FERRER Evelina Gloria
capítulos de libros
Modification of flavonoid structure by oxovanadium(IV) complexation. Biological effects?.
Handbook on Flavonoids: Dietary Sources, Properties and Health Benefits.
Nova science publishers
Año: 2012; p. 100 - 146
Flavonoids are polyphenolic benzo-gamma-pyrone compounds that belong to a class of plant pigments. To date more than 6000 different plant flavonoid molecules have been identified. The interest in the bioactivity of the flavonoids of higher plants is due, at least in part, to the potential health benefits of these polyphenolic major dietary constituents. It has been shown that flavonoids possess both antioxidative and cytoprotective properties that also make them functional in traditional medicinal uses. It is well known that reactive oxygen species (ROS) contribute to the oxidative stress on the organism and are involved in many pathological processes such as inflammation, atherosclerosis, cancer, aging, etc. The antioxidant activities of flavonoids are responsible of their antibacterial, antiviral, and antitumoral effects. Besides, a relationship between their antioxidant activity, as free radical scavengers, and their chemical structures has been established. In particular, multiple hydroxyl groups confer substantial antioxidant and chelating activities, the presence of methoxy groups produces an increase of lipophilicity and unfavorable steric effects and the double bond in the heterocycle containing the carbonyl function affords a more stable flavonoid radical through conjugation and electron delocalization. Due to their transition metal chelation properties, another modification of the structure and evaluation of their activities is the generation of a metal coordination complex. Metal chelation may have important roles in the improvement of both the antioxidant properties and the antitumoral behavior. On the other hand, inorganic vanadium salts have been shown to have beneficial properties at low concentrations in animals, but these treatments have toxic side-effects. Organic vanadium compounds are much safer and some of them do not exert toxic effects. They act, among others, as insulin mimic and antitumoral agents. Therefore, the structure of the flavonoids can also been modified by coordination with oxovanadium(IV) cation. These modifications and the improvement of the antioxidant and antitumoral properties of these compounds are presented herein.