We report extension of the D-FW analysis using referenced (2)H DOSY. This technique was developed in response to limitations due to peak overlay in (1)H DOSY spectra. We find a corresponding linear relationship (R(2) > 0.99) between log D and log FW as the basis of the D-FW analysis. The solution-state structure of THF solvated lithium diisopropyl amide (LDA) in hydrocarbon solvent was chosen to demonstrate the reliability of the methodology. We observe an equilibrium between monosolvated and disolvated dimeric LDA complexes at room temperature. Additionally we demonstrate the application of the (2)H D-FW analysis using a compound with an exchangeable proton that is readily labeled with (2)H. Hence, the (2)H DOSY D-FW analysis is shown to provide results consistent with the (1)H DOSY method, thereby greatly extending the applicability of the D-FW analysis.
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http://dx.doi.org/10.1021/acs.joc.5b01457 | DOI Listing |
Medicine (Baltimore)
December 2015
From the Department of Nutrition, Aerospace Center Hospital (M-YX, JY); School of Public Health, Peking University (BC, D-FW, Q-BL); Department of Ultrasound (J-HG); Department of Respiratory, Aerospace Center Hospital (K-LC); and Department of Clinical Nutrition, China-Japan Friendship Hospital, Beijing, P.R. China (MS).
Human adenovirus 36 (HAdV-36), as the key pathogen, was supposed and discussed to be associated with obesity. We searched the references on the association between HAdV-36 infection and obesity with the different epidemiological methods, to explore the relationship with a larger sample size by meta-analysis and compare the differences of epidemiological methods and population subsets by the subgroup analyses.We conducted literature search on the association between HAdV-36 infections and obesity in English or Chinese published up to July 1, 2015.
View Article and Find Full Text PDFMedicine (Baltimore)
September 2015
From the School of Public Health, Peking University, Beijing, P.R. China (D-FW, BC, Y-QL, L-LY, RL, J-YW, Q-BL); and Department of Nutrition, Aerospace Center Hospital, Beijing, P.R. China (M-YX).
Schizophrenia is a complex and disabling psychiatric disorder, and tardive dyskinesia (TD) is a severe adverse drug effect occurring in 20% to 40% of schizophrenic patients chronically treated with typical neuroleptics. Previous studies suggested that the manganese superoxide dismutase (MnSOD) activity was associated with the development of schizophrenia. Ala-9Val polymorphism, a functional polymorphism of MnSOD gene, has been reported to be related to the risk of schizophrenia and TD.
View Article and Find Full Text PDFJ Org Chem
September 2015
Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States.
We report extension of the D-FW analysis using referenced (2)H DOSY. This technique was developed in response to limitations due to peak overlay in (1)H DOSY spectra. We find a corresponding linear relationship (R(2) > 0.
View Article and Find Full Text PDFJ Am Chem Soc
June 2015
Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States.
We report the crystal structure of a substoichiometric, HMPA-trisolvated lithium pinacolone enolate tetramer (LiOPin)4·HMPA3 abbreviated as T3. In this tetramer one HMPA binds to lithium more strongly than the other two causing a reduction in spatial symmetry with corresponding loss of C3 symmetry. A variety of NMR experiments, including HMPA titration, diffusion coefficient-formula weight (D-FW) analysis, and other multinuclear one- and two-dimensional NMR techniques reveal that T3 is the major species in hydrocarbon solution when more than 0.
View Article and Find Full Text PDFJ Org Chem
December 2013
Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States.
We report the development of isotopic-labeled (13)C diffusion-ordered NMR spectroscopy (DOSY) NMR with diffusion coefficient-formula weight (D-FW) analysis and its application in characterizing the aggregation state of methyllithium aggregates and complexes with several widely used diamines. Commercially available (13)C-labeled benzene and several easily synthesized (13)C-labeled compounds using (13)C-labeled iodomethane as the isotopic source are developed as internal references for diffusion-formula weight analysis (D-FW). The technique greatly expands the applicability of DOSY D-FW analysis to a much wider variety of compounds because of isotopic labeling.
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