+ Site Statistics
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

Photochemistry of benzothiazole models of pheo melanin

Photochemistry of benzothiazole models of pheo melanin

Photochemistry & Photobiology 39(1): 5-10

The photochemistry of several 4-hydroxy- and 4-methoxybenzothiazoles was investigated by laser flash photolysis. In aqueous solutions of ph 3-12, the 4-hydroxybenzothiazole chromophore undergoes monophotonic photoionization to afford eaq- with quantum yields on the order of 0.06; no evidence for triplet species was obtained. The spectra and stability of the resultant free radicals were determined using pulse radiolysis. In contrast, triplet transients with life-times on the order of 8 .mu.s are readily observable upon irradiation of the 4-methoxybenzothiazole analog. Triplet sensitization experiments with the water-soluble carotenoid crocetin were employed to obtain the triplet extinction coefficients and subsequently the triplet quantum yields. The significance of these differences in photochemical behavior is discussed in relationship to the photochemistry and photobiology of the epidermal melanin pigment pheomelanin.

(PDF 0-2 workdays service: $29.90)

Accession: 006110317

Download citation: RISBibTeXText

Related references

Pheo melanin photochemistry. Photochemistry & Photobiology 39(SUPPL): 36S, 1984

Pheo melanin photochemistry photolysis of model compounds. Photochemistry & Photobiology 36(2): 251-254, 1982

Free radical scavenging properties of melanin interaction of eu- and pheo-melanin models with reducing and oxidising radicals. Free Radical Biology & Medicine 26(5-6): 518-525, March, 1999

Photo destruction of pheo melanin. Photochemistry and Photobiology 26(6): 651-654, 1977

Pheo melanin in albino negroes. Yale Journal of Biology & Medicine 53(5): 396, 1980

Photochemistry of 4 hydroxy benzothiazole a model for pheomelanin photo degradation. Journal of the American Chemical Society 102(21): 6587-6590, 1980

Synthesis and analysis of pheo melanin degradation products 2. Journal of Organic Chemistry 49(6): 997-1000, 1984

Photo degradation of pheo melanin an in vitro model. Photochemistry and Photobiology 31(4): 359-362, 1980

Structural analysis of pheo melanin from yellow mice. Yale Journal of Biology & Medicine 53(5): 396, 1980

Effects of ph and wavelength upon the photo destruction of pheo melanin. Klaus, S N (Ed ) Pigment Cell, Vol 4 Biologic Basis Of Pigmentation; Proceedings Of The 10th International Conference, Cambridge, Mass , Usa, Oct 8-12, 1977 Xvi+358p S Karger: Basel, Switzerland; New York, N Y , Usa Illus P323-328, 1979, 1980

(Pheo)melanin photosensitizes UVA-induced DNA damage in cultured human melanocytes. Journal of Investigative Dermatology 111(4): 678-682, 1998

Photochemistry of melanin precursors. Pigment Cell Research 6(4 PART 2): 282, 1993

Photophysics and photochemistry of melanin. Journal of Investigative Dermatology 102(2): 264, 1994

Photo induced oxygen consumption in melanin systems 2. action spectra and quantum yields for pheo melanins. Photochemistry and Photobiology 39(6): 805-810, 1984

Photochemistry of melanin precursors: dopa, 5-S-cysteinyldopa and 2,5-S,S'-dicysteinyldopa. Photochemistry and Photobiology 44(6): 697-702, 1986