Furanocoumarin

Furocoumarins (including furanocoumarins ) are frequently used in umbellifers ago as hogweed (Giant Hogweed, Hogweed ) and Angelica ( angelica ), also in lozenge plants such as citrus plants ( including bergamot, lemon, lime, grapefruit, bitter orange, and others) as well as in a number of other plants. Furocoumarins are among the phytochemicals and serve as phytoalexins.

The basic framework of the furocoumarins coumarin fused with a furan ring. Known furocoumarins are xanthotoxin, psoralen and bergapten.

Like most α, β -unsaturated carbonyl compounds are very reactive furocoumarins. Under the influence of sunlight ( UVA and UVB ) Furocumarine be photoactivated. A prominent example is the toxic sap of giant hogweed ( giant hogweed ). The furocoumarins contained therein harm the human body in two ways:

• Photosensitizing / Photo Toxic: Get furocoumarins on the skin and sunlight (UV radiation ) are then exposed, it is depending on the severity to burn-like symptoms (redness, swelling, blistering, lesions, Photopigmentierung, scarring ). See also Berloque dermatitis, photo- dermatitis.
• Carcinogenic: Furocumarine go under UV exposure covalent bonds with the pyrimidine bases of DNA, a so crosslink the DNA double strands irreversibly with each other ( cross-linking ) and act by carcinogenic.

In medicine furocoumarins as bergapten, xanthotoxin or trimethylpsoralen be used for the treatment of psoriasis in the phototherapy and photochemotherapy.