Natural flavones include Apigenin (4',5,7-trihydroxyflavone), Luteolin (3',4',5,7-tetrahydroxyflavone) and Tangeritin (4',5,6,7,8-pentamethoxyflavone), chrysin(5,7-OH), 6-hydroxyflavone, baicalein (5,6,7-trihydroxyflavone), scutellarein (5,6,7,4'-tetrahydroxyflavone), wogonin (5,7 -OH, 8 -OCH3). Synthetic flavones are Diosmin and Flavoxate.
Metabolism in humans
Intake and putative beneficial effects
Flavones are mainly found in cereals and herbs. In the West, the estimated daily intake of flavones is in the range 20–50 mg per day. In recent years, scientific and public interest in flavones has grown enormously due to their putative beneficial effects against atherosclerosis, osteoporosis, diabetes mellitus and certain cancers. Flavones intake in the form of dietary supplements and plant extracts has been steadily increasing.
Natural dietary flavones, found in parsley, celery, and citrus peels, reactivate DLC1 (Deleted in Liver Cancer 1) expression in breast cancer cell lines which have decreased DLC1 expression due to promoter hypermethylation, and may potentially be used as an anti-cancer agent for prevention and therapy of breast and other DLC1 downregulated cancers.
In organic chemistry several methods exist for the synthesis of flavones:
- the Allan–Robinson reaction
- the Auwers synthesis
- the Baker–Venkataraman rearrangement
- the Algar–Flynn–Oyamada reaction
Another method is the dehydrative cyclization of certain 1,3-diaryl diketones 
The Wessely–Moser rearrangement (1930) has been an important tool in structure elucidation of flavonoids. It involves the conversion of 5,7,8-trimethoxyflavone into 5,6,7-trihydroxyflavone on hydrolysis of the methoxy groups to phenol groups. It also has synthetic potential for example:
This rearrangement reaction takes place in several steps: A ring opening to the diketone, B bond rotation with formation of a favorable acetylacetone-like phenyl-ketone interaction and C hydrolysis of two methoxy groups and ring closure.
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