A novel tricyclic dilactone isolated from an actinomycete derived from gineseng-cultivated soil

An actinomycete strain BYK1336, identified as Streptomyces cinerochromogenes, was isolated from 4-year-old ginseng farm. While culturing the strain and analyzing its chemical profile by liquid chromatography coupled with electrospray ionization mass spectrometer (LC-ESI-MS), a previously-unreported secondary metabolite BYK1336.360 was detected along with the known compounds belonging to the classes of ansatrienin and naphthomycins. The structure of BYK1336.360 was elucidated by comprehensive analysis of 1D and 2D NMR, mass spectrometric and infrared spectroscopic data. BYK1336.360 is structurally novel by bearing a cyclodecatriene flanked by six-membered and seven-membered lactone ring.