Ansavaricin J, a New Heterocyclic Ring-Fused Streptovaricin from Gene stvP5-Deleted Mutant ofStreptomyces spectabilisCCTCC M2017417

A new ring-fused streptovaricin analogue, named ansavaricin J, was unprecedently isolated from the culture of the genetically modified strains Delta stvP5 which derived fromStreptomyces spectabilisCCTCC M2017417. Its structure was elucidatedviacomprehensive spectroscopic analyses, including 1D- and 2D-NMR tests, and HR-ESI-MS data analysis. Notably, ansavaricin J and E represent the only two reported examples of heterocyclic ring-fused streptovaricins thus far, however, it only showed insignificant antibacterial activities againstStaphylococcus aureus.