کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5406902 | 1393193 | 2009 | 5 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Structural analysis of uniformly 13C-labelled solids from selective angle measurements at rotational resonance
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
We demonstrate that individual H-C-C-H torsional angles in uniformly labelled organic solids can be estimated by selective excitation of 13C double-quantum coherences under magic-angle spinning at rotational resonance. By adapting a straightforward one-dimensional experiment described earlier [T. Karlsson, M. Eden, H. Luhman, M.H. Levitt, J. Magn. Reson. 145 (2000) 95-107], a double-quantum filtered spectrum selective for Cα and Cβ of uniformly labelled l-[13C,15N]valine is obtained with 25% efficiency. The evolution of Cα-Cβ double-quantum coherence under the influence of the dipolar fields of bonded protons is monitored to provide a value of the Hα-Cα-Cβ-Hβ torsional angle that is consistent with the crystal structure. In addition, double-quantum filtration selective for C6 and C1â² of uniformly labelled [13C,15N]uridine is achieved with 12% efficiency for a 13C-13C distance of 2.5 Ã
, yielding a reliable estimate of the C6-H and C1â²-H projection angle defining the relative orientations of the nucleoside pyrimidine and ribose rings. This procedure will be useful, in favourable cases, for structural analysis of fully labelled small molecules such as receptor ligands that are not readily synthesised with labels placed selectively at structurally diagnostic sites.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Magnetic Resonance - Volume 199, Issue 2, August 2009, Pages 242-246
Journal: Journal of Magnetic Resonance - Volume 199, Issue 2, August 2009, Pages 242-246
نویسندگان
Simon G. Patching, Rachel Edwards, David A. Middleton,