Home > Xanthotoxin (Molecule of the Month for December 2012)

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C12H8O4

Methoxsalen is a drug used to treat psoriasis, eczema, vitiligo, and some cutaneous lymphomas in conjunction with exposing the skin to sunlight. Methoxsalen modifies the way skin cells receive the UVA radiation, allegedly clearing up the disease. The dosage comes in 10 mg tablets, which are taken in the amount of 30 mg 75 minutes before a PUVA (psoralen + UVA) light treatment.

Methoxsalen is extracted from Ammi majus, a plant of the family Apiaceae. The substance is also present in other Apiaceae as well as Rutaceae, for example bergamot oil which is used in many perfumes and aromatherapy oils. Chemically, methoxsalen belongs to a class of organic natural molecules known as furanocoumarins. They consist of coumarin annulated with furan.

Author John Howard Griffin used the chemical to darken his skin in order to investigate racial segregation in the south. He wrote the non-fiction book Black Like Me about his experiences. Some cologne/perfume contains bergamot oil as one of the ingredients (for the scent). People wearing the concoction on places where the skin receives UV radiation was radiated by the sun noticed that their skin turned brownish at those spots (due to the phototoxic effects of methoxsalen present in the bergamot oi). Most modern formulations of perfumes containing bergamot are de-methoxsalenised.

Formal Chemical Name (IUPAC)
9-methoxy-7H-furo[3,2-g]chromen-7-one

References

http://en.wikipedia.org/wiki/8-Methoxypsoralen

Update by Karl Harrison
(Molecule of the Month for December 2012 )