Two new isochromenes, 1-(8-methoxy-3-methyl-1H-isochromen-6-yl)propan-1-one (1) and 3-hydroxy-1-(8- methoxy-3-methyl-1H-isochromen-7-yl)propan-1-one (2), along with five known ones, (3–7) were isolated from the fermentation products of a cigar tobacco-derived endophytic fungus Aspergillus fumigatus. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1 and 2 were evaluated for their antibacterial activities against Pseudomonas syringae (the main pathogenic sources of tobacco angular spot disease). Compounds 1 and 2 showed activity with MIC₅₀ values of 6.8 and 8.4 μg/mL, respectively, whereas the MIC₅₀ value of the positive control (agricultural streptomycin) is 2.2 μg/mL. The efficiencies of 1 and 2 are lower than that of the positive control.

两种新的异色烯，1-(8-甲氧基-3-甲基-1H-异色烯-6-基)丙-1-酮(1)和3-羟基-1-(8-甲氧基-3-甲基-1H-异色烯) -7-基)丙-1-一 (2) 以及五种已知的 (3-7) 是从雪茄烟内生真菌烟曲霉的发酵产物中分离出来的。它们的结构通过光谱方法阐明，包括广泛的一维和二维核磁共振技术。评估了化合物 1 和 2 对丁香假单胞菌（烟草角斑病的主要致病源）的抗菌活性。化合物 1 和 2 显示出活性，MIC ₅₀ 值分别为 6.8 和 8.4 μg/mL，而阳性对照（农用链霉素）的 MIC ₅₀ 值为 2.2 μg/mL 。 1和2的效率低于阳性对照。