title: Pityriacitrin -- an ultraviolet-absorbing indole alkaloid from the yeast Malassezia furfur.
abstract: As the main nitrogen source in Malassezia furfur, tryptophan induces the formation of fluorochromes and pigments, which make the yeast less sensitive to UV light. To detect a chemical UV filter, M. furfur (CBS 1878) was incubated at 30 degrees C for 14 days on a pigment-inducing medium and agar extracts were purified by column chromatography, preparative TLC and HPLC. Structural analysis of the pure metabolites was performed by mass spectroscopy and NMR. A yellow compound eluting from the column with 64% acetonitrile was found to be a potential UV filter because of its broad UV absorption (lambda(max) 389, 315, 289, 212 nm). It was an indole derivative (C(20)H(13)N(3)O; pityriacitrin) which had recently been shown to be a potent UV filter in bacteria. Its UV protective properties were confirmed in a yeast model and also in humans. Pityriasis versicolor induced by Malassezia yeasts is characterized by depigmented skin areas showing reduced melanin synthesis but no increased UV sensitivity. This UV protection might be explained by the presence of pityriacitrin which is produced by M. furfur.
authors.affiliation: Department of Dermatology, Justus Liebig University Giessen, Gaffkystrasse 14, 35385 Giessen, Germany. Peter.Mayser@derma.med.uni-giessen.de
authors.forename: Peter
authors.initials: P
authors.lastname: Mayser
authors.forename: Ute
authors.initials: U
authors.lastname: Schäfer
authors.forename: Hans-Joachim
authors.initials: HJ
authors.lastname: Krämer
authors.forename: Bernhard
authors.initials: B
authors.lastname: Irlinger
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Steglich
mesh_terms: D006801:Humans; D026121:Indole Alkaloids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D008290:Malassezia / Q000737:chemistry* / Q000528:radiation effects; D015394:Molecular Structure; D011836:Radiation Tolerance; D012867:Skin / Q000187:drug effects / Q000528:radiation effects; D013471:Sunburn / Q000517:prevention & control; D013473:Sunscreening Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D014466:Ultraviolet Rays
chemical_list: D026121:Indole Alkaloids; D013473:Sunscreening Agents; C470985:pityriacitrin