Diphenylcyclopropenone: Examination of potential contaminants, mechanisms of sensitization, and photochemical stability

Michael Wilkerson, J. Henkin, J. K. Wilkin

Research output: Contribution to journalArticle

43 Citations (Scopus)

Abstract

Diphenylcyclopropenone (DPCP) has recently been reported to be a potent contact sensitizer for the treatment of alopecia areata. DPCP is nonmutagenic in the Ames assay. Studies on chemical purity, stability, and mechanisms of action are lacking. DPCP is synthesized by cyclization of α,α'-dibromodibenzylketone. The latter elicits a reaction in guinea pigs sensitized to DPCP. We examined the commercial sample of DPCP by gas chromatography - mass spectrometry for the presence of contaminants. The stability of dilute solutions of DPCP in ethanol and cyclohexane to fluorescent light, sunlight, and heat was followed by ultraviolet (UV) spectrometry. The isosbestic point and half-life for this reaction were determined. We found no original or intermediate reagents in our sample. DPCP was found to decompose, forming diphenylacetylene on exposure to both sunlight and fluorescent light in less than 2 weeks. Samples shielded from the light at -70°C and at room temperature were stable over a 4-week period. The extent of decomposition was the same in both ethanol and cyclohexane. It is possible that DPCP may act as a prosensitizer with the actual sensitizer liberated by a photoactivated intermediate (stable, metastable, or unstable) or a combination of these.

Original languageEnglish (US)
Pages (from-to)802-807
Number of pages6
JournalJournal of the American Academy of Dermatology
Volume11
Issue number5 I
StatePublished - 1984
Externally publishedYes

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Sunlight
Light
Ethanol
Alopecia Areata
diphenylcyclopropenone
Cyclization
Gas Chromatography-Mass Spectrometry
Half-Life
Spectrum Analysis
Guinea Pigs
Hot Temperature
Temperature
Cyclohexane
biphenylacetylene

ASJC Scopus subject areas

  • Dermatology

Cite this

Diphenylcyclopropenone : Examination of potential contaminants, mechanisms of sensitization, and photochemical stability. / Wilkerson, Michael; Henkin, J.; Wilkin, J. K.

In: Journal of the American Academy of Dermatology, Vol. 11, No. 5 I, 1984, p. 802-807.

Research output: Contribution to journalArticle

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