1. Ionization constants of a number of alkaloids used in medicine
- Author
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I. E. Kopylova, I. V. Persiyanova, M. E. Perel'son, and T. S. Semenova
- Subjects
Inorganic chemistry ,Potentiometric titration ,chemistry.chemical_element ,Protonation ,Plant Science ,General Chemistry ,Nitrogen ,General Biochemistry, Genetics and Molecular Biology ,chemistry.chemical_compound ,Ultraviolet visible spectroscopy ,Chelerythrine ,chemistry ,Ionization ,Chelidonine ,Sanguinarine - Abstract
The pKa values of a number of alkaloids in water or in aqueous ethanol have been measured by the potentiometric titration method: nuphleine — 4.59, 6.98; brevicolline — 5.17, 8.02; chelidonine — 6.40; sanguinarine — 7.32; chelerythrine — 7.53; stepharine — 8.48; d-pseudoephedrine — 9.49. For nuphleine and brevicolline, each of which has two nitrogen atoms capable of protonation, assignments have been made of pKa values to the corresponding atoms on the basis of the results of UV spectroscopy.
- Published
- 1984
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