Among plant extracts, flavonoids and anthraquinones are the more common types of compounds, and they are mainly found in the flowers, rhizomes and leaves of plants. This article will introduce you [plant extracts] flavonoids and anthraquinones extraction and separation technology.
Flavonoids may differ greatly in chemical composition and properties, so there is no fixed method for extraction and separation. The following are three extraction and separation techniques for flavonoids:
1.Alkaline extraction and acid precipitation
Flavonoids are generally soluble in alkaline, and deposit after acidification. This method is simple and easy to implement in industry production, and the acid and alkali should not be excessive so as not to damage the original structure during heating. It can also prevent the formation of body salts and dissolve the precipitated flavonoids when dispersing. This will directly affect the yield.
2.macroporous resin adsorption method
When the plant water extract passes through the ion exchange resin, the flavonoids are broken and adsorbed on the resin. dilute to remove other water-soluble impurities, compounds are eluted from the resin with different concentrations of methanol or ethanol, and the alcohol is recovered. Total flavonoids.
3.Lead salt precipitation method
Dry the acid extracted fluid by evaporating, dissolved in water or alcohol, filtered, and a saturated aqueous solution of lead acetate is added to the solution to precipitate impurities, and filtered out impurities. The filtrate go through the sulfide gas to remove lead. Reduce pressure to concentrate. Stand still to get total flavoinds. For example, the extraction of isoflavones from astragalus is used in this method.