Aranazoles: Extensively Chlorinated Nonribosomal Peptide-Polyketide Hybrids from the Cyanobacterium Fischerella sp. PCC 9339
Abstract
An analysis of cyanobacterial genomes revealed an architecturally unique biosynthetic gene cluster with an unusually high number of genes encoding predicted iron(II)/α-ketoglutarate-dependent halogenases. Mass spectrometry-guided identification of the corresponding metabolites yielded the aranazoles, extensively halogenated nonribosomal peptide− polyketide hybrids. Their chlorine-bearing fatty acyl-like moiety is reminiscent of the hyperhalogenated chlorosulfolipids, natural products of unknown enzymatic origin that were previously isolated from eukaryotic algae and mussels.