α-Pyrones from the marine-derived actinomycete Nocardiopsis dassonvillei subsp. dassonvillei XG-8-1

Seven new α-pyrones, nocapyrones H–N (1–7) were isolated from the marine-derived actinomycete strain, Nocardiopsis dassonvillei subsp. dassonvillei XG-8-1. The new structures 1–7 were determined by spectroscopic analysis, CD spectra, ECD quantum chemical calculations and the modified Mosher's method. Compounds 1, 2 and 6 showed inhibitory effects on quorum sensing (QS) controlled gene expression in Chromobacterium violaceum CV026 and Pseudomonas aeruginosa QSIS-lasI biosensors at a concentration of 100 μg mL−1, respectively. This is the first report of inhibition of α-pyrones on QS controlled gene expression in pathogenic bacteria.