Theoretical calculations by the combined empirical force-field (EFF)-extended Huckel molecular orbital (EHMO) approach confirm that octalene and benzo-lcl-octalene present a-bond fixation with a common single bond between the cyclooctatetraene and cyclooctatriene fragments, whereas the structure of
Conformational studies of antiradiation agents by NMR: Cysteamine and its derivatives
✍ Scribed by Vithal M. Kulkarni; Girjesh Govil
- Publisher
- John Wiley and Sons
- Year
- 1977
- Tongue
- English
- Weight
- 418 KB
- Volume
- 66
- Category
- Article
- ISSN
- 0022-3549
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✦ Synopsis
The conformations of cysteamine, thiazolidine, and thiazolidine-4-carboxylic acid were determined in aqueous solutions using NMR spectroscopy. At physiological pH, the population ratio of gauche- and trans-conformers was 3:1. The gauche-rotamer is probably responsible for the antiradiation activity and acts through metal chelation involving sulfur and nitrogen atoms. The puckering of the thiazolidine ring was calculated using NMR coupling constants. The observed results were compared with those obtained in the solid state using X-ray diffraction.
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