A new look into the reaction between ergosterol and singlet oxygen in vitro

The reaction of ergosterol (ERGO) with singlet oxygen in vitro was studied by using different combinations of the photosensitizers (i.e. rose Bengal and eosine) and solvents (i.e. pyridine, ethanol and methyl tert-butyl ether) and all the products obtained were isolated and fully characterized (mp,...

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Detalles Bibliográficos
Autores principales: Ponce, M.A., Ramirez, J.A., Galagovsky, L.R., Gros, E.G., Erra-Balsells, R.
Formato: JOUR
Materias:
alcohol
carbon 13
eosin
ergosterol
photosensitizing agent
proton
pyridine
rose bengal
singlet oxygen
solvent
tert butyl methyl ether
article
carbon nuclear magnetic resonance
chemical analysis
chemical reaction
chemical structure
controlled study
in vitro study
isolation procedure
mass spectrometry
priority journal
proton nuclear magnetic resonance
stereochemistry
chemistry
light
radiation exposure
Eosine Yellowish-(YS)
Ergosterol
Light
Models, Molecular
Molecular Structure
Photosensitizing Agents
Rose Bengal
Singlet Oxygen
Solvents
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_1474905X_v1_n10_p749_Ponce
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
Descripción
Sumario:The reaction of ergosterol (ERGO) with singlet oxygen in vitro was studied by using different combinations of the photosensitizers (i.e. rose Bengal and eosine) and solvents (i.e. pyridine, ethanol and methyl tert-butyl ether) and all the products obtained were isolated and fully characterized (mp, Rf, UV, 1H-NMR, 13C-NMR, EI-MS, ESI-MS and HR-MS). In pyridine, together with the expected (22E -5α,8α-epidioxyergosta-6,22-dien-3β-ol, EEP, the keto derivative (22E)-3β-hydroxyergosta-5,8(9),22-trien-7-one, KE, was obtained. In ethanol the expected EEP was obtained together with (22E -5α,8α-epidioxyergosta-6,9,22-trien-3β-ol, EEP9(11), and (22E)-ergosta-6,9,22-triene-3β,5α,8α-triol, DHOE, as main products and (22E)-ergosta-5,7,9,22-tetraen-3β-ol, DHE, in trace amounts. In methyl tert-butyl ether, a complex mixture of EEP, KE, DHOE, EEP9(11), DHE, together with (22E -7α-hydroperoxy-ergosta-5,8(9),22-trien-3β-ol, EHP, and (22E -ergosta-5,8(9),22-triene-3β,7α-diol, EH, was obtained. The minor products were characterized and showed strong dependence on the reaction medium. The regioselective and stereoselective character of the singlet oxygen attack on the ERGO diene moiety is discussed in terms of ERGO HOMO's properties.

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