Lyngbyatoxin-a is a type of alkaloid cyanotoxin produced by certain cyanobacteria species, most notably Moorea producens (formerly classified as Lyngbya majuscula).

It is produced as defense mechanism to ward off any would-be predators of the bacterium, being a potent blister agent as well as carcinogen.

[1][2][3][4][5][6] Lyngbyatoxin is a terpenoid indole alkaloid hybrid that belongs to the class of non-ribosomal peptides (NRPs).

[7] Lyngbyatoxin contains a nucleophilic indole ring that takes part in the activation of protein kinases.

The non-ribosomal peptide synthase (NRPS) LtxA protein condenses L-methyl-valine and L-tryptophan to form the linear dipeptide N-methyl-L-valyl-L-tryptophan.