Recent advances in the extraction, purification and analytical techniques for flavonoids from plants: Taking hawthorn as an example

Flavonoids, as an important medicinal material of hawthorn, can prevent hypertension and hyperlipidaemia, protect cardiovascular and cerebrovascular vessels, etc. Although considerable research has been conducted on the extraction, purification and analysis methods for hawthorn flavonoids, a comprehensive summary of these techniques is lacking. This review comprehensively summarised the advancements in extraction, purification and analysis methods for hawthorn flavonoids over the past two decades. The advantages and disadvantages of different methods were compared, and existing problems and future developments were analysed. The results of the comparison showed that flavonoids are well extracted by ultrasound- and microwave-assisted extraction. The joint application of high-speed counter-current chromatography–preparative liquid chromatography is effective in purifying the compounds, while spectrophotometry and liquid chromatography–mass spectrometry are the most widely used quantitative and qualitative analysis methods for the detection of hawthorn flavonoids. The combination of various methods, greening of solvents, automation of equipment and continuity of operation have become new trends in the development of current technologies. In the future, it is necessary to further strengthen the research on the biological activity of extracts obtained through different technologies. This review is significant for guiding the deep-processing production of high-value–added hawthorn products.