Abstract

Two viridin-related B-norsteroids, B-norviridiol lactone (1) and B-norviridin enol (2), both possessing distinct unprecedented carbon skeletons, were isolated from a liquid culture of the ash dieback-causing fungus Hymenoscyphus pseudoalbidus. Compound 2 was found to degrade to a third B-norsteroidal compound, 1β-hydroxy-2α-hydro-asterogynin A (3), which was later detected in the original culture. The proposed structure of 1 is, regarding connectivity, identical to the original erroneous structure for TAEMC161, which was later reassigned as viridiol. Compound 2 showed an unprecedented 1H-13C HMBC correlation through an intramolecular hydrogen bond. The five-membered B-ring of compounds 1–3 was proposed to be formed by a benzilic acid rearrangement. The known compound asterogynin A was found to be formed from 3 by a β-elimination of water. All compounds were characterized by NMR spectroscopy, LC-HRMS and polarimetry.

Published in

Molecules
2012, Volume: 17, number: 7, pages: 7769-7781

SLU Authors

• Andersson, Pierre

  • Department of Molecular Sciences, Swedish University of Agricultural Sciences
    

• Bengtsson, Stina

  • Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences
    

• Stenlid, Jan

  • Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences
    

• Broberg, Anders

  • Department of Molecular Sciences, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Organic Chemistry
Microbiology


Publication identifier

DOI: https://doi.org/10.3390/molecules17077769

Permanent link to this page (URI)

https://res.slu.se/id/publ/39248