Zhang Y, Li XM, Proksch P, Wang BG. Ergosterimide, a new natural Diels-Alder adduct of a steroid and maleimide in the fungus Aspergillus niger.
Steroids 2007;
72:723-7. [PMID:
17628622 DOI:
10.1016/j.steroids.2007.05.009]
[Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2007] [Revised: 05/15/2007] [Accepted: 05/30/2007] [Indexed: 11/24/2022]
Abstract
Ergosterimide (1), a natural Diels-Alder adduct of ergosteroid and maleimide, was characterized from the culture extract of Aspergillus niger EN-13, an endophytic fungus isolated from the marine brown alga Colpomenia sinuosa. In addition, four known steroids including (22E,24R)-ergosta-5,7,22-trien-3beta-ol (2), (22E,24R)-ergosta-4,6,8(14),22-tetraen-3-one (3), (22E,24R)-5alpha,8alpha-epidioxyergosta-6,22-dien-3beta-ol (4), and (22E,24R)-ergosta-7,22-dien-3beta,5alpha,6beta-triol (5) were also isolated and identified. The structures of these compounds were elucidated by extensive analysis of 1D and 2D NMR and IR spectra and MS data. The plausible biosynthetic pathway of 1 was also discussed. To the best of our knowledge, 1 is the first natural Diels-Alder adduct of steroid and maleimide reported so far.
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