The Experts below are selected from a list of 60 Experts worldwide ranked by ideXlab platform

Scott D Bohle - One of the best experts on this subject based on the ideXlab platform.

Kristopher A Rosadiuk - One of the best experts on this subject based on the ideXlab platform.

Sachiko Hirota - One of the best experts on this subject based on the ideXlab platform.

  • chlorogenic acid in coffee can prevent the formation of Dinitrogen Trioxide by scavenging nitrogen dioxide generated in the human oral cavity
    Journal of Agricultural and Food Chemistry, 2007
    Co-Authors: Umeo Takahama, Kanako Ryu, Sachiko Hirota
    Abstract:

    Coffee contains antioxidants like chlorogenic acid and its isomers. In this report, effects of coffee on the nitrite-induced N2O3 formation were studied using whole saliva and bacterial fraction prepared from the saliva. The formation of N2O3 was measured by fluorescence increase due to the transformation of 4,5-diaminofluorescein to triazolfluorescein. Coffee inhibited the nitrite-induced fluorescence increase, and 50% inhibition was observed at several µg of coffee/mL in bacterial fraction of saliva as well as whole saliva. During the inhibition of the fluorescence increase, concentration of chlorogenic acid and its isomers decreased. It is discussed that the reduction of NO2 by chlorogenic acid and its isomers contributed to the coffee-dependent inhibition of the fluorescence increase as N2O3 is formed from NO and NO2. When coffee was added to whole saliva, chlorogenic acid and its isomers bound to cells in the saliva. The rate of the fluorescence increase in bacterial fraction, which was prepared at d...

Elaine A Moore - One of the best experts on this subject based on the ideXlab platform.

  • absolute shielding in Dinitrogen Trioxide recalculation of the shielding tensors
    Chemical Physics Letters, 2000
    Co-Authors: Elaine A Moore
    Abstract:

    Abstract A reanalysis of the absolute shielding tensors for the two nitrogens in N 2 O 3 is made using results from recent calculations to fix the out-of-plane component of the tensor. The recalculated experimental values and theoretical values from density functional and multi-configurational methods are now in good agreement for the nitro nitrogen. Agreement for the nitroso nitrogen is not so good and suggests that multiconfigurational calculations with larger basis sets are required. Remeasurement of the microwave spectrum with greater resolution of the spin–rotation fine structure is needed to provide good experimental values for the absolute shielding tensor elements. Measurement of the 15 N NMR spectrum of N 2 O 3 would also be useful to obtain a more accurate value of the 15 N chemical shifts.

Xuefeng Wang - One of the best experts on this subject based on the ideXlab platform.

  • a new conformer of Dinitrogen Trioxide in low temperature matrix trans cis n2o3
    Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 1998
    Co-Authors: Xuefeng Wang, Qizong Qin
    Abstract:

    Abstract Matrix isolated FTIR spectroscopy has been applied to investigate the N2O3 conformers in low temperature matrix. Irradiation of an argon matrix containing NO and NO2 with a pulsed laser at 355 nm causes the enhancement of a new set of vibrational bands, which results from the conversion of asym-N2O3 to a new conformer, trans–cis N2O3. The observed vibrational frequencies and relative intensities of the conformer are in good agreement with density functional theory (DFT) calculations at BLYP/6-31G* level. Upon annealing, the thermally induced conversion of the trans–cis N2O3 into sym-N2O3 takes place in argon matrix. Properties of trans–cis N2O3 conformer are determined for the first time.

  • ab initio study on the structure and vibrational spectra of Dinitrogen Trioxide and its isomers
    Journal of Molecular Structure, 1997
    Co-Authors: Xuefeng Wang, Qike Zheng, Kangnian Fan
    Abstract:

    Abstract Equilibrium geometries, dipole moments, harmonic vibrational frequencies, and IR intensities have been calculated for a set of Dinitrogen Trioxide conformers by ab initio calculations at the MP2 level with the 6-31G∗ and 6-311G∗ basis sets. The calculation results satisfactorily reproduce the experimental structural and vibrational spectral features of asym-N2O3 and sym-N2O3. Calculations at the same levels indicate that the trans-cis N2O3 is also a stable conformer of N2O3, and previously observed matrix IR spectral features that were not properly assigned should be attributed to the trans-cis structure of Dinitrogen Trioxide. However, our results show that the other two estimated conformers, Cs-N2O3 and cis-cis N2O3, are considered to be transition states.