Tistrellabactins A and B Are Photoreactive C-Diazeniumdiolate Siderophores from the Marine-Derived Strain Tistrella mobilis KA081020-065

J Nat Prod. 2023 Jul 28;86(7):1770-1778. doi: 10.1021/acs.jnatprod.3c00230. Epub 2023 Jun 21.


The C-diazeniumdiolate group in the amino acid graminine is emerging as a new microbially produced Fe(III) coordinating ligand in siderophores, which is photoreactive. While the few siderophores reported from this class have only been isolated from soil-associated microbes, here we report the first C-diazeniumdiolate siderophores tistrellabactins A and B, isolated from the bioactive marine-derived strain Tistrella mobilis KA081020-065. The structural characterization of the tistrellabactins reveals unique biosynthetic features including an NRPS module iteratively loading glutamine residues and a promiscuous adenylation domain yielding either tistrellabactin A with an asparagine residue or tistrellabactin B with an aspartic acid residue at analogous positions. Beyond the function of scavenging Fe(III) for growth, these siderophores are photoreactive upon irradiation with UV light, releasing the equivalent of nitric oxide (NO) and an H atom from the C-diazeniumdiolate group. Fe(III)-tistrellabactin is also photoreactive, with both the C-diazeniumdiolate and the β-hydroxyaspartate residues undergoing photoreactions, resulting in a photoproduct without the ability to chelate Fe(III).

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Azo Compounds
  • Ferric Compounds*
  • Siderophores* / chemistry


  • Siderophores
  • diazeniumdiolate
  • Ferric Compounds
  • Azo Compounds

Supplementary concepts

  • Tistrella mobilis