Pyoluteorin is a natural antibiotic that is biosynthesized from a hybrid nonribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) pathway.[1] Pyoluteorin was first isolated in the 1950s from Pseudomonas aeruginosa strains T359 and IFO 3455[2] and was found to be toxic against oomycetes, bacteria, fungi, and against certain plants.[3] Pyoluteorin is most notable for its toxicity against the oomycete Pythium ultimum,[4] which is a plant pathogen that causes a global loss in agriculture. Currently, pyoluteorin derivatives are being studied as an Mcl-1 antagonist in order to target cancers that have elevated Mcl-1 levels.[5]