Methoxsalen

Methoxsalen

Clinical data
Trade names	Oxsoralen-Ultra, Uvadex, 8-mop, Oxsoralen
AHFS/Drugs.com	Consumer Drug Information
ATC code	D05AD02 (WHO) D05BA02 (WHO)
Pharmacokinetic data
Biological half-life	~2 hours
Identifiers
IUPAC name 9-methoxy-7H-furo[3,2-g]chromen-7-one
CAS Number	298-81-7 Y
PubChem CID	4114
DrugBank	DB00553 Y
ChemSpider	3971 Y
UNII	U4VJ29L7BQ
KEGG	D00139 Y
ChEBI	CHEBI:18358 Y
ChEMBL	CHEMBL416 Y
NIAID ChemDB	001590
ECHA InfoCard	100.005.516
Chemical and physical data
Formula	C12H8O4
Molar mass	216.19 g/mol
3D model (Jmol)	Interactive image
SMILES COc1c2c(ccc(=O)o2)cc3c1occ3
InChI InChI=1S/C12H8O4/c1-14-12-10-8(4-5-15-10)6-7-2-3-9(13)16-11(7)12/h2-6H,1H3 Y Key:QXKHYNVANLEOEG-UHFFFAOYSA-N Y

Methoxsalen — also called xanthotoxin, marketed under the trade names Oxsoralen, Deltasoralen, Meladinine — is a drug used to treat psoriasis, eczema, vitiligo, and some cutaneous lymphomas in conjunction with exposing the skin to UVA light from lamps or 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. Levels of individual patient PUVA exposure were originally determined using the Fitzpatrick scale. The scale was developed after patients demonstrated symptoms of phototoxicity after oral ingestion of Methoxsalen followed by PUVA therapy. Chemically, methoxsalen belongs to a class of organic natural molecules known as furanocoumarins. They consist of coumarin annulated with furan. It can also be injected and used topically.

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. When these products are applied to skin and exposed to UVA radiation, the skin may turn brownish due to the phototoxic effects of methoxsalen present in the bergamot oil. Most modern perfumes containing bergamot have the Methoxsalen removed.

The biosynthetic pathway is a combination of the shikimate pathway, which produces umbelliferone, and the mevalonate pathway.