Antioxidant aromatic butenolides from an insect-associated Aspergillus iizukae
Lin-Jiao Li, Tian-Xiao Li, Ling-Yi Kong, Ming-Hua Yang
Four new aromatic butenolides named aspernolides H-K (1–4), along with three known compounds (5–7), were isolated from the metabolites of Aspergillus iizukae, which resided in the guts of cricket species Gryllus testaceus. The structures were elucidated by extensive spectroscopic analysis, modified Mosher methods and Mo2(OAc)4-induced electronic circular dichroism (ECD) experiments. Their antioxidant activities were evaluated through ABTS and DPPH radical scavenging assays. Compounds 3, 5, and 7exhibited significant activities with IC50 values of 29.46, 9.59 and 12.36 μM, respectively, compared with the positive control trolox (IC50 13.11 μM).
Circular dichroism, Stereochemistry, Medicinal