title: Spermidine as a potential biosynthetic precursor to the 1,5-diazabicyclo[4:3:o]nonene residue in the efrapeptins.
abstract: Efrapeptins are a group of microheterogeneous polypeptide antibiotics produced by the fungus Tolypocladium niveum, which are potent inhibitors of mitochondrial F1-ATPase. Efrapeptins contain an unusual 1,5-diazabicyclo[4:3:0]nonene (DBN) residue at the C-terminus. This study is driven by the hypothesis that the DBN residue could, in principle, arise by oxidative cyclization of a spermidine moiety. Electrospray ionization mass spectrometry of the peptide antibiotics 'elvapeptins' from T niveum establishes the presence of a C-terminal spermidine residue. Conversion of elvapeptins to efrapeptins by CuCl/pyridine demonstrates the transformation of the spermidine residue to the 1,5-diazabicyclo[4:3:0]nonene system by oxidative cyclization.
authors.affiliation: Molecular Biophysics Unit, Indian Institute of Science, Bangalore.
authors.forename: M V
authors.initials: MV
authors.lastname: Uma
authors.forename: R
authors.initials: R
authors.lastname: Sudha
authors.forename: P
authors.initials: P
authors.lastname: Balaram
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000737:chemistry*; D003300:Copper / Q000494:pharmacology; D013058:Mass Spectrometry; D008956:Models, Chemical; D008969:Molecular Sequence Data; D010100:Oxygen / Q000378:metabolism; D010455:Peptides / Q000737:chemistry; D017434:Protein Structure, Tertiary; D011725:Pyridines / Q000494:pharmacology; D017386:Sequence Homology, Amino Acid; D020037:Sordariales / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization; D013095:Spermidine / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D010455:Peptides; D011725:Pyridines; C012953:efrapeptin; D003300:Copper; C029892:cupric chloride; D010100:Oxygen; D013095:Spermidine