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

The Systematic Identification of Flavonoids

Carbon-13 NMR studies of flavonoids. III. Naturally occurring flavonoid glycosides and their acylated derivatives

The methanol spectra of flavones and flavonols exhibit two major absorption peaks in the region 240 – 400 nm1. These two peaks are commonly referred to as Band I (usually 300 – 380 nm, Table V-1 records the λmaxvalues for Band I for all flavones and flavonols examined in the present investigation), and Band II (usually 240 – 280 nm). Band I is considered to be associated with absorption due to the B-ring cinnamoyl system, and Band II with absorption involving the A-ring benzoyl system (see III) [1].

The Ultraviolet Spectra of Flavones and Flavonols

A number of reviews of ultraviolet and visible absorption spectroscopy have appeared in the past (Jurd, 1962; Mabry et al., 1970; Swain, 1965; Mabry, 1969; Harborne, 1963) the most comprehensive being those of Jurd (1962) and Mabry et al., (1970). The article by Jurd summarizes the work in this field up to about 1960 and gives detailed references to the original spectroscopic work carried out with flavonoids. The book by Mabry et al (1970) updates Jurd’s chapter and in addition provides a detailed catalogue of the ultraviolet (UV) spectra of 175 flavonoids together with comprehensive data on reagent induced shifts for each flavonoid. The present article includes some of the more significant aspects of the earlier reviews and in addition brings them up to date.

Tom J. Mabry

Papers

The Systematic Identification of Flavonoids

Carbon-13 NMR studies of flavonoids. III. Naturally occurring flavonoid glycosides and their acylated derivatives

The Systematic Identification of Flavonoids

The Ultraviolet Spectra of Flavones and Flavonols

Ultraviolet-Visible and Proton Magnetic Resonance Spectroscopy of Flavonoids