Aspergixanthones L-T, nine undescribed prenylxanthone derivatives from Aspergillus stellatus.

Nine undescribed prenylxanthone derivatives, aspergixanthones L-T (1-9), were isolated from the fungus Aspergillus stellatus. Compound 4 represents the first propionylated prenylxanthone, while compounds 7-9 are the first examples of prenylxanthones adorned with a 2,3-butanediol group. Their structures with absolute configurations were elucidated based on comprehensive spectroscopic analyses, ECD calculation, single-crystal X-ray diffraction, Mo2(OAc)4 induced ECD experiment, and Mosher's method. Compound 9 showed cytotoxic effects against several human cancer cell lines with the IC50 values ranging from 3.35 ± 0.58 to 8.62 ± 1.18 μM. Compounds 7 and 8 showed suppressive effects on NO production with IC50 values of 7.30 ± 0.69 and 5.16 ± 0.17 μM, respectively.