Page 14 - phytochemistry II -pharmD general

Purification of Alkaloidal Extracts

After distillation of the solvent used for extraction of alkaloids from powered
plants the conc. alk. ext. (or crude alk. extract) is further purified by either:

1. Precipitation ( two methods).
2. Partition process (acid-base purification)
3. Chromatography.

Precipitation

II. Precipitation of alkaloids with alkaloids precipitating reagents
Examples of the alkaloidal pptating agent e.g. Mayer’s, wagner’s, dragendorff’s
The insoluble alk-complex with these reagents are purified by :

1. Filtration.
2. Decomposition of the insoluble alk-complex to get the free alkaloid

(regeneration).
3. Extraction of the free alk. base with suitable organic solvent.

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