Two Pairs of New Bisabolane‐Type Sesquiterpenoids from Aspergillus sydowii

Abstract Two pairs of new bisabolane‐type sesquiterpenoids, (+)‐aspersydowin A (7 S ) [(+)‐ 1 ], (−)‐aspersydowin A (7 R ) [(−)‐ 1 ], (+)‐aspersydowin B (7 S ,11 S ) [(+)‐ 2 ], (−)‐aspersydowin B (7 R ,11 R ) [(−)‐ 2 ], along with six known compounds ( 1 – 8 ) were isolated from the fungus Aspergillus sydowii . Compounds 1 and 2 are enantiomers resolved by the Chiralpak IC, using a hexane‐ propan‐2‐ol mobile phase. The structure of 1 and 2 with absolute configuration were assigned tentatively by 1D ( 1 H, 13 C, and DEPT) & 2D (HSQC, 1 H– 1 H COSY, HMBC, and NOESY) NMR data analyses and ECD calculations. Compounds 1 – 8 were screened for the biological activities in vitro . The results showed that compounds 3 , 4 and 8 exhibited immunosuppressive activities with IC 50 values of 10.9, 17.6 and 13.4 μ M, respectively.