Two polyketides neoenterocins A (1) and B (2), featuring a neighboring dicarbonyl motif and a furan-containing 5/6 ring system, were isolated from the enterocin producer Streptomyces sp. SCSIO 11863. Heterologous expression, gene disruptions, and isotope feeding experiments indicated that 1 and 2 were derived from the enterocin biosynthetic gene cluster. However, 2 was demonstrated as an artifact from enterocin via a unique skeleton rearrangement.