## Abstract The ^13^C NMR spectrum (at natural abundance) of monomeric chlorophyll α in acetone‐__d__~6~ has been recorded to re‐examine the assignments of the low field (aromatic‐olefinic) region of the spectrum. The assignments, made by the examination of the fully coupled spectrum and by the use
Complete assignment of the noncarbonylic carbon-13 resonances of Tendamistat
✍ Scribed by H. Kessler; P. Schmieder; W. Bermel
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1990
- Tongue
- English
- Weight
- 673 KB
- Volume
- 30
- Category
- Article
- ISSN
- 0006-3525
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✦ Synopsis
The complete assignment of all noncarbonylic carbon-13 resonances a t natural abundance of the a-amylase inhibitor Tendamistat is presented. Such an assignment can help solve ambiguities in the proton spectrum and forms the basis for further measurements to obtain more structural or dynamic information. Using a nonenriched sample, the low sensitivity due to the small gyromagnetic ratio of 13C to 'H and the low natural abundance of 13C requires sensitive methods to obtain interpretable spectra. Thus all the NMR techniques used incorporate proton detection. With three different techniques, the HMQC, the HMQC with TOCSY-transfer, and the HMBC, a complete assignment based on the published proton chemical shifts (A. D. Kline, K. Wuthrich J. Mol. Biol. 192 (1986)) was possible with spectra recorded in a reasonable time. Especially the HMBC, which yields correlations via 'H-I3C long-range couplings, proved to be extremely valuable in the assignment procedure.
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