Four 6H‐Dibenzo[b,d]pyran‐6‐one Derivatives Produced by the Endophyte Cephalosporium acremonium IFB‐E007

Two novel 6H‐dibenzo[b,d]pyran‐6‐one derivatives, graphislactone G (1) and graphislactone H (2), besides graphislactone A (3) and alternariol monomethyl ether (4) were isolated from the CHCl3/MeOH 1 : 1 extract of the solid‐substrate culture of Cephalosporium acremonium IFB‐E007, an endophytic fungus in Trachelospermum jasminoides (Lindl.) Lem. The structures of compounds 1 and 2 were unambiguously established as 2‐chloro‐7‐hydroxy‐3,9‐dimethoxy‐1‐methyl‐6H‐dibenzo[b,d]pyran‐6‐one and 7‐hydroxy‐3,4,9‐trimethoxy‐1‐methyl‐6H‐dibenzo[b,d]pyran‐6‐one, respectively, by a combination of spectroscopic analyses. Compound 1 was unique in its bearing a Cl‐atom. Anticancer tests showed that compounds 1–4 had pronounced activities against SW1116 cell with IC50 values of 21, 12, 8.5, and 14 μg ml−1, respectively.