Pyranocoumarins
Pyranocoumarins are a class of chemical compounds that have a core structure that consists of a pyran ring fused to a coumarin. As phytochemicals, pyranocoumarins are uncommon and found mainly the plant families Apiaceae and Rutaceae. For example, ''Citrus sinensis'' and ''Citrus limonia'' are sources of xanthyletin and seselin. In the biosyntheses of pyranocoumarins, the pyran ring is formed via the methylerythritol phosphate pathway and the coumarin is derived from the shikimate pathway. See also * Furanocoumarin References

Pyrans Coumarins Heterocyclic compounds with 3 rings {{organic-compound-stub ...
[...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]  

Pyran
In chemistry, pyran, or oxine, is a six-membered heterocyclic, non-aromatic ring, consisting of five carbon atoms and one oxygen atom and containing two double bonds. The molecular formula is C5H6O. There are two isomers of pyran that differ by the location of the double bonds. In 2''H''-pyran, the saturated carbon is at position 2, whereas, in 4''H''-pyran, the saturated carbon is at position 4. 4''H''-Pyran was first isolated and characterized in 1962 via pyrolysis of 2-acetoxy-3,4-dihydro-2''H''-pyran. It was found too unstable, particularly in the presence of air. 4''H''-pyran easily disproportionates to the corresponding dihydropyran and the pyrylium ion, which is easily hydrolyzed in aqueous medium. Although the pyrans themselves have little significance in chemistry, many of their derivatives are important biological molecules, such as the pyranoflavonoids. The term pyran is also often applied to the saturated ring analog, which is more properly referred to as tetrahydrop ...
[...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]