title: Cyanopeptolins, new depsipeptides from the cyanobacterium Microcystis sp. PCC 7806.
abstract: Four depsipeptides (peptide lactones), called cyanopeptolins A, B, C and D, have been isolated from the cyanobacterium Microcystis sp. PCC 7806. They possess identical structures consisting of cyclic L-glutamic acid-gamma-aldehyde, L-leucine, N-methyl-phenylalanine, L-valine, L-threonine, L-aspartic acid, hexanoic acid and a variable basic amino acid. This variable amino acid can be L-arginine (cyanopeptolin A), L-lysine (cyanopeptolin B), N epsilon-methyl-L-lysine (cyanopeptolin C) and N epsilon,N epsilon-dimethyl-L-lysine (cyanopeptolin D), respectively. The L-glutamic acid-gamma-aldehyde and the amino group of L-leucine form an unusual 3-amino-6-hydroxy-2-oxo-1-piperidine system. L-Threonine is connected to L-valine via its hydroxy-group forming an ester bonding. The hexanoic acid residue is attached to the N-terminal aspartic acid residue which is not a part of the ring structure. The isolation procedure of the four cyanopeptolins as well as structure elucidation are described. Amino acid analysis, GC/MS analysis, FAB-MS and several NMR techniques were used to reveal the structures.
authors.affiliation: Institut für Biologie II, Albert-Ludwigs-Universität, Freiburg, F.R.G.
authors.forename: C
authors.initials: C
authors.lastname: Martin
authors.forename: L
authors.initials: L
authors.lastname: Oberer
authors.forename: T
authors.initials: T
authors.lastname: Ino
authors.forename: W A
authors.initials: WA
authors.lastname: König
authors.forename: M
authors.initials: M
authors.lastname: Busch
authors.forename: J
authors.initials: J
authors.lastname: Weckesser
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D005227:Fatty Acids / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry; D007783:Lactones / Q000032:analysis / Q000302:isolation & purification*; D046931:Microcystis / Q000737:chemistry*; D008969:Molecular Sequence Data; D010456:Peptides, Cyclic / Q000032:analysis / Q000302:isolation & purification*
chemical_list: D000596:Amino Acids; D005227:Fatty Acids; D007783:Lactones; D010456:Peptides, Cyclic