Pseudapenes A-C, sesquiterpenoids from the marine-derived fungus Pseudallescheria apiosperma F52-1

Three sesquiterpenoids pseudapenes A-C (1-3) were isolated from the marine-derived fungus Pseudallescheria apiosperma F52-1. Pseudapene A (1) has an unprecedented 2-methyl-5-methylene-3-(2-methylbut-2-ene)-dicyclo(3, 3, 0)-octane carbon skeleton and pseudapenes B (2) and C (3) possess an unique 2-methyl-4-methylene-2-(2-methylpent-2-ene)-dicyclo(3, 2, 0)-heptane chemical scaffold. Their structures were determined by use of MS and NMR spectroscopic data, and ECD, optical rotation and C-13 NMR calculations. (C) 2019 Elsevier Ltd. All rights reserved.