title: Tyropeptins A and B, new proteasome inhibitors produced by Kitasatospora sp. MK993-dF2. II. Structure determination and synthesis.
abstract: The structures of tyropeptins A and B, new proteasome inhibitors produced by Kitasatospora sp. MK993-dF2, were determined by analysis of various NMR experiments. The 1H and 13C NMR of tyropeptins were complicated due to the presence of an aldehyde group. Therefore, tyropeptins were converted to their alcohols by sodium borohydride. These alcohol derivatives gave assignable NMR spectra. The stereochemistry of tyropeptins were determined by analysis of acid hydrolysis products from tyropeptins, and further confirmed by the total synthesis. The structures of tyropeptins A and B were found to be isovaleryl-L-tyrosyl-L-valyl-DL-tyrosinal and n-butyryl-L-tyrosyl-L-leucyl-DL-tyrosinal, respectively.
authors.affiliation: Institute of Microbial Chemistry, Tokyo, Japan. imomose@bikaken.or.jp
authors.forename: I
authors.initials: I
authors.lastname: Momose
authors.forename: R
authors.initials: R
authors.lastname: Sekizawa
authors.forename: S
authors.initials: S
authors.lastname: Hirosawa
authors.forename: D
authors.initials: D
authors.lastname: Ikeda
authors.forename: H
authors.initials: H
authors.lastname: Naganawa
authors.forename: H
authors.initials: H
authors.lastname: Iinuma
authors.forename: T
authors.initials: T
authors.lastname: Takeuchi
mesh_terms: D003546:Cysteine Endopeptidases; D004151:Dipeptides / Q000138:chemical synthesis* / Q000737:chemistry; D004791:Enzyme Inhibitors / Q000138:chemical synthesis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D009097:Multienzyme Complexes / Q000037:antagonists & inhibitors; D046988:Proteasome Endopeptidase Complex; D013237:Stereoisomerism
chemical_list: D004151:Dipeptides; D004791:Enzyme Inhibitors; D009097:Multienzyme Complexes; C449021:tyropeptin A; C449020:tyropeptin B; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex