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Volumn 130, Issue 36, 2008, Pages 11892-11900

13C-labeled N-acetyl-neuraminic acid in aqueous solution: Detection and quantification of acyclic keto, keto hydrate, and enol forms by 13C NMR spectroscopy

Author keywords

[No Author keywords available]

Indexed keywords

AQUEOUS SOLUTIONS;

EID: 51749096888     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja077565g     Document Type: Article
Times cited : (42)

References (45)
  • 12
    • 51749104198 scopus 로고    scopus 로고
    • Frisch, M. J.; et al. Gaussian03, Revision A.1; Gaussian, Inc., Pittsburgh, PA, 2003.
    • Frisch, M. J.; et al. Gaussian03, Revision A.1; Gaussian, Inc., Pittsburgh, PA, 2003.
  • 20
    • 0028300935 scopus 로고    scopus 로고
    • 13C NMR spectra of 1 at pH 2 were referenced in this fashion.
    • 13C NMR spectra of 1 at pH 2 were referenced in this fashion.
  • 21
    • 33847089740 scopus 로고    scopus 로고
    • C1,H3eq couplings: Czarniecki, M.; Thornton, E. R. J. Am. Chem. Soc. 1977, 99, 8273-8279;
    • C1,H3eq couplings: Czarniecki, M.; Thornton, E. R. J. Am. Chem. Soc. 1977, 99, 8273-8279;
  • 25
    • 0008954014 scopus 로고
    • de Mayo, P, Ed, Interscience Publishers: New York
    • Lemieux, R. U. In Molecular Rearrangements; de Mayo, P., Ed.; Interscience Publishers: New York, 1964; p 709.
    • (1964) Molecular Rearrangements , pp. 709
    • Lemieux, R.U.1
  • 33
    • 0001434616 scopus 로고    scopus 로고
    • 1H NMR data showed significantly different (absolute) 2JC2,H3ax and 2J C2,H3eq values in 1αp (7.7 and 4.3 Hz, respectively, whereas nearly identical couplings were observed in 1βp (∼3.6 Hz, As reported previously for 3JC1,H3ax and 3J C1,H3eq (Hori, H, Nakajima, T, Nishida, Y, Ohrui, H, Meguro, H. Tetrahedron Lett. 1988, 29, 6317-6320, 2JC2,H3ax and 2J C2,H3eq can be used to distinguish between 1αp and 1βp see ref 34
    • C2,H3eq can be used to distinguish between 1αp and 1βp (see ref 34).
  • 35
    • 51749092441 scopus 로고    scopus 로고
    • C2,C3 = 44.0 Hz).
    • C2,C3 = 44.0 Hz).
  • 37
    • 51749122913 scopus 로고    scopus 로고
    • CCC values in unsaturated systems mimics that observed in saturated systems (Klepach, T.; Carmichael, I.; Serianni, A. S., unpublished results).
    • CCC values in unsaturated systems mimics that observed in saturated systems (Klepach, T.; Carmichael, I.; Serianni, A. S., unpublished results).
  • 39
    • 51749115311 scopus 로고    scopus 로고
    • a, and n were optimized simultaneously during the data fit using the Solver Routine in Microsoft Excel.
    • a, and n were optimized simultaneously during the data fit using the Solver Routine in Microsoft Excel.
  • 45
    • 0000089343 scopus 로고    scopus 로고
    • Larger disparities between calculated and experimental J-couplings are not considered to arise from inherent limitations of the DFT methodology but rather from simplifications and assumptions in the structural models used to calculate the couplings. In saccharides, the latter often involve the conformational properties of exocyclic OH groups, which can exert a major effect on both JCH and JCC values. Density functional theory with the B3LYP functional is known to produce accurate structural and energetic parameters in most organic molecules. This particular functional is specifically parametrized to reproduce accurate thermochemistry and matches closely results from high-level composite methods such as the Gaussian03 approach. Work in this laboratory and by other investigators has shown high agreement between B3LYP predictions of indirect nuclear spin-spin coupling constants and calculated couplings obtained by accurate high-level coupl
    • CC (Cloran, F.; Carmichael, I.; Serianni, A. S. J. Phys. Chem. A 1999, 103, 3783-3795).


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.