Anewhexaketideacidesterifiedbythe17-hydroxylgroupof16,17-dihydroxycyclooctatin,namely17-[16,17-dihydroxycyclooctatinyl]-hexaketideester(1),amemberofthegroupofrarebacterialditerpeneswithafused5-8-5ringsystemwasisolatedfromstrainStreptomycessp.SR107.Thestructurewasdeterminedonthebasisofitsspectraldata(~1HNMR,~(13)CNMR,~1H-~1HCOSY,HSQC,HMBC,NOESY,IRandHR-ESI-MS).Theantibacterialactivitywasalsoevaluatedinthispaper.