Heronamides A-C, new polyketide macrolactams from an Australian marine-derived Streptomyces sp. A biosynthetic case for synchronized tandem electrocyclization.
A Streptomyces sp. isolated from a shallow water sediment sample collected off Heron Island, Australia, afforded three new polyketide macrolactams, heronamides A-C (1-3). Structures were assigned to the heronamides on the basis of detailed spectroscopic analysis, chemical derivatization and biosynthetic considerations. A plausible biosynthetic pathway is proposed in which key carbocyclic ring transformations proceed via an unprecedented synchronized tandem electrocyclization. This biosynthesis provides a framework for the assignment of complete relative configurations across all heronamides, and inspires an attractive biomimetic strategy for future total syntheses. Heronamide C elicits a dramatic and reversible non-cytotoxic effect on mammalian cell morphology.
Raju
Ritesh
R
Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland, Australia4072.
Piggott
Andrew M
AM
Conte
Melissa M
MM
Capon
Robert J
RJ
D001315:Australia; D002851:Chromatography, High Pressure Liquid; D047029:Lactams, Macrocyclic / Q000737:chemistry* / Q000378:metabolism; D018942:Macrolides / Q000737:chemistry; D013302:Streptomyces / Q000737:chemistry / Q000378:metabolism*
D047029:Lactams, Macrocyclic; D018942:Macrolides; C555720:heronamide C