMR, 2-D NMR, HSQC, HMQC, HMBC, COSY-45 degrees , TOCSY, HOHAHA, HOESY, ROESY, NOESY, SECSY, NOE and mass measurements) techniques. On these basis the esters are named as: 3-O-[N-(2-aminobenzoyl)]-5-O-acetyl-20-O-angelylingenol (1), 3-O-[N-(2-aminobenzoyl)]anthraniloyl-5-O-angelyl-20-O-acetylingenol (2), 3-O-acetyl-5-O-[N-(2-aminobenzoyl)]anthraniloyl-20-O-angelylingenol (3), 3-O-acetyl-5-O-angelyl-20-O-[N-(2-aminobenzoyl)]anthraniloylingenol (4), 3-O-angelyl-5-O-acetyl-20-O-[N-(2-aminobenzoyl)]-anthraniloylingenol (5), 3-O-angelyl-5-O-[N-(2-aminobenzoyl)]anthraniloyl-20-O-acetylingenol (6), 3,20-O-diacetyl-5-O-[N-(2-aminobenzoyl)]anthraniloylingenol (7), 5,20-O-diacetyl-3-O-[N-(2-aminobenzoyl)]anthraniloylingenol (8), 3-O-[N-(2-aminobenzoyl)]anthraniloyl-20-O-acetylingenol (9) and 20-O-[N-(2-aminobenzoyl)]anthraniloyl-3-O-acetylingenol (10). The literature reveals that compounds 1-8 are new from plant kingdom, whereas 9 and 10 are known but not reported from this source earlier. Their molluscicidal activity (in terms of LC(50)) showed that all the compounds were 1.3-2.2 times more toxic than Bayluscide except 5 and 6.

  2. Easy oxidative addition of the carbon-halogen bond by dimethylplatinum(II) complexes containing a related series of diimine ligands: Synthesis, spectral characterization and crystal structure

    NASA Astrophysics Data System (ADS)

    Momeni, Badri Z.; Fathi, Nastaran; Mohagheghi, Arezoo

    2015-01-01

    Dimethylplatinum(II) complexes [PtMe2(NN)] {NN = 4,4‧-Me2bpy (4,4‧-dimethyl-2,2‧-bipyridine); 5,5‧-Me2bpy (5,5‧-dimethyl-2,2‧-bipyridine)} were reacted with alkyl halides (RX = EtI, EtBr) to yield the organoplatinum(IV) complexes [PtMe2RX(NN)]. On the basis of NMR data, the platinum(IV) product of each reaction contains almost exclusively the trans isomer but small traces of the cis isomers are also observed. On the other hand, the reaction of [PtMe2(NN)] {NN = bu2bpy (4,4‧-di-tert-butyl-2,2‧-bipyridine); 4,4‧-Me2bpy; 5,5‧-Me2bpy} with CH2Br2 gave a mixture of cis and trans-[PtMe2(CH2Br)Br(NN)] formed by the oxidative addition of one of the C-Br bonds. The formation of the cis isomer increases in the order of 5,5‧-Me2bpy > bu2bpy > 4,4‧-Me2bpy. The reaction of [PtMe2(NN)] {NN = bpy (2,2‧-bipyridine), phen (1,10-phenanthroline)} with 1,8-dibromooctane or 1,9-dibromononane afforded the mononuclear complexes [PtMe2{(CH2)nBr}Br(NN)] (n = 8-9). The products were fully characterized by elemental analysis, 1H, 13C, HH COSY, HMQC, DEPT and DEPTQ-135 NMR spectroscopy. The crystal structure of [PtMe2EtI(4,4‧-Me2bpy)] reveals that Pt(IV) atom is six-coordinated in a slightly distorted octahedral geometry with the ethyl group trans to iodide.

  3. Towards Elucidating Carnosic Acid Biosynthesis in Lamiaceae: Functional Characterization of the Three First Steps of the Pathway in Salvia fruticosa and Rosmarinus officinalis

    PubMed Central

    Božić, Dragana; Papaefthimiou, Dimitra; Brückner, Kathleen; de Vos, Ric C. H.; Tsoleridis, Constantinos A.; Katsarou, Dimitra; Papanikolaou, Antigoni; Pateraki, Irini; Chatzopoulou, Fani M.; Dimitriadou, Eleni; Kostas, Stefanos; Manzano, David; Scheler, Ulschan; Ferrer, Albert; Tissier, Alain; Makris, Antonios M.; Kampranis, Sotirios C.; Kanellis, Angelos K.

    2015-01-01

    Carnosic acid (CA) is a phenolic diterpene with anti-tumour, anti-diabetic, antibacterial and neuroprotective properties that is produced by a number of species from several genera of the Lamiaceae family, including Salvia fruticosa (Cretan sage) and Rosmarinus officinalis (Rosemary). To elucidate CA biosynthesis, glandular trichome transcriptome data of S. fruticosa were mined for terpene synthase genes. Two putative diterpene synthase genes, namely SfCPS and SfKSL, showing similarities to copalyl diphosphate synthase and kaurene synthase-like genes, respectively, were isolated and functionally characterized. Recombinant expression in Escherichia coli followed by in vitro enzyme activity assays confirmed that SfCPS is a copalyl diphosphate synthase. Coupling of SfCPS with SfKSL, both in vitro and in yeast, resulted in the synthesis miltiradiene, as confirmed by 1D and 2D NMR analyses (1H, 13C, DEPT, COSY H-H, HMQC and HMBC). Coupled transient in vivo assays of SfCPS and SfKSL in Nicotiana benthamiana further confirmed production of miltiradiene in planta. To elucidate the subsequent biosynthetic step, RNA-Seq data of S. fruticosa and R. officinalis were searched for cytochrome P450 (CYP) encoding genes potentially involved in the synthesis of the first phenolic compound in the CA pathway, ferruginol. Three candidate genes were selected, SfFS, RoFS1 and RoFS2. Using yeast and N. benthamiana expression systems, all three where confirmed to be coding for ferruginol synthases, thus revealing the enzymatic activities responsible for the first three steps leading to CA in two Lamiaceae genera. PMID:26020634

  4. Synthesis of novel indole derivatives as promising DNA-binding agents and evaluation of antitumor and antitopoisomerase I activities.

    PubMed

    Lafayette, Elizabeth Almeida; de Almeida, Sinara Mônica Vitalino; Cavalcanti Santos, Renata Virginia; de Oliveira, Jamerson Ferreira; Amorim, Cezar Augusto da Cruz; da Silva, Rosali Maria Ferreira; Pitta, Maira Galdino da Rocha; Pitta, Ivan da Rocha; de Moura, Ricardo Olimpio; de Carvalho Júnior, Luiz Bezerra; de Melo Rêgo, Moacyr Jesus Barreto; de Lima, Maria do Carmo Alves

    2017-08-18

    Molecules bearing indole nucleus present diverse biological properties such as antitumor and anti-inflammatory activities that can be associated both to DNA and protein interactions. This study focused on the synthesis of new indole derivatives with thiazolidines and imidazolidine rings condensed as side chains as well as the evaluation of their ability to interact with the DNA and antitumor and topoisomerase inhibition activities. All derivatives were successfully synthesized and their structures were elucidated by mass spectrometry (MS), infrared (IR), spectroscopy (1)H NMR, (13)C NMR, COSY (1)H-(1)H and HSQC (1)H-(13)C. The antitumor activity was evaluated against different cancer cell lines using the antiproliferative MTT assay. DNA binding ability was analyzed by absorption spectroscopy and fluorescence technique using ethidium bromide (EB) as a fluorescent probe. Changes were observed in spectroscopic properties of the compounds after interacting with ctDNA (calf thymus DNA), with hypochromic and hyperchromic effects, besides blue or red shifts in the maxima of spectra. The indole derivative 5-(1H-Indol-3-ylmethylene)-thiazolidin-2,4-dione (4c) presented the best results in antitumor assay against the breast line tested (T47D), with IC50 value lower than the positive control, doxorubicin (1.93 and 4.61 μM, respectively). On the other hand, the compound 3-amino-5-(1H-indol-3-ylmethylene)-2-thioxo-thiazolidin-4-one (4a) was active against leukemia cell lines (HL60 and K562) with the high value of the DNA binding constant, Kb of 5.69 × 10(4). However, this compound (4a) did not inhibit the topoisomerase-I activity evaluated by relaxation assay. These results show that the indole nucleus contribute to the incorporation of molecules into the DNA. Moreover, it was highlighted that basic side chains, such as thiazolidines and imidazolidines, and free amino group, are relevant for design of promising antitumor and DNA binding compounds. Copyright © 2017

  5. Synthesis and study of the spectroscopic and redox properties of Ru(II),Pt(II) mixed-metal complexes bridged by 2,3,5,6-tetrakis(2-pyridyl)pyrazine.

    PubMed

    Zhao, Shengliang; Arachchige, Shamindri M; Slebodnick, Carla; Brewer, Karen J

    2008-07-21

    The mixed-metal supramolecular complexes [(tpy)Ru(tppz)PtCl](PF6)3 and [ClPt(tppz)Ru(tppz)PtCl](PF6)4 (tpy = 2,2':6',2''-terpyridine and tppz = 2,3,5,6-tetrakis(2-pyridyl)pyrazine) were synthesized and characterized. These complexes contain ruthenium bridged by tppz to platinum centers to form stereochemically defined linear assemblies. X-ray crystallographic determinations of the two complexes confirm the identity of the metal complexes and reveal intermolecular interactions of the Pt sites in the solid state for [(tpy)Ru(tppz)PtCl](PF6)3 with a Pt...Pt distance of 3.3218(5) A. The (1)H NMR spectra show the expected splitting patterns characteristic of stereochemically defined mixed-metal systems and are assigned with the use of (1)H-(1)H COSY and NOESY. Electronic absorption spectroscopy displays intense ligand-based pi --> pi* transitions in the UV and MLCT transitions in the visible. Electrochemically [(tpy)Ru(tppz)PtCl](PF6)3 and [ClPt(tppz)Ru(tppz)PtCl](PF6)4 display reversible Ru (II/III) couples at 1.63 and 1.83 V versus Ag/AgCl, respectively. The complexes display very low potential tppz (0/-) and tppz(-/2-) couples, relative to their monometallic synthons, [(tpy)Ru(tppz)](PF6)2 and [Ru(tppz)2](PF6)2, consistent with the bridging coordination of the tppz ligand. The Ru(dpi) --> tppz(pi*) MLCT transitions are also red-shifted relative to the monometallic synthons occurring in the visible centered at 530 and 538 nm in CH3CN for [(tpy)Ru(tppz)PtCl](PF6)3 and [ClPt(tppz)Ru(tppz)PtCl](PF6)4, respectively. The complex [(tpy)Ru(tppz)PtCl](PF6)3 displays a barely detectable emission from the Ru(dpi) --> tppz(pi*) (3)MLCT in CH 3CN solution at RT. In contrast, [ClPt(tppz)Ru(tppz)PtCl](PF6)4 displays an intense emission from the Ru(dpi) --> tppz(pi*) (3)MLCT state at RT with lambda max(em) = 754 nm and tau = 80 ns.

  6. New ursane triterpenoids from Ficus pandurata and their binding affinity for human cannabinoid and opioid receptors.

    PubMed

    Khedr, Amgad I M; Ibrahim, Sabrin R M; Mohamed, Gamal A; Ahmed, Hany E A; Ahmad, Amany S; Ramadan, Mahmoud A; El-Baky, Atef E Abd; Yamada, Koji; Ross, Samir A

    2016-07-01

    Phytochemical investigation of Ficus pandurata Hance (Moraceae) fruits has led to the isolation of two new triterpenoids, ficupanduratin A [1β-hydroxy-3β-acetoxy-11α-methoxy-urs-12-ene] (11) and ficupanduratin B [21α-hydroxy-3β-acetoxy-11α-methoxy-urs-12-ene] (17), along with 20 known compounds: α-amyrin acetate (1), α-amyrin (2), 3β-acetoxy-20-taraxasten-22-one (3), 3β-acetoxy-11α-methoxy-olean-12-ene (4), 3β-acetoxy-11α-methoxy-12-ursene (5), 11-oxo-α-amyrin acetate (6), 11-oxo-β-amyrin acetate (7), palmitic acid (8), stigmast-4,22-diene-3,6-dione (9), stigmast-4-ene-3,6-dione (10), stigmasterol (12), β-sitosterol (13), stigmast-22-ene-3,6-dione (14), stigmastane-3,6-dione (15), 3β,21β-dihydroxy-11α-methoxy-olean-12-ene (16), 3β-hydroxy-11α-methoxyurs-12-ene (18), 6-hydroxystigmast-4,22-diene-3-one (19), 6-hydroxystigmast-4-ene-3-one (20), 11α,21α-dihydroxy-3β-acetoxy-urs-12-ene (21), and β-sitosterol-3-O-β-D-glucopyranoside (22). Compound 21 is reported for the first time from a natural source. The structures of the 20 compounds were elucidated on the basis of IR, 1D ((1)H and (13)C), 2D ((1)H-(1)H COSY, HSQC, HMBC and NOESY) NMR and MS spectroscopic data, in addition to comparison with literature data. The isolated compounds were evaluated for their anti-microbial, anti-malarial, anti-leishmanial, and cytotoxic activities. In addition, their radioligand displacement affinity on opioid and cannabinoid receptors was assessed. Compounds 4, 11, and 15 exhibited good affinity towards the CB2 receptor, with displacement values of 69.7, 62.5 and 86.5 %, respectively. Furthermore, the binding mode of the active compounds in the active site of the CB2 cannabinoid receptors was investigated through molecular modelling.

  7. Oxidation of Pt-bound bis-hydroxylamine as a novel route to unexplored dinitrosoalkane ligated species.

    PubMed

    Luzyanin, Konstantin V; Gushchin, Pavel V; Pombeiro, Armando J L; Haukka, Matti; Ovcharenko, Victor I; Kukushkin, Vadim Yu

    2008-08-04

    The reaction of K 2[PtCl 4] and HO(H)NCMe 2CMe 2N(H)OH.H 2SO 4 ( BHA.H 2SO 4; 2) in a molar ratio 1:2 at 20-25 degrees C in water affords a mixture of [Pt(BHA) 2][PtCl 4] ( 5) and [Pt(BHA-H) 2] ( 6) ( BHA- H = anionic monodeprotonated form of BHA) which, upon heating at 80-85 degrees C for 12 h or on prolonged keeping at 20-25 degrees C for 2 weeks, is subject to a slow transformation giving [PtCl 2(BHA)] ( 7). The latter compound is also obtained from the reaction between K[PtCl 3(Me 2 SO)] and 2. The chlorination of [PtCl 2(BHA)] ( 7) in freshly distilled dry chloroform leads to the selective oxidation of one N(H)OH group yielding [PtCl 2{HO(H) NCMe 2CMe 2 N=O}] ( 13), while the chlorination in water produces the complex [PtCl 2(O= NCMe 2CMe 2 N=O)] ( 14) bearing the unexplored dinitrosoalkane species. Treatment of 14 with 2 equiv of 1,2-bis-(diphenylphosphino)ethane (dppe) in CH 2Cl 2 results in the liberation of the dinitrosoalkane ligand followed by its fast cyclization giving the alpha-dinitrone (3,3,4,4-tetramethyl-1,2-diazete-1,2-dioxide) in solution and the solid [Pt(dppe) 2](Cl) 2. The Pt (II) complexes with hydroxylamino ( intersection)oximes [PtCl 2{HO(H) NC(Me) 2C(R)= NOH}] (R = Me 8; R = Ph 9) upon their oxidation with Cl 2 in CHCl 3 afford the nitrosoalkane derivatives [PtCl 2{O= NCMe 2C(R)= NOH}] (R = Me 16; Ph 17), respectively, while the corresponding chlorination of the bis-chelates [Pt{HO(H) NCMe 2C(R)= NOH} 2] (R = Me 10; Ph 11) gives [Pt{O= NCMe 2C(R)= NO} 2] (R = Me 18; Ph 19). The formulation of 5- 19 is based on C, H, and N microanalyses, IR, 1D ( (1)H, (13)C{ (1)H}, (195)Pt) and 2D ( (1)H, (1)H-COSY, (1)H, (13)C-HSQC) NMR spectroscopies, and X-ray diffraction for five complexes ( 5, 7, and 12- 14).

  8. Cyclic dipeptides from rhabditid entomopathogenic nematode-associated Bacillus cereus have antimicrobial activities.

    PubMed

    Nishanth Kumar, S; Nath, Vishnu Sukumari; Pratap Chandran, R; Nambisan, Bala

    2014-02-01

    The cell free culture filtrate of Bacillus cereus associated with an entomopathogenic nematode, Rhabditis (Oscheius) sp. exhibited strong antimicrobial activity. The ethyl acetate extract of the bacterial culture filtrate was purified by silica gel column chromatography to obtain four bioactive compounds. The structure and absolute stereochemistry of these compounds were determined based on extensive spectroscopic analyses (FABMS, (1)H NMR, (13)C NMR, (1)H-(1)H COSY, (1)H-(13)C HMBC) and Marfey's method. The compounds were identified as cyclic dipeptides (CDPs): cyclo(L-Pro-L-Trp), cyclo(L-Leu-L-Val), cyclo(D-Pro-D-Met), and cyclo(D-Pro-D-Phe), respectively. Compounds recorded significant antibacterial activity against all the test bacteria (Staphylococcus epidermidis, Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa and methicillin-resistant S. aureus) except cyclo(L-Leu-L-Val). Cyclo(L-Leu-L-Val) recorded activity only against Gram positive bacteria. Best antibacterial activity was recorded by cyclo(L-Pro-L-Trp) against S. aureus (4 μg/ml). The four compounds were active against all the five fungi tested (Trichophyton rubrum, Aspergillus flavus, Candida albicans, Candida tropicalis and Cryptococcus neoformans) and the activity was compared with amphotericin B, the standard fungicide. The highest activity of 1 μg/ml by cyclo(L-Pro-L-Trp) was recorded against T. rubrum, a human pathogen responsible for causing athlete's foot, jock itch, and ringworm. The activity of cyclo(L-Pro-L-Trp) against T. rubrum, C. neoformans and C. albicans were better than amphotericin B, the standard antifungal agent. To our knowledge, this is the first report of antifungal activity of CDPs against the human pathogenic fungi T. rubrum and C. neoformans. The four CDPs are nontoxic to healthy human cell line up to 200 μg/ml. We conclude that the bacterium associated with entomopathogenic nematode is promising sources of natural antimicrobial

  9. Pharmacological evaluation of the semi-purified fractions from the soft coral Eunicella singularis and isolation of pure compounds.

    PubMed

    Deghrigue, Monia; Festa, Carmen; Ghribi, Lotfi; D'auria, Maria Valeria; de Marino, Simona; Ben Jannet, Hichem; Ben Said, Rafik; Bouraoui, Abderrahman

    2014-09-10

    Gorgonians of the genus Eunicella are known for possessing a wide range of pharmacological activities such as antiproliferative and antibacterial effect. The aim of this study was to evaluate the anti-inflammatory and gastroprotective effect of the organic extract and its semi-purified fractions from the white gorgonian Eunicella singularis and the isolation and identification of pure compound(s) from the more effective fraction. Anti-inflammatory activity was evaluated, using the carrageenan-induced rat paw edema test and in comparison to the reference drug Acetylsalicylate of Lysine. The gastroprotective activity was determined using HCl/EtOH induced gastric ulcers in rats. The purification of compound(s) from the more effective fraction was done by two chromatographic methods (HPLC and MPLC). The structure elucidation was determined by extensive spectroscopic analysis (1H and 13C NMR, COSY, HMBC, HMQC and NOESY) and by comparison with data reported in the literature. The evaluation of the anti-inflammatory activity of different fractions from Eunicella singularis showed in a dependent dose manner an important anti-inflammatory activity of the ethanol fraction, the percentage of inhibition of edema, 3 h after carrageenan injection was 66.12%, more effective than the reference drug (56.32%). In addition, this ethanolic fraction showed an interesting gastroprotective effect compared to the reference drugs, ranitidine and omeprazol. The percentage of inhibition of gastric ulcer induced by HCl/ethanol in rats was 70.27%. The percentage of the reference drugs (ranitidine and omeprazol) were 65 and 87.53%, respectively. The purification and structure elucidation of compound(s) from this ethanolic fraction were leading to the isolation of five sterols: cholesterol (5α-cholest-5-en-3β-ol) (1); ergosterol (ergosta-5,22-dien-3β-ol) (2); stigmasterol (24-ethylcholesta-5,22-dien-3b-ol) (3); 5α,8α-epidioxyergosta 6,22-dien-3β-ol (4) and 3β-hydroxy-5α,8

  10. Trigonal-bipyramidal tin(IV) complexes containing tetradentate tripodal tristhiolatophosphine ligands: synthesis, characterization, crystal structure, and transmetalation reactions.

    PubMed

    Clark, Kerry A Fusie; George, T Adrian

    2005-01-24

    The reactions of the lithium salts of the proligands P(C(6)H(4)-2-SH)(3) (P((H)SH)(3)), P(C(6)H(3)-3-SiMe(3)-2-SH)(3) (P((TMS)SH)(3)), and P(C(6)H(3)-5-Me-2-SH)(3) (P((Me)SH)(3)) with RSnCl(3) (R = Ph, Me, n-Bu), in THF at 0 degrees C, produced a series of trigonal-bipyramidal complexes of the type RSn(PS(3)). The crystal structures of PhSn(P(H)S(3)), PhSn(P(TMS)S(3)), and PhSn(P(Me)S(3)) reveal considerable distortion from local C(3v) symmetry for the Sn(PS(3)) group. Unique to PhSn(P(Me)S(3)) is the presence of intramolecular hydrogen bonding between one sulfur atom and an ortho H atom of the Ph group, creating a plane that includes this S atom and the corresponding C(6)H(3) ring, a phosphorus atom, and the PhSn group. An analysis of the (1)H, (13)C, and (31)P NMR data from a combination of HMQC, HMBC, 2-D COSY, and (1)H{(31)P} NMR studies reveals that in solution the Sn(PS(3)) groups exhibit local C(3v) symmetry, even at low temperature. Byproducts frequently found in the synthesis of the proligands and tin complexes, and subsequent reactions, result from the oxidation of the trianionic tristhiolatophosphine ligand. The crystal structure of one of these, [OP((H)S(3))](2), shows that the molecule contains two ligands joined by a S-S bond. Within each original ligand the remaining two sulfur atoms form a S-S bond, and each phosphorus atom is oxidized. PhSn(P(TMS)S(3)) reacted with 2 equiv of FeCl(3) in CH(2)Cl(2) to produce the iron(IV) complex FeCl(P(TMS)S(3)). FeCl(P(TMS)S(3)) decomposed in the presence of excess FeCl(3). Similar transmetalation reactions with FeCl(2) or [Fe(2)OCl(6)](2)(-) required the addition of ferrocenium ion to complete the oxidation of iron to 4+. RuCl(P(TMS)S(3)) was prepared by the reaction between PhSn(P(TMS)S(3)) and RuCl(2)(DMSO)(4) without the addition of an external oxidizing agent.

  11. Solution behavior and complete sup 1 H and sup 13 C NMR assignments of the coenzyme B sub 12 derivative (5 prime -deoxyadenosyl)cobinamide using modern 2D NMR experiments, including 600-MHz sup 1 H NMR data

    SciTech Connect

    Pagano, T.G.; Yohannes, P.G.; Marzilli, L.G. ); Hay, B.P.; Scott, J.R.; Finke, R.G. )

    1989-02-15

    Two-dimensional (2D) NMR methods have been used to assign completely the {sup 1}H and {sup 13}C NMR spectra of the (5{prime}-deoxyadenosyl)cobinamide cation (AdoCbi{sup +}) in D{sub 2}O. Most of the {sup 1}H spectral assignments were made by using 2D homonuclear shift correlation spectroscopy (COSY), homonuclear Hartmann-Hahn spectroscopy (HOHAHA), absorption-mode (phase sensitive) 2D nuclear Overhauser effect (NOE) spectroscopy, and spin-locked NOE spectroscopy (also called ROESY, for rotating-frame Overhauser enhancement spectroscopy). Most of the protonated carbon resonances were assigned by using {sup 1}H-detected heteronuclear multiple-quantum coherence (HMQC) spectroscopy. The nonprotonated carbon resonances, as well as the remaining unassigned {sup 1}H and {sup 13}C NMR signals, were assigned from long-range {sup 1}H-{sup 13}C connectivities determined from {sup 1}H-detected multiple-bond heteronuclear multiple-quantum coherence spectroscopy (HMBC). Comparison of the {sup 13}C chemical shifts and {sup 1}H NOEs of AdoCbi{sup +} with those of coenzyme B{sup 12} ((5{prime}-deoxyadenosyl)cobalamin) and its benzimidazole-protonated, base-off form indicates that the electronic properties and structure of AdoCbi{sup +} are similar to that of coenzyme B{sup 12} in the protonated, base-off form. The {sup 13}C chemical shifts of most of the carbons of AdoCbi{sup +} do not vary significantly from those of base-off, benzimidazole-protonated coenzyme B{sup 12}, indicating that the electronic environment of the corrin ring is also similar in both compounds. However, significant differences in the chemical shifts of some of the corresponding carbons of the b, d, e, and f corrin side chains in AdoCbi{sup +} and in base-off, benzimidazole-protonated coenzyme B{sub 12} indicate that the positions of these side chains may be different in AdoCbi{sup +} compared to base-off coenzyme B{sup 12}.

  12. Neuroprotective Properties of Compounds Extracted from Dianthus superbus L. against Glutamate-induced Cell Death in HT22 Cells

    PubMed Central

    Yun, Bo-Ra; Yang, Hye Jin; Weon, Jin Bae; Lee, Jiwoo; Eom, Min Rye; Ma, Choong Je

    2016-01-01

    -methoxy-4-hydroxyphenylethanol (8), hydroferulic acid (9), and methyl hydroferulate (10) were isolated from D. superbus extract4-hydroxy-benzeneacetic acid and 4-methoxybenzeneacetic acid showed significant protective activity against glutamate-induced toxicity in HT22 cells. Abbreviations used: CNS: Central nervous system, ROS: Reactive oxygen species, CHCl3: Chloroform, EtOAc: Ethyl acetate, BuOH: Butanol, HPLC: High performance liquid chromatography, TLC: Thin layer chromatography, MPLC: Middle performance liquid chromatography, MeOH: Methanol, OD: Optical density, COSY: Correlation spectroscopy, HMQC: Heteronuclear multiple-quantum correlation, HMBC: Heteronuclear multiple-bond correlation, HR-MS: High-resolution molecular spectroscopy, MTT: 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide. PMID:27076746

  13. Anti-inflammatory activity of a new cyclic peptide, citrusin XI, isolated from the fruits of Citrus unshiu.

    PubMed

    Noh, Hyung Jun; Hwang, Dukhyun; Lee, Eun Suk; Hyun, Jae Wook; Yi, Pyoung Ho; Kim, Geum Soog; Lee, Seung Eun; Pang, Changhyun; Park, Yong Joo; Chung, Kyu Hyuck; Kim, Gun Do; Kim, Ki Hyun

    2015-04-02

    Citrus unshiu (Rutaceae) is an easy-peeling citrus fruit, which has been used as a traditional Korean medicine for improving skin elasticity, relieving fatigue and cough, and preventing bronchitis, flu, and various cancers. However, its active components associated with anti-inflammation and underlying mechanisms remain unknown. In this study, we investigated the active constituents from the fruits of Citrus unshiu and evaluated the anti-inflammatory activity in order to support the traditional usage of Citrus unshiu. Repeated column chromatography, together with a semi-preparative HPLC purification was used to separate the bioactive constituent from the EtOAc soluble fraction of the EtOH extract of Citrus unshiu fruits. Anti-inflammatory effects of the isolated compounds on lipopolysaccharide (LPS)-induced production of pro-inflammatory mediators were examined using RAW264.7 macrophage cells. A new cyclic peptide, citrusin XI (1), was isolated and identified from the fruits of Citrus unshiu. The structure of compound 1 was elucidated by spectroscopic analysis, including 1D and 2D nuclear magnetic resonance (NMR) ((1)H, (13)C, COSY, HMQC and HMBC experiments), and high resolution (HR)-mass spectrometry, and its absolute configurations were further confirmed by the Marfey׳s method. Compound 1 decreased NO production in LPS-stimulated RAW264.7 cells in a dose-dependent manner with an IC50 value of 70μM. Compound 1 suppressed NO production by decreasing iNOS expression but COX-2 expression was slightly associated with the reduction by compound 1 in LPS-induced RAW264.7 cells. Furthermore, compound 1 inhibited NF-κB activation by blocking IκBα degradation and NF-κB phosphorylation in LPS-stimulated RAW264.7 cells. These results indicate that a new cyclic peptide, citrusin XI, from Citrus unshiu fruits has anti-inflammatory properties that inhibit the release of pro-inflammatory mediators. Compound 1 decreases NO production by decreasing iNOS expression and NF

  14. Lanthanide complexes of chiral 3 + 3 macrocycles derived from (1R,2R)-1,2-diaminocyclohexane and 2,6-diformyl-4-methylphenol.

    PubMed

    Paluch, Marta; Lisowski, Jerzy; Lis, Tadeusz

    2006-01-14

    The enantiopure amine macrocycle H(3)L, as well as the parent macrocyclic Schiff base H(3)L1, the 3 + 3 condensation product of (1R,2R)-1,2-diaminocyclohexane and 2,6-diformyl-4-methylphenol, are able to form mononuclear complexes with lanthanide(III) ions. The lanthanide(III) complexes of H(3)L have been studied in solution using NMR spectroscopy and electrospray mass spectrometry. The NMR spectra indicate the presence of complexes of low C(1) and C(2) symmetry. The (1)H and (13)C NMR signals of the Lu(III) complex obtained from H(3)L have been assigned on the basis of COSY, TOCSY, NOESY, ROESY and HMQC spectra. The NMR data reveal unsymmetrical binding of lanthanide(III) ion and the presence of a dynamic process corresponding to rotation of Lu(III) within the macrocycle. The [Ln(H(4)L)(NO(3))(2)](NO(3))(2)(Ln = Sm(III), Eu(III), Dy(III), Yb(III) and Lu(III)) complexes of the cationic ligand H(4)L(+) have been isolated in pure form. The X-ray analysis of the [Eu(H(4)L)(NO(3))(2)](NO(3))(2) complex confirms the coordination mode of the macrocycle determined on the basis of NMR results. In this complex the europium(III) ion is bound to three phenolate oxygen atoms and two amine nitrogen atoms of the monoprotonated macrocycle H(4)L(+), as well as to two axial bidendate nitrate anions. In the presence of a base, mononuclear La(III), Ce(III) and Pr(III) complexes of the deprotonated form of the ligand L(3-) can be obtained. When 2 equivalents of Pr(III) are used in this synthesis Na(3)[Pr(2)L(NO(3))(2)(OH)(2)](2)NO(3).5H(2)O is obtained. The NMR, ES MS and an X-ray crystal model of this complex show coordination of two Pr(III) ions by the macrocycle L. The X-ray crystal structure of the free macrocycle H(3)L1 has also been determined. In contrast to macrocyclic amine H(3)L, the Schiff base H(3)L1 adopts a cone-type conformation resembling calixarenes.

  15. Enantiomeric self-recognition in homo- and heterodinuclear macrocyclic lanthanide(III) complexes.

    PubMed

    Lisowski, Jerzy

    2011-06-20

    The controlled formation of lanthanide(III) dinuclear μ-hydroxo-bridged [Ln(2)L(2)(μ-OH)(2)X(2)](n+) complexes (where X = H(2)O, NO(3)(-), or Cl(-)) of the enantiopure chiral macrocycle L is reported. The (1)H and (13)C NMR resonances of these complexes have been assigned on the basis of COSY, NOESY, TOCSY, and HMQC spectra. The observed NOE connectivities confirm that the dimeric solid-state structure is retained in solution. The enantiomeric nature of the obtained chiral complexes and binding of hydroxide anions are reflected in their CD spectra. The formation of the dimeric complexes is accompanied by a complete enantiomeric self-recognition of the chiral macrocyclic units. The reaction of NaOH with a mixture of two different mononuclear lanthanide(III) complexes, [Ln(1)L](3+) and [Ln(2)L](3+), results in formation of the heterodinuclear [Ln(1)Ln(2)L(2)(μ-OH)(2)X(2)](n+) complexes as well as the corresponding homodinuclear complexes. The formation of the heterodinuclear complex is directly confirmed by the NOESY spectra of [EuLuL(2)(μ-OH)(2)(H(2)O)(2)](4+), which reveal close contacts between the macrocyclic unit containing the Eu(III) ion and the macrocyclic unit containing the Lu(III) ion. While the relative amounts of homo- and heterodinuclear complexes are statistical for the two lanthanide(III) ions of similar radii, a clear preference for the formation of heterodinuclear species is observed when the two mononuclear complexes contain lanthanide(III) ions of markedly different sizes, e.g., La(III) and Yb(III). The formation of heterodinuclear complexes is accompanied by the self-sorting of the chiral macrocyclic units based on their chirality. The reactions of NaOH with a pair of homochiral or racemic mononuclear complexes, [Ln(1)L(RRRR)](3+)/[Ln(2)L(RRRR)](3+), [Ln(1)L(SSSS)](3+)/[Ln(2)L(SSSS)](3+), or [Ln(1)L(rac)](3+)/[Ln(2)L(rac)](3+), results in mixtures of homochiral, homodinuclear and homochiral, heterodinuclear complexes. On the contrary, no

  16. 4-Methylthio-butanyl derivatives from the seeds of Raphanus sativus and their biological evaluation on anti-inflammatory and antitumor activities.

    PubMed

    Kim, Ki Hyun; Moon, Eunjung; Kim, Sun Yeou; Choi, Sang Un; Lee, Jei Hyun; Lee, Kang Ro

    2014-01-01

    Raphanus sativus seeds (Brassicaceae) known as Raphani Semen have long been used as anti-cancer and/or anti-inflammatory agents in Korean traditional medicine. This study was designed to isolate the bioactive constituents from the seed extracts of Raphanus sativus and evaluate their anti-inflammatory and antitumor activities. Bioassay-guided fractionation and chemical investigation of a methanolic extract of the seeds of Raphanus sativus led to the isolation and identification of seven 4-methylthio-butanyl derivatives. Structural elucidation of the isolated compounds was carried out using 1D and 2D nuclear magnetic resonance (NMR) spectroscopy techniques ((1)H, (13)C, COSY, HMQC and HMBC experiments) and mass spectrometry. The isolated compounds were characterized as in the following: three new 4-methylthio-butanyl derivatives, sinapoyl desulfoglucoraphenin (1), (E)-5-(methylsulfinyl)pent-4-enoxylimidic acid methyl ester (2), and (S)-5-((methylsulfinyl)methyl)pyrrolidine-2-thione (3), together with four known compounds, 5-(methylsulfinyl)-4-pentenenitrile (4), 5-(methylsulfinyl)-pentanenitrile (5), sulforaphene (6), and sulforaphane (7). Full NMR data assignments of the three known compounds 4-6 were also reported for the first time. We evaluated the anti-neuroinflammatory effect of 1-7 in lipopolysaccharide-stimulated murine microglia BV2 cells. Compound 1 significantly inhibited nitrite oxide production with IC50 values of 45.36 μM. Moreover, it also reduced the protein expression of inducible nitric oxide synthase. All isolates were also evaluated for their antiproliferative activities against four human tumor cell lines (A549, SK-OV-3, SK-MEL-2, and HCT-15), and all of them showed antiproliferative activity against the HCT-15 cell, with IC50 values of 8.49-23.97 μM. 4-Methylthio-butanyl derivatives were one of the main compositions of Raphanus sativus seeds, and activities demonstrated by the isolated compounds support the ethnopharmacological use of Raphanus

  17. Variecolactol: A New Sesterterpene Lactone from the Sclerotia of Aspergillus auricomus (Guegen) Saito

    USDA-ARS?s Scientific Manuscript database

    Variecolactol (1), a new sesterterpene lactone related to variecolin (2), has been isolated from the organic extracts of Aspergillus auricomus. Structure determination of this compound was achieved primarily through HMQC, HMBC, and NOESY experiments. The known compounds dihydropenicillic acid (3) ...

  18. 1H Photo-CIDNP Enhancements in Heteronuclear Correlation NMR Spectroscopy

    PubMed Central

    Sekhar, Ashok; Cavagnero, Silvia

    2009-01-01

    Photochemically induced dynamic nuclear polarization (photo-CIDNP) is usually employed as a probe of solvent exposure, in biomolecular NMR. The potential of the photo-CIDNP effect for sensitivity enhancement, however, remains poorly explored. Here, we introduce 1H-photo-CIDNP in heteronuclear correlation spectroscopy at low laser irradiation power (1 W), and compare the sensitivity of various 1H-Photo-CIDNP-enhanced- (HPE) 1H◻15N heteronuclear correlation pulse sequences, including HSQC, HMQC, and SOFAST-HMQC, in terms of their ability to detect the Trp indole Hε1 resonance. Both Trp and the Trp-containing protein apoHmpH were analyzed using flavin mononucleotide as photosensitizer in aqueous solutions either containing or lacking urea. We find that 1H◻15N photo-CIDNP-SOFAST-HMQC, denoted here as HPE-SOFAST-HMQC, yields a two-fold higher signal-to-noise per unit time than the parent SOFAST-HMQC for the solvent-exposed Trp of urea-unfolded apoHmpH. Thus, HPE-SOFAST-HMQC is the most sensitive heteronuclear correlation pulse sequence for the detection of solvent-exposed Trp. PMID:19462951

  19. The quantitation of nuclear Overhauser effect methods for total conformational analysis of peptides in solution. Application to gramicidin S.

    PubMed Central

    Jones, C R; Sikakana, C T; Hehir, S; Kuo, M C; Gibbons, W A

    1978-01-01

    The [1H:1H] nuclear Overhauser effects (NOE's) and spin-lattice relaxation times (T1's) are reported for the backbone protons of the decapeptide gramicidin S. Several methods for calculating interproton distances from these measurements are presented. Ratios of interproton distances were obtained from [1H:1H] NOE's and from the combination of [1H:1H]NOE'S and T1 values. Actual proton-proton distances were calculated from these ratios either by using the known distance between two geminal protons or distances derived from scalar coupling constants. The interproton distances calculated for gramicidin S are consistent with a II' beta-turn/antiparallel beta-sheet conformation. PMID:83886

  20. Proton-detected 3D (1)H/(13)C/(1)H correlation experiment for structural analysis in rigid solids under ultrafast-MAS above 60 kHz.

    PubMed

    Zhang, Rongchun; Nishiyama, Yusuke; Ramamoorthy, Ayyalusamy

    2015-10-28

    A proton-detected 3D (1)H/(13)C/(1)H chemical shift correlation experiment is proposed for the assignment of chemical shift resonances, identification of (13)C-(1)H connectivities, and proximities of (13)C-(1)H and (1)H-(1)H nuclei under ultrafast magic-angle-spinning (ultrafast-MAS) conditions. Ultrafast-MAS is used to suppress all anisotropic interactions including (1)H-(1)H dipolar couplings, while the finite-pulse radio frequency driven dipolar recoupling (fp-RFDR) pulse sequence is used to recouple dipolar couplings among protons and the insensitive nuclei enhanced by polarization transfer technique is used to transfer magnetization between heteronuclear spins. The 3D experiment eliminates signals from non-carbon-bonded protons and non-proton-bonded carbons to enhance spectral resolution. The 2D (F1/F3) (1)H/(1)H and 2D (13)C/(1)H (F2/F3) chemical shift correlation spectra extracted from the 3D spectrum enable the identification of (1)H-(1)H proximity and (13)C-(1)H connectivity. In addition, the 2D (F1/F2) (1)H/(13)C chemical shift correlation spectrum, incorporated with proton magnetization exchange via the fp-RFDR recoupling of (1)H-(1)H dipolar couplings, enables the measurement of proximities between (13)C and even the remote non-carbon-bonded protons. The 3D experiment also gives three-spin proximities of (1)H-(1)H-(13)C chains. Experimental results obtained from powder samples of L-alanine and L-histidine ⋅ H2O ⋅ HCl demonstrate the efficiency of the 3D experiment.