Separation and purification of total flavonids of Astragalus membranaceus with ethanol/phosphate aqueous two-phase system / 中国中药杂志

ABSTRACT

<p><b>OBJECTIVE</b>To study separation and purification of flavonids with ethanol/phosphate aqueous two-phase system.</p><p><b>METHOD</b>The diversity of phase separation ability and the distribution of target products in various systems were taken as indicators to analyze aqueous two-phase extraction systems and phase diagrams formed by ethanol and some common salts, screen out EtOH/ K2HPO4 system as the optimla system for extracting total flavonids, and study the impact of proportion of components in EtOH/K2 HPO4 system on the partition coefficient and phase ratio of flavonids.</p><p><b>RESULT AND CONCLUSION</b>The EtOH/K2 HPO4 system with omegaEtOH 36.05% and omegaKHPO4 18.20% has been proved as the optimal conditions for separating and purifying total flavonoids of Astragalus (TFA). Under this optimal condition, the partition coefficient and the extraction yield of TFA reached 10.33 and 96.6%, respectively. After extraction, the contents of A. membranaceus saponins and A. membranaceus polysaccharides in top and bottom phases were determined at the same time, showing that A. membranaceus saponins in the removal rate reached 92.01%, and A. membranaceus polysaccharides were totally concentrated in bottom water phase, indicating a removal rate of 100%. Therefore, this is beneficial to separate and purify total flavonids from A. membranaceus crude extracts.</p>