Violapyrone J, alpha-Pyrone Derivative from a Marine-derived Actinomycetes, Streptomyces sp

A new alpha-pyrone derivative, violapyrone J (1), and along with the two known violapyrones B (2) and C (3) were isolated from the fermentation broth of a marine actinomycete Streptomyces sp. SC0718. The structure of violapyrone J (1) was elucidated from 1D and 2D NMR spectroscopic analyses.