Studies on the Spectra of Protoberberine Alkaloids. II. Absorption Spectrum of Jatrorrhizine
| Autor: | Z. Gašparec, K. Weber |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 1967 |
| Zdroj: | Croatica Chemica Acta Volume 39 Issue 3 |
| ISSN: | 1334-417X 0011-1643 |
| Popis: | Measurements have been made on the visible and UV absorption spectra of jatrorrhizine chloride in pure aqueous, methanol, ethanol a nd propa nol solutions and in the p resence of various concentrations of e ither hydrochloric acid or potass ium h ydroxid e. In all the solutions, potassium hydroxide conside rably modifies the absorption curves. The modifications b ecome manifest in the disappearance of the absorption maximum and in the appearance of new bathochromic shifted maxima. In these changes isobestic points were noticed in the absorption curves. At very high potassium hydroxide concentrations in ethanol and propanol solutions, the absorption maximum disappears from the vis ible region of the spectrum. It has been suggested that the addition of potassium hydroxide causes the formation of the quinonoidic form of jatrorrhizine. The carbinolic form probably appears only in ethanol and propanol solutions. |
| Databáze: | OpenAIRE |
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