Discovery of A New Sesquiterpene-Lactone from Streptomyces aureus SP-371

A new sesquiterpene-lactone, designated as neopentalenolactone D1 (1), was isolated from the fermentation cultures of Streptomyces aureus SP-371, which is known for producing agricultural-bactericide aureonuclemycin.The chemical structure of compound 1 was determined to be a neopentapyrrole natural product with a 5/5/6 tricyclic skeleton and one amide functional group, by using spectroscopic techniques such as nuclear magnetic resonance (1D/2D NMR) and high-resolution mass spectrometry (HR-ESI-MS).Its structural information indicates that it is probably the shunt product of neopentalenolactone biosynthetic pathway.In antibacterial activity evaluations, compound 1 demonstrated no inhibitory effects against the tested strains including Escherichia coli (DH5α), Staphylococcus aureus, and Bacillus subtilis under the experimental conditions.