title: Cochinmicins, novel and potent cyclodepsipeptide endothelin antagonists from a Microbispora sp. II. Structure determination.
abstract: Cochinmicins I, II, and III are competitive endothelin antagonists produced by Microbispora sp. ATCC 55140. The cochinmicins are cyclic depsipeptides containing six alpha-amino acids and a pyrrolecarboxylic acid. Based upon MS, 1D and 2D NMR, and LC data, the structures and absolute stereochemistries of the cochinmicins have been assigned. All three components have the same basic sequence and contain one equivalent each of D-allo-threonine, D-alanine, L-phenylalanine, D-phenylalanine, 5-chloropyrrole-2-carboxylic acid (or pyrrole-2-carboxylic acid in cochinmicin I), plus two equivalents of 3,5-dihydroxyphenylglycine (DHPG). The phenylalanine residues were differentiated via a methanolysis product which contained only one of the phenylalanine residues. Both DHPG residues have the D configuration in the more active cochinmicins I and III. Cochinmicin II contains both D- and L-DHPG and these residues have been differentiated in the sequence based upon 1H NMR data.
authors: Merck Research Laboratories, Rahway, New Jersey 07065.
authors: D
authors: D
authors: Zink
authors: O D
authors: OD
authors: Hensens
authors: Y K
authors: YK
authors: Lam
authors: R
authors: R
authors: Reamer
authors: J M
authors: JM
authors: Liesch
mesh_terms: D000595:Amino Acid Sequence; D016232:Endothelins / Q000037:antagonists & inhibitors*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008848:Micromonosporaceae / Q000378:metabolism*; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D015394:Molecular Structure; D008970:Molecular Weight; D010456:Peptides, Cyclic / Q000737:chemistry*; D016339:Spectrometry, Mass, Fast Atom Bombardment
chemical_list: D016232:Endothelins; D010456:Peptides, Cyclic; C078833:cochinmicin I; C078835:cochinmicin II; C078836:cochinmicin III