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

Flavonoids of Baptisia australis (Leguminosae)

The flavonoid pigments of opuntia lindheimeri

From the leaves and the flowers of Helianthus glaucophyllus and Helianthus microcephalus, three new guaianolides were isolated. H. microcephalus afforded another two new guaianolides, the highly unsaturated guaianolide, the flavane, the flavone, and three flavonols. Structures of all the compounds were determined by spectral analysis.

Sesquiterpene lactones and flavonoids from Helianthus species.

Wax esters from Larrea divaricata

Subtype PIII sieve-element plastids, anthocyanins, spinulose, perforate-tectate pollen grains and the specific seed-coat sculpturing found in twoMacarthuria species (M. australis, M. neocambrica) consolidate their placement withinMolluginaceae. The unique form of the sieve-element plastids, i.e. with cubic crystals and starch grains (PIIIc″fs), finds its closest counter-part inLimeum. The multiple intertwinement of different genera of theMolluginaceae with many other centrospermous families led to a consideration of their more central position withinCaryophyllales.

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Tom J. Mabry

Papers

Flavonoids of Baptisia australis (Leguminosae)

The flavonoid pigments of opuntia lindheimeri

Sesquiterpene lactones and flavonoids from Helianthus species.

Wax esters from Larrea divaricata

Ultrastructural, Micromorphological and Phytochemical Evidence for a “Central Position” of Macarthuria (Molluginaceae) within the Caryophyllales