Physical Properties and Identification of Flavonoids by Ultraviolet-Visible Spectroscopy

Abstract

Flavonoids are major functional components of many vegetable or animal preparations with medical uses. Flavonoids are also used in the treatment of numerous diseases, inhibiting specific enzymes, stimulating hormones and neurotransmitters and reducing the activity of free radicals. Due to the fact that flavonoids contain a variable number of phenolic groups in their chemical structure and due to their excellent properties to form chelates with iron and other transition metals, they have a high antioxidant capacity. For the human body, the antioxidant activity is highlighted due to the fact that they protect the cells of the body from free radicals that are formed as a result of numerous processes that use oxygen as an energy source and thus play an essential role in the protection of oxidative degradation phenomena. Their antiradical properties are due to hydroxyl and superoxide radicals, reactive groups that are involved in the initiation of lipid peroxidation processes, their ability to modify the synthesis of eicosanoids, to prevent platelet aggregation (antimicrobial effect) and to protect basic lipoproteins from oxidation. Although some studies indicate that some flavonoids possess a pro-oxidative action, this occurs only at high doses, and most investigations show the existence of anti-inflammatory, antiviral and anti-allergic effects, as well as the protective role in various pathologies.