title: Scyptolin A and B, cyclic depsipeptides from axenic cultures of Scytonema hofmanni PCC 7110.
abstract: Two novel cyclic depsipeptides were isolated from axenic cultures of the terrestrial cyanobacterium Scytonema hofmanni PCC 7110 and designated scyptolin A and B. Amino acid analyses in context with mass and 1H/13C NMR spectroscopies revealed a composition typical for heterologous cyanopeptolins but containing the uncommon residue 3'-chloro-N-methyl-Tyr (cmTyr) and a unique sidechain. Scyptolin A and B both consist of the N-acylated peptide But(1)-Ala(2)-Thr(3)-Thr(4)-Leu(5)-Ahp(6) (3-amino-6-hydroxy-2-oxo-1-piperidine)-Thr(7)-cmTyr(8)-Val(9), which forms a 19-membered ring by esterification of the carboxyl of Val(9) with the hydroxyl of Thr(4). In scyptolin B, the hydroxyl of the Thr(3) residue is additionally esterified with N-butyroyl-Ala. Both scyptolin A and B exhibit selective inhibition of porcine pancreatic elastase in vitro with IC(50) values of 3.1 microg/ml.
authors.affiliation: Institut für Biologie II (Mikrobiologie), Albert-Ludwigs-Universität, Schänzlestrasse 1, D-79104 Freiburg i. Br., Germany. matern@uni-freiburg.de
authors.forename: U
authors.initials: U
authors.lastname: Matern
authors.forename: L
authors.initials: L
authors.lastname: Oberer
authors.forename: R A
authors.initials: RA
authors.lastname: Falchetto
authors.forename: M
authors.initials: M
authors.lastname: Erhard
authors.forename: W A
authors.initials: WA
authors.lastname: König
authors.forename: M
authors.initials: M
authors.lastname: Herdman
authors.forename: J
authors.initials: J
authors.lastname: Weckesser
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000458:Cyanobacteria / Q000737:chemistry*; D047630:Depsipeptides; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D019906:Nuclear Magnetic Resonance, Biomolecular; D010196:Pancreatic Elastase / Q000037:antagonists & inhibitors*; D010456:Peptides, Cyclic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D011487:Protein Conformation; D013552:Swine
chemical_list: D047630:Depsipeptides; D004791:Enzyme Inhibitors; D010456:Peptides, Cyclic; C448645:scyptolin A; C448646:scyptolin B; D010196:Pancreatic Elastase