17- [ 16,17-Dihydroxycyclooctatinyl]-hexaketide ester from Streptomyces sp. SR107

A new hexaketide acid esterified by the 17-hydroxyl group of 16,17-dihydroxycyclooctatin, namely 17-[16,17-dihydroxycyclooctatinyl]-hexaketide ester（1）, a member of the group of rare bacterial diterpenes with a fused 5-8-5 ring system was isolated from strain Streptomyces sp. SR107. The structure was determined on the basis of its spectral data（~1H NMR, ~（13） C NMR, ~1H-~1H COSY, HSQC, HMBC, NOESY, IR and HR-ESI-MS）. The antibacterial activity was also evaluated in this paper.