Five unprecedented chromone derivatives involving a 6/6/5/5/5/6 hexacyclic scaffold (1, 2), 6/6/5/6/6/6/6 heptacyclic scaffold (3), and 6/6/6/5/5/6 hexacyclic scaffold (4, 5) were obtained from the fungus Aspergillus deflectus NCC0415. Their structures were identified using comprehensive spectroscopic analysis, single-crystal X-ray diffraction, and electronic circular dichroism calculations. Except for 3, the other compounds, especially the 6/6/6/5/5/6 hexacyclic derivatives (4 and 5), exhibited potent inosine-5'-monophosphate dehydrogenase (IMPDH) inhibitory activities.