title: Two New Ergosterol Derivatives from the Basidiomycete Cortinarius glaucopus.
abstract: Two new sterols 1 and 2 and five known ones 3 - 7 were isolated for the first time from the fruiting bodies of Cortinarius glaucopus. Their structures were established by 1- and 2D-NMR spectra and HR-FABS-MS. The relative configuration of 1 was firmly determined by comparison of the observed1H-1H couplings and NOESY correlations, with those predicted for the computed geometries of the conformers. Calculations were performed by means of DFT with the B3LYP functional at 6-31 + G(d,p) level of theory, in CHCl3as the solvent. The structures of the new ergosterol derivatives, called glaucoposterol A (1) and B (2), were thus established as (3S,5R,7R,10R,13R,17R,20S,22R,23R,24R)-5,6-epoxy-3,7,23-trihydroxystrophast-8-en-14-one and (22E,3S,5S,9S,10R,13R,17R,20R,24R)-3,5-dihydroxyergosta-6,8(14),22-trien-15-one, respectively. Moreover, the configuration of known strophasterol C (3) was determined as (3S,5R,6S,7R,10R,13R,17R,20S,22S,24R). Glaucoposterol A (1) and strophasterol C (3) represent the second finding in nature of steroids with the rare strophastane skeleton.
authors.affiliation: Department of Chemistry, University of Mandalay, Bawdegone, 73rd Road Mahar Aung Myay Township, 100103, Mandalay, Myanmar.
authors.forename: Hnin Thanda
authors.initials: HT
authors.lastname: Aung
authors.affiliation: Dipartimento di Chimica and CEMEC, Università di Pavia, Via Taramelli 12, 27100, Pavia, Italy.
authors.forename: Alessio
authors.initials: A
authors.lastname: Porta
authors.affiliation: Dipartimento di Scienze Ambientali e della Vita, Università del Piemonte Orientale, Via Bellini 25/G, 15100, Alessandria, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Clericuzio
authors.affiliation: Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku, Nagoya, 468-8503, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Takaya
authors.affiliation: Dipartimento di Chimica and CEMEC, Università di Pavia, Via Taramelli 12, 27100, Pavia, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Vidari
mesh_terms: D001487:Basidiomycota; D005591:Chemical Fractionation; D055363:Cortinarius / Q000737:chemistry*; D004875:Ergosterol / Q000031:analogs & derivatives / Q000737:chemistry* / Q000302:isolation & purification*; D048690:Fruiting Bodies, Fungal / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010840:Phytosterols / Q000737:chemistry / Q000302:isolation & purification; D013237:Stereoisomerism
chemical_list: D010840:Phytosterols; D004875:Ergosterol
keywords: 
  Cortinarius glaucopus
  ; Basidiomycota; Ergosterol derivatives; Glaucoposterols; Strophastane derivatives