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

Fifty-one flavonoids from Gutierrezia microcephala

The Structure of Ambrosiol. A New Sesquiterpene Lactone from Ambrosia psilostachya

Flavonol methyl ethers from Chrysothamnus viscidiflorus

Die flavonolglykoside von Equisetum silvaticum

In addition to the three known daucane esters (2,3,8) and one phenylpropanoid (9), the petroleum ether extract of the roots of Ferula tingitana yielded four new daucane esters: 14-p-anisoyloxy-dauc-4,8-diene (1), acetyltingitanol (4), acetyldesoxodehydrolaserpitine (5), and 4-beta-hydroxy-6-alpha-p-hydroxybenzoyloxy-10-alpha-angeloyloxy dauc-8-ene (6). A possible biogenetic pathway for 1,5-cis- and 1,5-trans-daucanes is presented.

Tom J. Mabry

Papers

Fifty-one flavonoids from Gutierrezia microcephala

The Structure of Ambrosiol. A New Sesquiterpene Lactone from Ambrosia psilostachya

Flavonol methyl ethers from Chrysothamnus viscidiflorus

Die flavonolglykoside von Equisetum silvaticum

New daucane esters from Ferula tingitana.