Ansaetherone,a New Radical Scavenger from Streptomyces sp.

We identified a new radical scavenger, ansaetherone (C₂₆H₃₃NO₇), from a culture of the Streptomyces sp. USF-4727 strain. In our previous study, it was shown that this strain produced four lipoxygenase inhibitors, tetrapetalones A, B, C and D. The chemical structure of ansaetherone was elucidated by the spectroscopic method, indicating that this compound was constructed with an aglycon and a sugar moiety. This chemical structure suggested that ansaetherone was related to the tetrapetalones. This finding provided information regarding tetrapetalone biosynthesis. Ansaetherone showed radical scavenging activity with an ED₅₀ value of 300 μM in our assay.