Neisserin

Neisserin is a hypothetical natural product named in pedagogical discussions of bacterial metabolism, particularly within the context of the genus Neisseria. It is not an experimentally confirmed compound and no peer-reviewed report of its isolation or structure has been published. In such discussions, Neisserin is described as a small, nitrogen-rich heterocyclic molecule that functions as an iron chelator to support bacterial growth under iron-limited conditions. The hypothetical molecule is often presented as a siderophore-like metabolite with moderate to high aqueous solubility and a preference for ferric iron at neutral pH.

In speculative biosynthetic schemes, Neisserin is proposed to arise from a nonribosomal peptide synthetase (NRPS) or mixed NRPS-polyketide synthase pathway, with gene clusters labeled nerA–nerE in hypothetical Neisseria strains. The proposed biosynthesis would incorporate amino acid-derived building blocks and heterocyclic ring formation through cyclization and tailoring enzymes.

Occurrence and interpretation: As a teaching example, Neisserin is used to illustrate the concepts of iron acquisition, nutrient limitation, and host-pathogen interactions in the Neisseria lineage. It has no known spectroscopic signature or isolated sample in public records; therefore, it remains a conceptual construct rather than an established natural product.

See also: Siderophores, Neisseria, Nonribosomal peptide synthetases.