A brief overview on the methods for extraction and identification of flavonoids

Abstract

Flavonoids are active metabolites of plant cells. The significant biological role of these compounds is evidenced by the nature of their distribution in the plant. Flavonoids play an important role in plant reproduction, development and accumulation of pollen, and their content also determines the color of flowers, fruits, and plant seeds. Most flavonoids are found in actively functioning organs: leaves, flowers, fruits (color, aroma), seedlings, as well as in integumentary tissues that perform protective functions. Different organs and tissues differ in the quantity and qualitative composition of flavonoids. Relatively recently, it was found that flavonoids also influence signaling processes occurring in living systems due to specific interactions with proteins that perform regulatory functions. Numerous data have been accumulated on the influence of these compounds on other protein and non-protein structures, which can lead to changes in the functional state of cells and the entire organism as a whole. Despite the fact that currently the redox properties of phenolic compounds are not given so much importance, their comprehensive study still remains an important task. In addition, numerous studies confirm that flavonoids act as effective phytoalexins, exhibiting a wide range of antibacterial and antifungal activities. After all, a significant role of flavonoids is their function of protecting against various unfavorable factors for plants, such as temperature fluctuations, the influence of ultraviolet rays, attacks by viruses, bacteria, and parasites. A correlation has been established between their content in plants and plant resistance to fungal diseases and some pests. The appearance of these compounds in plants in response to the action of parasitic fungi of cultivated plants and inhibition of the growth of fungal mycelium is considered a protective reaction. Flavonoids with antimicrobial activity are found in large quantities in the seed coat. This review paper highlights the basic technologies for extraction and identification of flavonoids from different type of plants.