title: Intermediates in the oxidative pathway from torulene to torularhodin in the red yeasts Cystofilobasidium infirmominiatum and C. capitatum (Heterobasidiomycetes, Fungi).
abstract: Two red Cystofilobasidium spp. isolated from spring sap-flows of Betula pendula were analysed for their carotenoid content. In Cystofilobasidium infirmominiatum, three unusual pigments were detected and identified by structure elucidation as oxidised torulene derivatives. These included 16'-hydroxytorulene and torularhodinaldehyde, two carotenoids known so far only from chemical synthesis or as postulated biosynthetic intermediates en route to torularhodin. Unprecedented formation of beta-apo-2'-carotenal was also observed. The production of these pigments in pure culture was dependent on enhanced oxidative stress caused by cultivation in well-aerated (indented) flasks with or without 2% ethanol (16'-hydroxytorulene), or with 100 microM duroquinone (torularhodinaldehyde and beta-apo-2'-carotenal). Among these three pigments, only 16'-hydroxytorulene was detected in C. capitatum. Torularhodin, a common end product of carotenoid oxidation in red yeasts, was not produced by either species under any incubation conditions. Biosynthetic aspects of incomplete oxidation of torulene by these Cystofilobasidium spp. are discussed.
authors.affiliation: Department of Biotechnology, University of Kaiserslautern, Erwin-Schroedinger-Strasse 56, D-67663 Kaiserslautern, Germany.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Herz
authors.forename: Roland W S
authors.initials: RW
authors.lastname: Weber
authors.forename: Heidrun
authors.initials: H
authors.lastname: Anke
authors.forename: Adele
authors.initials: A
authors.lastname: Mucci
authors.forename: Paolo
authors.initials: P
authors.lastname: Davoli
mesh_terms: D001487:Basidiomycota / Q000378:metabolism*; D002338:Carotenoids / Q000096:biosynthesis / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D018384:Oxidative Stress
chemical_list: D002338:Carotenoids; C078922:torulene; C078923:torularhodin