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

Distribution of flavonoids in twenty-one species of Oenothera

Flavonol glycosides and phenolics from Withania somnifera

Betalamic acid, the probable key intermediate in the biogenesis of all betalains, has been detected for the first time as a natural product in numerous species of plants belonging to families of the Order Centrospermae, has been obtained directly from the cleavage of the red beet pigment betanin, and has been characterized by the formation of betanidin when mixed with synthetic cyclodopa, and indicaxanthin on reaction with L-proline.

Tom J. Mabry

Papers

Distribution of flavonoids in twenty-one species of Oenothera

Flavonol glycosides and phenolics from Withania somnifera

Betalamic acid, a new naturally occurring pigment

The structure of tamaulipin-A: A new germacranolide from Ambrosia confertiflora DC. (Compositae)

6-Methoxyflavonols from Brickellia veronicaefolia (compositae)