Structure-antioxidant activity relationships of flavonoids and phenolic acids

http://amborella.net/2010PlantSystematics/DATA/3-24-APG%202003%20Bot%20J%20Linn%20Soc%20APGII.pdf

An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG II

Flavonoids are nearly ubiquitous in plants and are recognized as the pigments responsible for the colors of leaves, especially in autumn. They are rich in seeds, citrus fruits, olive oil, tea, and red wine. They are low molecular weight compounds composed of a three-ring structure with various substitutions. This basic structure is shared by tocopherols (vitamin E). Flavonoids can be subdivided according to the presence of an oxy group at position 4, a double bond between carbon atoms 2 and 3, or a hydroxyl group in position 3 of the C (middle) ring. These characteristics appear to also be required for best activity, especially antioxidant and antiproliferative, in the systems studied. The particular hydroxylation pattern of the B ring of the flavonoles increases their activities, especially in inhibition of mast cell secretion. Certain plants and spices containing flavonoids have been used for thousands of years in traditional Eastern medicine. In spite of the voluminous literature available, however, Western medicine has not yet used flavonoids therapeutically, even though their safety record is exceptional. Suggestions are made where such possibilities may be worth pursuing.

The Effects of Plant Flavonoids on Mammalian Cells:Implications for Inflammation, Heart Disease, and Cancer

Estimation of total flavonoid content in propolis by two complementary colorimetric methods

Antimicrobial activity of flavonoids

In 1949 betalains were reported to possibly co-occur with an anthocyanidin (cyanidin) in Carpobrotus edulis; however, upon re-examination of this plant, only betalains and leucoanthocyanidins were detected. Thus, to date, all evidence indicates that the two classes of plant pigments, betalains and anthocyanins, are mutually exclusive. The detection of betalains in seven species belonging to the family Amaranthaceae and ten species of the Chenopodiaceae are also reported.

On the question of the mutual exclusiveness of betalains and anthocyanins

Flavonoid chemistry of Chenopodium fremontii. Infraspecific variation and systematic implications at the interspecific level

New Flavonoids from Sugarcane (Saccharum)

http://science.sciencemag.org/content/sci/142/3592/545.full.pdf

Tom J. Mabry

Papers

On the question of the mutual exclusiveness of betalains and anthocyanins

Flavonoid chemistry of Chenopodium fremontii. Infraspecific variation and systematic implications at the interspecific level

New Flavonoids from Sugarcane (Saccharum)

Perspectives in chemotaxonomy.

Flavonoids of four species of Parthenium (compositae)