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

Flavonoid Aglycones from Ageratina tomentella

Six trihydroxy-pentamethoxyflavones were synthesized to confirm the structure of 2', 5, 7-trihydroxy-3, 4', 5', 6, 8-pentamethoxyflavone, isolated from Gutierreizia microcephala.

Flavonoids Syntheses. IV. : Syntheses of 2', 3, 4', 5, 5', 6, 7, 8-Octaoxygenated Flavones

Systematic implications of flavonols in Zaluzania

Two nonprotein amino acids, cycasindene and cycasthioamide, along with eight known nonprotein amino acids, were isolated from the seeds of Cycas revoluta Thumb. The structures of cycasindene and cycasthioamide were elucidated as 3-[3′-amino-indenyl-2′]-alanine (1) and N -[glycinyl-alaninyl-11-thio]-5-one-pipecolic acid ( 2 ) by chemical and spectral methods.

Tom J. Mabry

Papers

Flavonoid Aglycones from Ageratina tomentella

Flavonoids Syntheses. IV. : Syntheses of 2', 3, 4', 5, 5', 6, 7, 8-Octaoxygenated Flavones

Systematic implications of flavonols in Zaluzania

Nonprotein Amino Acids from Cycas revoluta.

Flavonoids from Passiflora trinervia and Passiflora sanguinolenta