Chemotherapy resistance is one of
the main causes of lung cancer
treatment failure, and a combination regimen may be an effective way
to overcome this. Here we report 5 new (1–3, 7, and 9) and 15 known polyketides,
isolated from an endozoic Aspergillus niger. The
structures of the new compounds were determined by the interpretation
of IR, HRESIMS, NMR, and ECD spectra. The ESI-MS/MS fragmentation
of the isolated naphtho-γ-pyrone isomers in positive mode is
discussed. The effects of isolated compounds in combination with cisplatin
(DDP) on a DDP-resistant A549 cell line (A459/DDP) are investigated.
The most active compound, 12, could reduce the ratio
of GSH/GSSG, promote the generation of intracellular ROS, and cooperate
with DDP to down-regulated levels of Nrf2, Akt, HO-1, and NQO1, suggesting
that inhibition of Nrf2 and Akt pathways might be involved in the
combined effect of 12 and DDP in A549/DDP cells.