Aflatoxins from the endophytic fungus Aspergillus sp. Y-2 isolated from the critically endangered conifer Abies beshanzuensis

Two new [asperxins A (1) and B (2)] and four known (3–6) aflatoxins were isolated and identified from the endophytic fungus Aspergillus sp. Y-2, which was derived from the needles of the critically endangered conifer Abies beshanzuensis. Their structures were elucidated by extensive spectroscopic methods. Among the isolates, compounds 1 and 5 showed considerable cytotoxicities against the A549 and Hela human cancer cell lines, with IC50 values in the range of 7.5–16.8 μM.