A Reactive Eremophilane and Its Antibacterial 2(1H)-Naphthalenone Rearrangement Product, Witnesses of a Microbial Chemical Warfare

作者：Amand Severine; Vallet Marine; Guedon Laura; Genta Jouve Gregory; Wien Frank; Mann Stephane; Dupont Joelle; Prado Soizic^*; Nay Bastien^*

来源：Organic Letters, 2017, 19(15): 4038-4041.

DOI：10.1021/acs.orglett.7b01788

Two sesquiterpenes, 4-epi-microsphaeropsisin (1) and a dihydrofurano-2(1H)-naphthalenone (variabilone, 2) which represents a new skeleton, were isolated from endophytic fungus Paraconiothyrium variabile. Reactivity studies showed that eremophilane 1 is a precursor of 2 through acid-promoted methyl 1,2-migration and aromatization. An electrophilic intermediate of this transformation was intercepted by N-acetylcysteamine, a biomimetic nucleophile. Only compound 2 was antibacterial against endophytic bacterium Bacillus subtilis (coisolated with P. variabile), suggesting a role in the microbial competition in plants.

• 出版日期2017-8-4