ContaminantDB: Methoxsalen

Identification Taxonomy Biological Properties Physical Properties Toxicity Profile Spectra Concentrations Links References Targets (5)XML

Record Information

Version

1.0

Creation Date

2009-06-08 20:21:21 UTC

Update Date

2026-03-26 22:54:20 UTC

Accession Number

CHEM000734

Identification

Common Name

Methoxsalen

Class

Small Molecule

Description

Methoxsalen is only found in individuals that have used or taken this drug. It is a naturally occurring furocoumarin compound found in several species of plants, including Psoralea corylifolia. It is a photoactive substance that forms DNA adducts in the presence of ultraviolet A irradiation. After activation Methoxsalen binds preferentially to the guanine and cytosine moieties of DNA, leading to cross-linking of DNA, thus inhibiting DNA synthesis and function.

Contaminant Sources

FooDB Chemicals
HMDB Contaminants - Urine
HPV EPA Chemicals
IARC Carcinogens Group 1
OECD HPV Chemicals
STOFF IDENT Compounds
T3DB toxins
ToxCast & Tox21 Chemicals

Contaminant Type

Aromatic Hydrocarbon
Cross-Linking Reagent
Drug
Ester
Ether
Food Toxin
Furocoumarin
Metabolite
Natural Compound
Organic Compound
Photosensitizing Agent
Pigmenting Agent
Plant Toxin

Chemical Structure

MOL SDF PDB SMILES InChI

Synonyms

Value	Source
6-Hydroxy-7-methoxy-5-benzofuranacrylic acid delta-lactone	ChEBI
8-Methoxy-2',3',6,7-furocoumarin	ChEBI
8-Methoxy-4',5':6,7-furocoumarin	ChEBI
8-Methoxy-[furano-3'.2':6.7-coumarin]	ChEBI
8-Methoxyfuranocoumarin	ChEBI
8-Methoxypsoralen	ChEBI
8-MOP	ChEBI
8-MP	ChEBI
9-Methoxy-7H-furo[3,2-g][1]benzopyran-7-one	ChEBI
Meladinine	ChEBI
Meloxine	ChEBI
O-Methylxanthotoxol	ChEBI
Oxsoralen	ChEBI
Ultra mop	ChEBI
Uvadex	ChEBI
Xanthotoxin	ChEBI
6-Hydroxy-7-methoxy-5-benzofuranacrylate delta-lactone	Generator
6-Hydroxy-7-methoxy-5-benzofuranacrylate δ-lactone	Generator
6-Hydroxy-7-methoxy-5-benzofuranacrylic acid δ-lactone	Generator
Methoxalen	HMDB
Xanthotoxine	HMDB
Xanthoxin	HMDB
Zanthotoxin	HMDB
8 MOP	HMDB
Chinoin brand OF methoxsalen	HMDB
Dermox	HMDB
Geroxalen	HMDB
ICN brand 2 OF methoxsalen	HMDB
Methoxsalen mex-america brand	HMDB
Oxsoralen ultra	HMDB
Oxsoralen-ultra	HMDB
8 Methoxypsoralen	HMDB
Ammoidin	HMDB
DB Brand OF methoxsalen	HMDB
Deltasoralen	HMDB
Meladinina	HMDB
Methoxsalen Delta brand	HMDB
Mex-america brand OF methoxsalen	HMDB
Méladinine	HMDB
Sanofi-synthelabo brand OF methoxsalen	HMDB
8MOP	HMDB
Boehringer ingelheim brand OF methoxsalen	HMDB
Galderma brand OF methoxsalen	HMDB
Methoxa-dome	HMDB
Methoxsalen canderm brand	HMDB
Methoxsalen chinoin brand	HMDB
Methoxsalen dermatech brand	HMDB
Methoxsalen sanofi-synthelabo brand	HMDB
Puvalen	HMDB
Sanofi synthelabo brand OF methoxsalen	HMDB
Ultramop	HMDB
Canderm brand OF methoxsalen	HMDB
Delta Brand OF methoxsalen	HMDB
Dermatech brand OF methoxsalen	HMDB
ICN brand 1 OF methoxsalen	HMDB
ICN brand 3 OF methoxsalen	HMDB
Methoxa dome	HMDB
Mex america brand OF methoxsalen	HMDB

Chemical Formula

C₁₂H₈O₄

Average Molecular Mass

216.192 g/mol

Monoisotopic Mass

216.042 g/mol

CAS Registry Number

298-81-7

IUPAC Name

9-methoxy-7H-furo[3,2-g]chromen-7-one

Traditional Name

methoxsalen

SMILES

COC1=C2OC(=O)C=CC2=CC2=C1OC=C2

InChI Identifier

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

InChI Key

QXKHYNVANLEOEG-UHFFFAOYSA-N

Chemical Taxonomy

Description

belongs to the class of organic compounds known as 8-methoxypsoralens. These are psoralens containing a methoxy group attached at the C8 position of the psoralen group.

Kingdom

Organic compounds

Super Class

Phenylpropanoids and polyketides

Class

Coumarins and derivatives

Sub Class

Furanocoumarins

Direct Parent

8-methoxypsoralens

Alternative Parents

Substituents

8-methoxypsoralen
Benzopyran
1-benzopyran
Benzofuran
Anisole
Alkyl aryl ether
Pyranone
Pyran
Benzenoid
Furan
Heteroaromatic compound
Lactone
Oxacycle
Ether
Organoheterocyclic compound
Organic oxygen compound
Organooxygen compound
Hydrocarbon derivative
Organic oxide
Aromatic heteropolycyclic compound

Molecular Framework

Aromatic heteropolycyclic compounds

External Descriptors

aromatic ether (CHEBI:18358 )
psoralens (CHEBI:18358 )
Polyketides (C01864 )
Furanocoumarins (C01864 )
an 8-methoxyfurocoumarin (CPD-13042 )

Biological Properties

Status

Detected and Not Quantified

Origin

Exogenous

Cellular Locations

Cytoplasm
Extracellular
Membrane

Biofluid Locations

Not Available

Tissue Locations

Not Available

Pathways

Not Available

Applications

Biological Roles

plant metabolite

Chemical Roles

Not Available

Physical Properties

State

Solid

Appearance

White powder.

Experimental Properties

Property	Value
Melting Point	148°C
Boiling Point	Not Available
Solubility	47.6 mg/L (at 30°C)

Predicted Properties

Property	Value	Source
Water Solubility	0.16 g/L	ALOGPS
logP	2.1	ALOGPS
logP	1.78	ChemAxon
logS	-3.1	ALOGPS
pKa (Strongest Basic)	-2.9	ChemAxon
Physiological Charge	0	ChemAxon
Hydrogen Acceptor Count	2	ChemAxon
Hydrogen Donor Count	0	ChemAxon
Polar Surface Area	48.67 Å²	ChemAxon
Rotatable Bond Count	1	ChemAxon
Refractivity	56.85 m³·mol⁻¹	ChemAxon
Polarizability	20.98 Å³	ChemAxon
Number of Rings	3	ChemAxon
Bioavailability	1	ChemAxon
Rule of Five	Yes	ChemAxon
Ghose Filter	Yes	ChemAxon
Veber's Rule	No	ChemAxon
MDDR-like Rule	No	ChemAxon

Spectra

Spectrum Type	Description	Splash Key	View
GC-MS	GC-MS Spectrum - GC-EI-TOF (Non-derivatized)	splash10-00ri-6940000000-921a3e8adbbde5f7a0c3	Spectrum
GC-MS	GC-MS Spectrum - GC-EI-TOF (Non-derivatized)	splash10-003b-4950000000-4e2c001531825f6dddca	Spectrum
GC-MS	GC-MS Spectrum - GC-EI-TOF (Non-derivatized)	splash10-00ri-6940000000-921a3e8adbbde5f7a0c3	Spectrum
GC-MS	GC-MS Spectrum - GC-EI-TOF (Non-derivatized)	splash10-003b-4950000000-4e2c001531825f6dddca	Spectrum
Predicted GC-MS	Predicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positive	splash10-000i-1920000000-98f6cfda190045d0762a	Spectrum
Predicted GC-MS	Predicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positive	Not Available	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - LC-ESI-qTof , Positive	splash10-014i-1590000000-f70cf2b0756e8c80c17b	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - LC-ESI-qTof , Positive	splash10-014i-0890000000-f76d6fb28854a5d7b6cd	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - LC-ESI-qTof , Positive	splash10-0fk9-0920000000-c2bd0b76c5aed757e904	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - LC-ESI-QTOF , positive	splash10-014i-0090000000-cecd035cc60695427f78	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - LC-ESI-QTOF , positive	splash10-0gb9-0290000000-2e17076c991ea61ced1a	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - LC-ESI-QTOF , positive	splash10-0uk9-0970000000-59c3b8004baa44f8d3a5	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - LC-ESI-QTOF , positive	splash10-014i-0190000000-cc04ec8c7265ba3a7297	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - LC-ESI-QTOF , positive	splash10-0udi-0970000000-82c4c7eefd54ad509f69	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - LC-ESI-QTOF , positive	splash10-00xs-0900000000-991b5b7dc028219e593b	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - Linear Ion Trap , positive	splash10-0udi-0970000000-dc6cd01d5d2e5eeaae30	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - Linear Ion Trap , positive	splash10-0udi-0970000000-ee8aa480dca6e72a74fb	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - , positive	splash10-014i-0890000000-f76d6fb28854a5d7b6cd	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - , positive	splash10-014i-1590000000-f70cf2b0756e8c80c17b	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - , positive	splash10-0fk9-0920000000-c2bd0b76c5aed757e904	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - , positive	splash10-0gi0-1960000000-82bc07f73bc5b2044642	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - , positive	splash10-014i-0690000000-770dc5d0db7e86d8ba07	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - 50V, Positive	splash10-00dj-0900000000-b06196cd7070da3a2e98	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - 15V, Positive	splash10-014i-0090000000-ed4db851d39c50628cea	Spectrum
LC-MS/MS	LC-MS/MS Spectrum - 45V, Positive	splash10-0uxr-0490000000-6e7169196da6a70b89d6	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 10V, Positive	splash10-014i-0090000000-4767833559e7bd183ce0	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 20V, Positive	splash10-014i-0090000000-c471bf567e8a63e00e51	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 40V, Positive	splash10-01bi-0930000000-72a72a3eb013e045bdb0	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 10V, Negative	splash10-014i-0290000000-c9557f276875a3bf1d2b	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 20V, Negative	splash10-014i-0390000000-ff927b8db6ef70ef822d	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 40V, Negative	splash10-00di-0910000000-d2e511be224be1b3530e	Spectrum
MS	Mass Spectrum (Electron Ionization)	splash10-014i-9670000000-3e0fa2e9c81c3bc1d936	Spectrum
1D NMR	1H NMR Spectrum	Not Available	Spectrum

Toxicity Profile

Route of Exposure

Not Available

Mechanism of Toxicity

Methoxsalen is a cholinesterase or acetylcholinesterase (AChE) inhibitor. A cholinesterase inhibitor (or 'anticholinesterase') suppresses the action of acetylcholinesterase. Because of its essential function, chemicals that interfere with the action of acetylcholinesterase are potent neurotoxins, causing excessive salivation and eye-watering in low doses, followed by muscle spasms and ultimately death. Nerve gases and many substances used in insecticides have been shown to act by binding a serine in the active site of acetylcholine esterase, inhibiting the enzyme completely. Acetylcholine esterase breaks down the neurotransmitter acetylcholine, which is released at nerve and muscle junctions, in order to allow the muscle or organ to relax. The result of acetylcholine esterase inhibition is that acetylcholine builds up and continues to act so that any nerve impulses are continually transmitted and muscle contractions do not stop. Among the most common acetylcholinesterase inhibitors are phosphorus-based compounds, which are designed to bind to the active site of the enzyme. The structural requirements are a phosphorus atom bearing two lipophilic groups, a leaving group (such as a halide or thiocyanate), and a terminal oxygen. The mechanism of action many furocoumarins is based on their ability to form photoadducts with DNA and other cellular components such as RNA, proteins, and several proteins found in the membrane such as phospholipases A2 and C, Ca-dependent and cAMPdependent protein-kinase and epidermal growth factor. Furocoumarins intercalate between base pairs of DNA and after ultraviolet-A irradiation, giving cycloadducts. (5).

Metabolism

Route of Elimination: In both mice and man, methoxsalen is rapidly metabolized. Approximately 95% of the drug is excreted as a series of metabolites in the urine within 24 hours (Pathak et al. 1977). Half Life: Approximately 2 hours

Toxicity Values

Not Available

Lethal Dose

Not Available

Carcinogenicity (IARC Classification)

Methoxsalen plus UVA radiation is carcinogenic to humans (Group 1). (4)

Uses/Sources

It is used to increase skin pigmentation with sunlight in the treatment of depigmentation conditions such as vitiligo and may cause skin burns and liver damage. (5). It is als used for the treatment of psoriasis and vitiligo.

Minimum Risk Level

Not Available

Health Effects

Acute exposure to cholinesterase inhibitors can cause a cholinergic crisis characterized by severe nausea/vomiting, salivation, sweating, bradycardia, hypotension, collapse, and convulsions. Increasing muscle weakness is a possibility and may result in death if respiratory muscles are involved. Accumulation of ACh at motor nerves causes overstimulation of nicotinic expression at the neuromuscular junction. When this occurs symptoms such as muscle weakness, fatigue, muscle cramps, fasciculation, and paralysis can be seen. When there is an accumulation of ACh at autonomic ganglia this causes overstimulation of nicotinic expression in the sympathetic system. Symptoms associated with this are hypertension, and hypoglycemia. Overstimulation of nicotinic acetylcholine receptors in the central nervous system, due to accumulation of ACh, results in anxiety, headache, convulsions, ataxia, depression of respiration and circulation, tremor, general weakness, and potentially coma. When there is expression of muscarinic overstimulation due to excess acetylcholine at muscarinic acetylcholine receptors symptoms of visual disturbances, tightness in chest, wheezing due to bronchoconstriction, increased bronchial secretions, increased salivation, lacrimation, sweating, peristalsis, and urination can occur. Certain reproductive effects in fertility, growth, and development for males and females have been linked specifically to organophosphate pesticide exposure. Most of the research on reproductive effects has been conducted on farmers working with pesticides and insecticdes in rural areas. In females menstrual cycle disturbances, longer pregnancies, spontaneous abortions, stillbirths, and some developmental effects in offspring have been linked to organophosphate pesticide exposure. Prenatal exposure has been linked to impaired fetal growth and development. Neurotoxic effects have also been linked to poisoning with OP pesticides causing four neurotoxic effects in humans: cholinergic syndrome, intermediate syndrome, organophosphate-induced delayed polyneuropathy (OPIDP), and chronic organophosphate-induced neuropsychiatric disorder (COPIND). These syndromes result after acute and chronic exposure to OP pesticides. Furocoumarins can cause photosensitization dermatitis especially if these compounds come into contact with the skin. Some furocoumarins, especially bifunctional furocoumarins, are known to be carcinogenic (1). Furocoumarin photochemotherapy is known to induce a number of side-effects including erythema, edema, hyperpigmentation, and premature aging of skin. All photobiological effects of furocoumarins result from their photochemical reactions. Because many dietary or water soluble furocoumarins are strong inhibitors of cytochrome P450s, they will also cause adverse drug reactions when taken with other drugs. Limited evidence of carcinogenic effect. (5)

Symptoms

Harmful if swallowed. May cause sensitisation by skin contact. (5)

Treatment

If the compound has been ingested, rapid gastric lavage should be performed using 5% sodium bicarbonate. For skin contact, the skin should be washed with soap and water. If the compound has entered the eyes, they should be washed with large quantities of isotonic saline or water. In serious cases, atropine and/or pralidoxime should be administered. Anti-cholinergic drugs work to counteract the effects of excess acetylcholine and reactivate AChE. Atropine can be used as an antidote in conjunction with pralidoxime or other pyridinium oximes (such as trimedoxime or obidoxime), though the use of '-oximes' has been found to be of no benefit, or possibly harmful, in at least two meta-analyses. Atropine is a muscarinic antagonist, and thus blocks the action of acetylcholine peripherally.

Concentrations

Not Available

External Links

DrugBank ID

HMDB ID

FooDB ID

Phenol Explorer ID

KNApSAcK ID