
International Agency for Research on Cancer (IARC) - Summaries & Evaluations
PYRIDO[3,4-c]PSORALEN AND 7-METHYLPYRIDO[3,4-c]PSORALEN
VOL.: 40 (1986) (p. 349)
Pyrido[3,4-c]psoralen
CAS No.: 85878-62-2
Chem. Abstr. Name: 5H-Furo[3',2':6,7][1]benzopyrano[3,4-c]pyridin-5-one
7-Methylpyrido[3,4-c]psoralen
CAS No.: 85878-63-3
Chem. Abstr. Name: 7-Methyl-5H-furo[3',2':6,7][1]benzopyrano[3,4-c]pyridin-5-one
5. Summary of Data Reported and Evaluation
5.1 Exposure
There is no known human exposure to pyrido[3,4-c]psoralen or
7-methylpyrido[3,4-c]-psoralen, other than in limited clinical trials
for the treatment of psoriasis.
5.2 Experimental data
In one incompletely reported study of pyrido[3,4-c]psoralen and
7-methylpyrido[3,4-c]-psoralen in combination with ultraviolet A
radiation in mice, skin tumours were observed. No data were available
to evaluate the carcinogenicity to experimental animals of
pyrido[3,4-c]psoralen or 7-methylpyrido[3,4-c]psoralen in the absence
of ultraviolet A radiation.
No data were available to evaluate the reproductive effects or
prenatal toxicity of pyrido[3,4-c]psoralen or
7-methylpyrido[3,4-c]psoralen to experimental animals.
In the presence of ultraviolet A radiation, pyrido[3,4-c]psoralen and
7-methylpyrido[3,4-c]-psoralen bound covalently to isolated DNA. In
combination with ultraviolet A radiation,
7-methylpyrido[3,4-c]psoralen induced DNA damage in yeast and human
fibroblasts in vitro. Both compounds were mutagenic to Salmonella
typhimurium in the dark. In the presence of ultraviolet A radiation,
pyrido[3,4-c]psoralen and 7-methylpyrido[3,4-c]-psoralen induced
mutations and mitotic recombination in yeast. In the dark,
7-methylpyrido[3,4-c]psoralen, but not pyrido[3,4-d]psoralen, induced
sister chromatid exchanges in mammalian cells in vitro; and, in
combination with ultraviolet A irradiation, both compounds induced
sister chromatid exchanges in cultured mammalian cells.
5.3 Human data
No case report or epidemiological study of the carcinogenicity of
pyrido[3,4-c]psoralen or 7-methylpyrido[3,4-c]psoralen was available
to the Working Group.
5.4 Evaluation
There is inadequate evidence that pyrido[3,4-c]psoralen or
7-methylpyrido[3,4-c]-psoralen in combination with ultraviolet A
radiation is carcinogenic to experimental animals. No data were
available to evaluate the carcinogenicity of pyrido[3,4-c]psoralen or
7-methylpyrido[3,4-c]psoralen to experimental animals in the absence
of ultraviolet A radiation.
No evaluation could be made of the carcinogenicity of
pyrido[3,4-c]psoralen or 7-methylpyrido[3,4-c]psoralen to humans.
For definition of the italicized terms, see Preamble Evaluation.
Subsequent evaluation: Suppl. 7 (1987) (p. 71: Group 3)
Synonym for Pyrido[3,4-c]psoralen
- 4-(6-Hydroxy-5-benzofuranyl)nicotinic acid, d-lactone
Synonym for 7-Methylpyrido[3,4-c]psoralen
- 4-(6-Hydroxy-7-methyl-5-benzofuranyl)nicotinic acid, delta-lactone;
Last updated: 21 April 1998
See Also:
Toxicological Abbreviations