Nocardamin glucuronide, a new member of the ferrioxamine siderophores isolated from the ascamycin-producing strain Streptomyces sp. 80H647

A new siderophore glucuronide, nocardamin glucuronide ( 1 ), was isolated together with nocardamin ( 2 ) by applying the one strain-many compounds (OSMAC) approach to the ascamycin-producing strain, Streptomyces sp. 80H647, and performing multivariate analysis using mass spectral data. Structure elucidation was accomplished by a combination of NMR and MS analyses. The absolute configuration of the glucuronic acid moiety was found to be β- D -GlcA by hydrolysis using β-glucuronidase, subsequent derivatization of the hydrolysate, and comparison with standards. The siderophore activity of 1 was evaluated through the chrome azurol S assay and was comparable to that of 2 and deferoxamine (IC 50 13.4, 9.5, and 6.3 μM, respectively). Nocardamin glucuronide ( 1 ) is the first example of a siderophore glucuronide.