Characterization of Eight New Secondary Metabolites from the Mutant Strain G‐444 of Tubercularia sp. TF5

Abstract Eight new metabolites, including five new sesquiterpenoids, 10,11‐epoxyguaian‐10‐ol ( 1 ), 10,11‐epoxyguaian‐13‐ol ( 2 ), a new backbone sesquiterpene rearranged from guaiane ( 3 ), two 1,5 : 1,10‐disecoguaianes, 4 and 5 , two new dihydroisocoumarins, 7‐chloromellein‐4‐ol ( 6 ) and 7‐chloromellein‐5‐ol ( 7 ), and one new tetralone, 7‐chloroscytalone ( 8 ), were isolated from the mutant strain G‐444 of Tubercularia sp. TF5, an endophytic fungus of Taxus mairei , along with ten known compounds, 3,4‐dihydro‐4,8‐dihydroxy‐2 H ‐naphthalen‐1‐one ( 9 ), (3 R ,4 S )‐4‐hydroxymellein ( 10 ), 5‐formylmellein ( 11 ), 5‐carboxymellein ( 12 ), sporogen‐AO1 ( 13 ), tuberculariols A ( 14 ) and B ( 15 ), hymatoxin E ( 16 ), 4‐oxo‐4 H ‐pyran‐3‐acetic acid ( 17 ), and penicillic acid ( 18 ) . Their structures were elucidated by spectroscopic analyses including HR‐ESI‐MS, 1D‐ and 2D‐NMR (HMQC, HMBC, 1 H, 1 H‐COSY and NOESY). The antimicrobial activities of 1 – 8 were evaluated, but none showed any substantial effect.