Two New Ergosterol Derivatives from the Basidiomycete Cortinarius glaucopus |
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Authors: | Hnin Thanda Aung Alessio Porta Marco Clericuzio Yoshiaki Takaya Giovanni Vidari |
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Institution: | 1. Department of Chemistry, University of Mandalay, Mandalay, Myanmar;2. Dipartimento di Chimica and CEMEC, Università di Pavia, Pavia, Italy;3. Dipartimento di Scienze Ambientali e della Vita, Università del Piemonte Orientale, Alessandria, Italy;4. Faculty of Pharmacy, Meijo University, Tempaku, Nagoya, Japan |
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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 observed 1H–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 CHCl3 as 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. |
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Keywords: |
Cortinarius glaucopus
Basidiomycota Ergosterol derivatives Strophastane derivatives Glaucoposterols |
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