Structural elucidation and NMR assignments of four aromatic lactones from a mangrove endophytic fungus (No. GX4‐1B)

Abstract Two new aromatic lactones, 6‐hydroxy‐4‐hydroxymethyl‐8‐methoxy‐3‐ methylisocoumarin (1) and 1,10‐dihydroxy‐8‐methyl‐dibenz[b, e]oxepin‐6,11‐dione (2), together with two known compounds, 1,10‐dihydroxy‐dibenz[b, e]oxepin‐6,11‐dione (3) and 3‐hydroxymethyl‐6,8‐dimethoxycoumarin (4), were isolated from a mangrove endophytic fungus (No. GX4‐1B) collected from the South China Sea. Their structures were elucidated and the data of 1 H and 13 C NMR were assigned completely by HREIMS, 1D and 2D NMR experiments including HMQC, HMBC and NOESY. Copyright © 2010 John Wiley & Sons, Ltd.