Amoenucles A−F, undescribed nucleoside derivatives with TNF-α inhibitory activities from Aspergillus amoenus TJ507

Amoenucles A−F (1−6), six undescribed nucleoside derivatives, and two known analogues (7 and 8), were isolated from the culture of Aspergillus amoenus TJ507. Their structures were determined by spectroscopic analysis, single-crystal X-ray crystallography, and chemical reactions. Significantly, 3 and 4 represented the first examples of nucleosides with an attached pyrrole moiety. More importantly, the absolute configuration of the sugar moiety of 1−4 was determined by NMR, ECD calculations and a hydrolysis reaction, that should be a useful method to confirm the structures of nucleosides. In addition, 1, 2, and 5−8 showed potential TNF-α (tumor necrosis factor α) inhibitory activities, that might provide a new chemical templating for the discovery of agents against autoimmune diseases and inflammatory diseases.